alkali and alkaline earth metals
TRANSCRIPT
Alkali and alkaline earth metals
Michael S. HillDOI: 10.1039/b716559p
The aim of this chapter is to reflect major advances in the coordination andorganometallic chemistry of the alkali and alkaline earth elements thatappeared in peer-reviewed journals throughout 2007. These self-imposedlimitations necessarily result in the omission of a great number of note-worthy advances in related fields rooted in either solid-state, materials ortheoretical chemistry. The author apologises in advance, therefore, that notall published work can be afforded the same depth of coverage.
Highlights
The undoubted highlight of 2007 occurred toward the end of the year with the report
by Jones and Stasch of the first stable magnesium(I) compounds containing a Mg–
Mg bond. Other highlights include the first magnesium boryls and the continued
growth of the fundamental and applied chemistry of calcium coordination com-
plexes.
1. Introduction
The stability of magnesium carbenoids and several new reactions based on the
electrophilicity of the magnesium carbenoids, including 1,3-CH insertion, have been
reviewed.1 The role of alkali metal cation complexants in the synthesis of alkalides
and electrides has been reviewed and discussed.2 Group 1 and 2 ‘ate’ compounds
have been the subject of a review which covers selected syntheses made possible by
their application as deprotonation reagents.3 Recent advances in the growing field of
calcium aryl chemistry have also been summarised in two separate reviews.4,5 The
mechanistic complexity with which lithium diisopropylamide metalates organic
substrates through a variety of mechanisms has been summarised, with particular
attention paid to the influence of solvation and aggregation on reactivity.6 A
comprehensive review of metal hydrides, including those of Groups 1 and 2, for
hydrogen storage has appeared.7
2. Lithium
The simplest possible chemical reduction process, the reaction of lithium atoms in
solid H2 has yielded the highly ionic rhombic dimer [(LiH)2]. [(LiH)n] oligomers have
also been investigated and have been suggested as having the potential to act as a
useful source of H2 gas.8
Department of Chemistry, University of Bath, Claverton Down, Bath, UK. E-mail:[email protected]; Fax: +44(0)1225 386231; Tel: +44(0)1225 383394
64 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
REVIEW www.rsc.org/annrepa | Annual Reports APu
blis
hed
on 3
0 A
pril
2008
. Dow
nloa
ded
by L
omon
osov
Mos
cow
Sta
te U
nive
rsity
on
20/1
1/20
13 0
1:48
:50.
View Article Online / Journal Homepage / Table of Contents for this issue
Group 14 donor ligands
Collisional activation of the lithiated betaine cation [(CH3)3NCH2CO2Li]+ (m/z
124) in the gas phase has resulted in decarboxylation to form the lithiated ylide
[(CH3)3NCH2Li]+.9 Highly diastereoselective lithiation-substitution reactions of an
(S)-proline derived S-alkyl thiocarbamate have been accomplished and the config-
uration of the predominant alkyllithium species deduced by X-ray analysis.10 The
highly reactive aggregate [{(nBuLi)2 �PMDTA}2] crystallised out of a 2:1 mixture ofnBuLi and PMDTA providing insight into the influence of the nBuLi/PMDTA ratio
on the course of some deprotonation reactions.11 (R,R)-N,N,N0,N0-tetramethyl-1,2-
diaminocyclohexane [(R,R)-TMCDA]-coordinated alkyllithiums have been found to
crystallise as dimeric ([MeLi � (R,R)-TMCDA]2 and [iPrLi � (R,R)-TMCDA]2) or
monomeric (sBuLi � (R,R)-TMCDA) species. The high reactivity of sBuLi � (R,R)-TMCDA in deprotonation reactions has been reasoned to result from the mono-
meric structure.12 In related work, (R,R)-TMCDA has been coordinate to tBuLi to
form a monomeric molecular structure.13
Reich and co-workers have performed low-temperature rapid injection NMR
(RINMR) experiments on nBuLi and 2-methoxy-6-(methoxymethyl)phenyllithium,
to measure the relative reactivity of the different aggregates toward typical electro-
philes. The measurements were concluded to demonstrate that the difference in
reactivity between the lower and higher aggregates of organolithium reagents can be
many orders of magnitude higher than all previous estimates.14 (Tributylstannyl)-
methyl 2,2,6,6-tetramethylpiperidine-1-carboxylate has been metalated with tBuLi/
TMEDA and borylated with the mixed borate derived from (R,R)-1,2-dicyclohex-
ylethane-1,2-diol and t-butanol to give diastereomeric boronates in equal amounts.
The configurations of the boronates and the chiral methyllithiums derived from
them were deduced from a single-crystal X-ray analysis of a carbamate in which the
tributylstannyl group had been replaced by the [(1R)-menthyl]dimethylstannyl
group.15 The oxygen-incorporating compound, [{(C7H7LiO)6(THF)(m-diglyme-k-O,k-O0)}]Li2O, obtained by lithiation of 2-bromomethoxybenzene with nBuLi has
been shown to comprise of an octahedral Li6O-unit, which is additionally capped by
lithium atoms at two facing Li3 triangles.16 It has been shown that asymmetric
substitution of 2-lithiopiperidines can be achieved by dynamic resolution in the
presence of a variety of bidentate chiral amine ligands.17 An investigation into the
mechanism and stereochemistry of chiral lithium-carbenoid-promoted cyclopropa-
nation reactions by using density functional theory (DFT) methods has demon-
strated that the intramolecular cyclopropanation reactions promoted by chiral
carbenoids proceed by the methylene-transfer mechanism.18
A number of reports relevant to a mechanistic understanding of lithium cuprate
addition reactions appeared in 2007. Investigation of reactions of a variety of methyl
Gilman reagents Me2CuLi �LiX with EtI using rapid-injection NMR spectroscopy
conditions has revealed a number of formally CuIII tetracoordinate square-planar
intermediates, including lithium ethyltrimethylcuprate(III), with a surprising range of
stabilities.19 A mesityl lithium amidocuprate complex has been characterized in the
solid state and shown to adopt a head-to-tail conformation. 2D-NMR spectroscopic
studies revealed the presence of several structural isomers in solution, including a
head-to-head isomer, resulting from a Schlenk equilibrium. The presence of these
isomers was postulated to have a significant influence on heterocuprate reactivity.20
In closely related research, the same group have reported the synthesis and
characterisation of two novel tetranuclear and thermally-stable lithium arylcuprates,
Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80 | 65
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
[Cu2Li2Mes4] and [Cu3LiMes4] � [Cu3LiMes4] was shown to be a highly active
promoter for the 1,4-addition of organolithiums to enones.21
The first triple-decker sandwich anion [(Z5-Cp)Li(Z5-Cp)Li(Z5-Cp)]� of lithocene
(Cp = C5H5) has been formed in the reaction of [Cp2V] with hppLi (hppH =
1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine). The VRV-bonded complex
[V2(hpp)4] effectively acts as a ligand to intercept the polymeric structure of
[CpLi]N.22 An aluminium ’ate’ base, iBu3Al(TMP)Li, has been developed for regio-
and chemo-selective direct generation of functionalised aromatic aluminium com-
pounds. The mechanism of directed ortho alumination of functionalised aromatic
compounds has been found to proceed with facile formation of an initial adduct of
the base and aromatic, followed by deprotonative formation of the functionalised
aromatic aluminium compound.23 Transition-state structures involving synergic
cooperation between lithium and zinc have been identified as crucial in determining
whether directed ortho-metalation or 1,2-addition occurs in the reaction of benzoni-
trile or methyl benzoate with Me2Zn(TMP)Li or (MeLi)2.24
The first example of a Li/Cl carbenoid that is stable at room temperature has been
prepared and the electronic reasons for this unusual thermal stability discussed on
the basis of DFT calculations. The reactivity of this carbenoid was investigated in
the formation of a palladium carbene complex.25 Sekiguchi and co-workers have
shown that reduction of tetrakis(di-tert-butylmethylsilyl)disilene with 2.2 equiva-
lents of Li or Na naphthalenide in THF results in the formation of the silylene anion
radical [(tBuMe2Si)2Si]d� as extremely air- and moisture-sensitive red crystals.26
Reactions of several trimethylsiloxychlorosilanes (Me3SiO)RR0SiCl with lithium
metal have been reported to lead to mixtures of compounds dependent upon the R
and R0 substituents.27 Reaction of spirostannabifluorene with methyllithium has
been shown to give lithium pentaorganostannate, the first example of a stable
organostannate having five carbon substituents. The X-ray structural analysis
revealed a slightly distorted trigonal bipyramidal structure.28 The synthesis of
several stannole anions has been described. The reduction of hexaphenylstannole
by lithium gave the 1,2,3,4,5-pentaphenylstannole anion, which reacted with di-
haloalkanes to give the corresponding bis(1-stannacyclopentadien-1-yl)alkanes. The
reactions of a related stannole dianion with an equimolar amount of bulky alkyl,
aryl, silyl, and stannyl halides gave the corresponding stannole anions.29
Group 15 donor ligands
Lithium hexamethyldisilazide (LiHMDS), has been studied by DFT methods. Four
THF molecules were considered the highest degree of THF solvation for the
monomer and the highest possible degree of aggregation for unsolvated LiHMDS
was determined to be four.30 The lithium salt of the bis-furyl substituted disilazide
anion, LiN(SiMe2R)2 [R = 2-methylfuryl] has been examined as a ligand transfer
reagent for the synthesis of magnesium and aluminium compounds.31 Treatment of
the sterically hindered enaminoimine TbtNHC(Me)CHC(Me)NAr [Tbt = 2,4,6-
{CH(SiMe3)2}C6H2] withnBuLi provided the corresponding lithium b-diketiminate,
[Li{TbtNHC(Me)CHC(Me)NAr}], as a monomeric, solvent-free species.32 Several
compounds based on the C1-symmetric ligands [N(R)C(Ar)NPh]� [Ar = C6H4Me-4
or Ph, R = SiMe3], including the lithium benzamidinates have been prepared by
insertion of the nitrile 4-MeC6H4CN or PhCN into the N–Li bond of LiN-
(SiMe3)Ph.33 Enolizations of 2-methylcyclohexanone by LiHMDS in the presence
of three bidentate chelating ligands revealed an approximate 40-fold range of rates
66 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
due to ligand-dependent structural differences in both the reactants and the transi-
tion structures.34 The X-ray crystal structures of a series of lithium quinolates,
lithium 8-hydroxyquinolinate (Liq), lithium 2-methyl-8-hydroxyquinolinate (Me-
Liq), and 2-phenyl-8-hydroxquinolinate (PhLiq), have been compared. Liq and
MeLiq molecules crystallise as hexamers, whereas PhLiq crystallises as a tetramer.35
Reaction of [MeNH3]Cl or [(tBuNH3)]Cl with LiAlH4 proceeds with H2 elimina-
tion, to give the imidoalanes Li2[(RN)4(AlH2)6] (R = Me or tBu). X-ray analysis of
the R = Me derivative revealed a structure in which the Li cations exist at two
distinct sites, each linked via Li(m-H)Al bridges to two [(MeN)4(AlH2)6]2� cages.36
Three Lewis base variations of the synthetically useful aluminate
[L �Li(TMP)(iBu)3Al], where L is TMPH, Et3N or PhC(QO)(NiPr2) have been
reported.37 Although it is inert towards conventional organomanganese reagents,
ferrocene can now be directly manganated by using a mixed lithium/manganese(II)
mixed dialkyl/amido reagent, [(TMEDA)Li(TMP)(R)Mn(R)] (R = CH2SiMe3).38
Sequential reaction of HTMP with nBuLi and Et2Zn has afforded unsolvated
polymer chains of EtZn(m-Et)(m-TMP)Li. The scope of this reagent in directed
ortho metalation chemistry has been tested by its reaction with N,N-diisopropyl-
naphthamide to give EtZn(m-C10H6C(O)(NiPr2)2)2Li � 2THF.39
Sequential treatment of Lewis acids with N,N0-bidentate ligands and tBuLi has
afforded a series of hydride-encapsulating alkali metal polyhedra. The guanidine
1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH) in conjunction with
Me2Zn/tBuLi yielded the interstitial hydride [(hpp)6HLi8]
+[(tBu3Zn)]� �PhMe.
The mixed borohydride/lithium hydride species [(hpp)6HLi8]+[Et3BH]� and
[(hpp)6HLi8]+[(Et3B)2H]� were also synthesised through the direct combination of
hppLi with Et3BHLi.40 Reactions mediated by lithium diisopropylamide (LDA)
with added hexamethylphosphoramide (HMPA) have been described. The N-
isopropylimine of cyclohexanone lithiates via monomer-based pathways while
conjugate addition of LDA/HMPA to an unsaturated ester proceeds via di and
tetra-HMPA-solvated dimers.41
Treatment of the lithium amide Li[NPh(SiMe3)] with 2,4,6-tri-t-butyl-1,3,5-tri-
phosphabenzene, P3C3tBu3, afforded equimolar amounts of the lithium salt of the
five-membered 2,4,5-tri-tert-butyl-1,3-diphospholide anion, LiP2C3tBu3, and the
tricyclic compound 6-[phenyl(trimethylsilyl)amino]-3,5,7-tri-tert-butyl-1,2,4,6-tetra-
phosphatricyclo[3.2.0.0(2.7)]hept-3-ene.42 Metallation of the secondary phosphanes
{(Me3Si)2CH}(C6H4-2-NMe2)PH and {(Me3Si)2CH}(2-C5H4N)PH with nBuLi gave
the lithium phosphanides [{(Me3Si)2CH}(C6H4-2-NMe2)PLi(THF)2] and
[{(Me3Si)2CH}(2-C5H4N)PLi].43
A wide range of polyfunctional aryl and heteroaryl magnesium reagents have been
efficiently prepared by direct magnesiation with (TMP)2Mg � 2LiCl. Furthermore,
these compounds can serve as intermediates in natural product synthesis.44 The
reactions of MCl3 with Li2[PhB(NtBu)2] in 1:2 molar ratios produced the bisbora-
amidinates LiM[PhB(NtBu)2]2 (M= As, Sb, Bi).45 The reaction of bis(3,5-dimethyl-
pyrazol-1-yl)methane with nBuLi and several carbodiimide derivatives has enabled
the preparation of several new heteroscorpionate ligands in the form of the lithium
derivatives.46 Deprotonation of di(benzothiazol-2-yl)phosphine, HP(bth)2, afforded
the lithium phosphanide [(Et2O)2)Li(bth)2P] with both nitrogen atoms coordinated
to the lithium atom. This complex was employed in the synthesis of the hetero-
bimetallic complex [Li(bth)2P{Mn(CO)2Cp}2]n in which the phosphorus atom
bridges two Mn(CO)2Cp residues.47
Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80 | 67
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
Group 16 donor ligands
A DGeq stability scale of secondary a-oxy-organolithium compounds has been
established from measurements of tin-lithium exchange equilibria in THF. A new
lead-lithium exchange equilibrium reaction was also reported.48 Lithium complexes
bearing dianionic amine bis(phenolate) ligands have been described. Reactions of
the ligand precursors Me2NCH2CH2N{CH2-2-HO-3,5-C6H2(tBu)2}2, (2-
C5H4N)CH2N{CH2-2-(HO)-3,5-C6H2(tBu)2}2 and MeOCH2CH2N{CH2-2-(HO)-
3,5-C6H2(tBu)2}2] with nBuLi afforded the dilithio species as tetra-nuclear com-
plexes, which showed excellent catalytic activities toward the ring-opening poly-
merisation of L-lactide in the presence of benzyl alcohol.49 The combination of
equimolar amounts of LiOAr and Mg(OAr)2 (OAr = aryloxide) has afforded
several lithium aryloxomagnesiates. Structural characterisation revealed several
discrete, solvent-separated species, including [Li(thf)4][Mg(BHT)3] �THF (BHT =
2,6-tBu2-4-MeC6H2O).50 An X-ray crystallographic study of an unusual lithium
silanolate hexamer, [LiO(SiMe2)OCH2SiMe3] has been described.51
3. Sodium
Dark-blue sodium nitride, Na3N, has been prepared by the reaction of metallic
sodium or liquid Na–K alloy with plasma-activated nitrogen at low pressure. The
compound crystallised in the cubic anti-ReO3-type structure according to powder
and single-crystal X-ray diffraction data.52 A unique 1-D chain of sodium clusters
containing Na6 rings and stabilised by a molybdenum-containing metalloligand has
been synthesised. DFT calculations revealed a resemblance in their aromatic
behaviour with the corresponding hydrocarbon analogues.53 A metallorganic gela-
tor formed from a mixture of a substituted nicotinic acid and its sodium salt has been
synthesised. The one-dimensional crystals were found to spontaneously gelify
dichloromethane and provide pyridine gels with high thermal resistance.54 The
structures of NaSCN, KSCN, RbSCN, and CsSCN complexes with 30,50-difluoro-
40-hydroxybenzyl-armed monoaza-15-crown-5 ether have been investigated. The Na
complex is a 1:1 polymer-like structure bridged by hydrogen bonding.55 Reaction of
zinc triflate with the lithium, sodium, and potassium salts of the bis(1,3-trimethyl-
silyl)allyl (A0) anion produced the fluxional triallylzincates Li[ZnA03], Na[ZnA03],
and K[ZnA03] rather than the initially expected neutral ZnA02.56 The reaction
between trimethylphosphine–borane and MeNa gave the polymeric complex
[{Me2P(BH3)CH2}Na(THF)]N.57 Reactions of the disodium salt of the 1,2-
bis[(2,6-diisopropylphenyl)imino]acenaphthene (Dipp-BIAN) ligand with one
equivalent of Me2AlCl produced [Na(Et2O)2(Dipp-BIAN)AlMe2], [Na(Z6-
C7H8)(Dipp-BIAN)AlMe2] and [Na(Z6-C6H6)(Dipp-BIAN)AlMe2]. The sodium
cation coordinates either one of the naphthalene rings or the diimine part of the
Dipp-BIAN ligand.58
The heavier alkali metal b-diketiminates [M{TbtNC(Me)CHC(Me)NMes}(THF)]
(Tbt = 2,4,6-[CH(SiMe3)2]C6H2; M=Na, K) have been prepared by the reaction of
the protonated ligand precursor, with MH (M = Na, K). Solvent-free
[M{TbtNC(Me)CHC(Me)NMes}] were prepared by the reaction of the Li derivative
with tBuOM (M = Na, K).32 Reaction of the sodium anion of (S)-N-(a-methyl-
benzyl)allylamine with t-butyl cinnamate resulted in a tandem aza–allyl conjugate
addition-Michael addition-ring closure reaction, to produce a chiral aminocyclo-
hexane containing six new vicinal stereogenic centres with excellent levels of
stereocontrol.59 Sodium and potassium salts of 1-methyl-3,5-diphenyl-4-
68 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
methylamino-1,2,4-triaza-3,5-diborolyl have been prepared by deprotonation of the
ring nitrogen in the neutral precursor.60 The ring closure of 1,2-diisopropylhydrazine
and 1,1-bis(phenylchloroboryl)ethane produced a heterocyclic compound with a
CB2N2 framework. Deprotonation of this precursor yielded 1,2-diisopropyl-4-
methyl-3,5-diphenyl-1,2-diaza-3,5-diborolyl, a cyclopentadienyl analogue contain-
ing only one carbon atom in the ring skeleton. Lithium, sodium, and potassium salts
of the new ligand have been prepared and characterized.61
It has been discovered that simple hydridoalkylzincates(II) can be prepared from
mixtures of sodium and an excess of neat dialkylzinc reagent.62 The Na and K salts
of the [Zn(C5H5)3]� ion have been found to exhibit polymeric 1D and 2D structures,
respectively. In contrast, the dizincate [Na(THF)6][Zn2(C5H5)5] contains discrete
[Zn2(C5H5)5]� ions that consist of two {Zn(C5H5)2} groups with Z1,Z1 binding,
bridged by a C5H5 ring Z1-coordinated to each zinc atom.63 Twofold deprotonation
of benzene by a sodium monoalkyl bisamido manganate(II) reagent derived fromnBuNa, TMPH and Mn(CH2SiMe3)2 has produced the first inverse-crown complex
in which the transition-metal atoms are incorporated in the host. Variable-tempera-
ture magnetisation measurements showed that the complex was antiferromagnetic.64
The first sodium–magnesium and sodium–zinc ketimido complexes display contrast-
ing inverse crown ring and pseudo-cubane structures respectively. A sodium–zinc
heterotrianionic alkyl–alkoxide–amide adopts a third type of structure with a
stepped ladder motif.65 Two new inverse crown alkali–metal–zinc enolate com-
pounds have been prepared by reaction of the relevant mixed-metal base
[MZn(HMDS)3] (M = Na, K) with a stoichiometric amount of the sterically
demanding ketone 2,4,6-trimethylacetophenone.66 A series of polypyrazolylalumi-
nates [Na{AltBu2pz)4�xMex] (x = 3, 2, 1) have been prepared by treatment of
[NatBu2pz)] with varying equivalents of AlMe3.67 The lithium phosphanide
[{(Me3Si)2CH}(C6H4-2-NMe2)P]Li(THF)2] undergoes metathesis with MOtBu
(M = Na, K) to give the heavier alkali metal derivatives [{(Me3Si)2CH}(C6H4-2-
NMe2)P]M(TMEDA)].43
Reaction of the imidazolidine-bridged bis(phenol) [ONNO]H2 ([ONNO]H2 =
1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)imidazolidine) with NaH provided {[ON-
NO]Na2(THF)2}2 � 2THF as a dimeric tetranuclear complex in an almost quantita-
tive yield.68 Mixed-metal alkoxide clusters of lanthanides and sodium
[Ln2Na8(OCH2CH2NMe2)12(OH)2] have been described as extremely active cata-
lysts for the ring-opening polymerisation of e-caprolactone and trimethylene carbo-
nate.69 From reactions between glycolide or lactide with 4-dimethylaminopyridine,
DMAP and NaBPh4 in benzene at 70 1C the cyclic ester adducts
(CH2C(O)O)6 �NaBPh4 and (CHMeC(O)O)6 �NaBPh4 were formed, respectively.
The mechanism for the formation of these 18-membered rings was discussed in terms
of an initial reaction between DMAP and NaBPh4 in hot benzene to produces NaPh
and DMAP: BPh3 in the presence of the monomer lactide.70 Reaction of the
polycyclic alumosiloxane [Ph2SiO]8[AlO(OH)]4 with either CpNa or with Me2Zn
produced [Ph2SiO]8[AlO2(Na)4 � 5(THF)] and [Ph2SiO]8[AlO(OH)]2[AlO2]2[Zn(OH)]2 � 2(OEt2), respectively.
71 The crystal structures of three hexameric double
heterocubane compounds containing NaOSiMePh2, each supported by THF and
[CpFe(CO)2]2 have been described.72 A series of sodium arylcyclotetrasiloxanolates
[4-RC6H4Si(O)ONa]4 and the corresponding (trimethylsiloxy)cyclotetrasiloxanes
[4-RC6H4Si(O)OSiMe3]4 (R = Cl, Br, CHQCH2, CH2Cl), have been prepared
as scaffolds for anchoring second order NLO active or fluorescent organic chromo-
phores.73 An organotin phosphonate oligomer composed of alternating
Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80 | 69
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
heptanuclear tin phenylphosphonate and hexanuclear sodium phenylphosphonate
clusters has been synthesised by a debenzylation process under solvothermal
conditions.74 The synthesis and structure of two related sodium complexes has been
reported which demonstrate that sulfur can preferentially complex to sodium
irrespective of the presence of more apposite donor species such as DMF.75 Sodium
and potassium carbamotelluroates [M(R2NCOTe), M = Na, K, Rb, Cs] have been
synthesised in moderate to good yields by reacting carbamoyl chloride with the
corresponding alkali metal tellurides.76
4. Potassium, rubidium and caesium
Reaction of elemental caesium with 1,3-bis(trimethylsilyl)propene produced the
corresponding substituted allyl derivative. The complex and its previously prepared
potassium counterpart form the THF solvates K[1,3-(SiMe3)2C3H3](THF)3/2 and
Cs[1,3-(SiMe3)2C3H3](THF), respectively, which crystallise as coordination poly-
mers in the solid state.77 Desilylation of Me3SiCHPh2 with K, Rb and Cs alkoxides
produced the diphenylmethanides which exist as both contact molecules and
separated ion pairs.78 Reaction between the phosphine-borane adduct (Me3Si)2-
CHPPh2(BH3) and MeK gave [(Me3Si)2[Ph2P(BH3)}C]K, which was crystallised as
the PMDETA adduct.79 Reaction of the iron(II) complex of the 1:3 Schiff base
condensate of tris(2-aminoethyl)amine (tren) with 2-imidazolecarbaldehyde, H3L1,
[FeH3L1](ClO4)2), with MClO4 (M=K, Rb, Cs, and NH4) produced double salts of
the formula [FeH3L1](ClO4)2 �MClO4.80
Solvated potassium salts of the 9-BBN hydroborate anion have been prepared and
their structures have been determined by single-crystal X-ray diffraction analyses. A
tetrameric complex [LK[(m-H)2BC8H14]4 is formed when L is toluene.81 The am-
moniate [K17(Sb8)2(NH2)] � 17.5NH3, which contains crown-shaped [Sb8]8� Zintl
anions analogous to S8 rings, has been synthesised by reduction of antimony with
potassium in liquid ammonia.82 RbNH2 � 2/3NH3, has been synthesised from
rubidium hydride in liquid ammonia at �78 1C. The structure contains a three-
dimensional network of amide anions and ammonia molecules, which are inter-
connected via hydrogen bonds.83
The reaction of potassium hexamethyldisilazide (KHMDS) with the bulky
formamidine N(Diep)QC(H)NH(Diep) (Diep-FormH, Diep = 2,6-Et2C6H3) in
THF yielded the half deprotonated compound [K(DiepForm)(DiepFormH)], which
exhibited suppressed reactivity with the hexamethyldisilazide anion. Preparation in
the presence of the chelating solvents DME and PMDETA gave the fully deproto-
nated species [{K3(DiepForm)3(DME)3}n]3 and [{K(PMDETA)K(DiepForm)2}n].84
A solution of 1,3-(4-nitrophenyl)triazene in methanol treated with potassium
hydroxide yielded dark-red crystalline blocks of [{K(O2NC6H4NNNC6H4NO2)}2]n,
a triazenide complex polymer of potassium in which the centrosymmetric binuclear
entities are connected by weak intermolecular (KO)–O–� � � interactions.85 Similarly,
3-(4-carboxyphenyl)-1-methyltriazene N-oxide reacts with KOH in methanol/pyr-
idine to give [K{O2C-C6H4N(H)NN(CH3)O} � 4H2O]n.86 3-tert-butyl-5-methyl-1,2,4-
triazole has been reacted with KBH4 to give a new potassium tris(3-tert-butyl-5-
methyl-1,2,4-triazolyl)borate ligand.87 The solid-state structures of unsolvated potas-
sium, rubidium, and cesium carbazolates have been determined using X-ray powder
diffraction data. The potassium and rubidium carbazolates adopt a polymeric helical
arrangement, whereas caesium carbazolate forms a polymeric twisted column struc-
ture.88 A coordination polymer, [(Cs(bth)2P}8] (bth= benzothiazol-2-yl), was obtained
70 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
when di(benzothiazol-2yl)phosphane was reacted with elemental caesium in a 1:1 ratio.
Each anion was coordinated to four caesium cations and vice versa.89
X-ray and neutron diffraction studies have shown that the controlled hydrolysis of
potassium 2-tert-butylphenoxide or 2-isopropylphenoxide leads to the encapsulation
of the water inside K6O6 hexameric drum aggregates through the formation of
strong hydrogen bonds and dative interactions between the host and guest.90 The
polysulfide [K2(THF)]S9 is accessible from reaction of S8 with [KSPPh2(BH3)], which
contains a S9-zigzag chain.91 The potassium salt of the anionic SPS pincer ligand
[K(THF)2][SPS(Me)] was isolated from reaction of the Li derivative with tBuOK.
Coordination of BH3 to the central phosphorus atom in [K(18-crown-
6)THF)][SPS(Me) �BH3] confirmed the phosphine character of the hypervalent
phosphorus atom.92 Potassium salts of chalcogenogermanate anions and their
corresponding hydrates have been prepared and crystallographically characterised.93
5. Beryllium
On the basis of quantum chemical calculations the multimetallocenes CpMnCp,
(M = Be, Mg, Ca, and Zn; n = 2–5) have been predicted to be thermodynamically
unstable with respect to loss of one metal atom except for the beryllium compounds,
which exhibit unusual stabilities in the gas phase for the whole series CpBenCp up to
n= 5.94 Beryllium has been successfully incorporated into a naphthalene-containing
Schiff base ligand. Evidence from 9Be and 1H NMR data and model compounds
indicated that the ligand completely encapsulates the beryllium cation via tetra-
dentate tetrahedral coordination using both phenol and imine donors.95 The binding
of beryllium to the iron transport protein transferrin has been found to proceed by
displacement of H+ from strong hydrogen bonds in the protein. This new view of
beryllium binding, in which beryllium behaves as a ‘‘tetrahedral proton’’, provides
insight into the transport mechanism of beryllium in chronic beryllium disease.96
The hexafluorodiberyllate (Ph4P)2[Be2F6] � 2CH3CN has been prepared by the reac-
tion of (Ph4P)2[Be2Cl6] with excess silver(I) fluoride in acetonitrile solution.97 (R,R)-
(N,N0)-diisopropylcyclohexyl-1,2-diamine reacts with equimolar amounts of BeCl2to give the donor acceptor complex ((R,R,S)-N,(S)-N)-[(C12H26N2)BeCl2]. The
reaction of this species with excess trimethylsilylazide led to the formation of the
corresponding azide.98 A Be phthalocyaninato(2�) complex with 4-picoline has been
obtained by recrystallisation of Be(II)Pc in 4-picoline under water-free conditions.99
Chloro-N0,N0-dimethylformamidinium (dimethylcyanamide)trichloroberyllate has
been prepared from BeCl2 and two equivalents of dimethylcyanamide.100 Single
crystals of [Be(OH2)4]Cl2 have been prepared by the reaction of thionyl chloride at
20 1C with HCl-containing, aqueous solutions of BeCl2.101
6. Magnesium
The reaction of boryllithium with 1 or 0.5 equivalents of MgBr2 has provided the
structurally characterised borylmagnesium bromide and bis(boryl)magnesium com-
plexes, 1 and 2. The reactivity of the borylmagnesium species with benzaldehyde was
different from that of the previously reported boryllithium.102 Single crystals of two
modifications of the new magnesium boride carbide MgB12C2, which conforms to
Wade’s Rules, have been synthesised from the elements.103 The crystal structure of
Mg(BH4)2 has been determined from synchrotron X-ray and neutron diffraction
data as a complex three-dimensional framework in which each Mg2+ ion is
tetrahedrally coordinated by four [BH4]� tetrahedra.104,105 A TMEDA complex of
Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80 | 71
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
Mg(BH4)2 has also been structurally characterised.106 The solid-state reaction of
MgBr2, MgBr2(Et2O) or MgBr2(Me2O)1.5 and NaB3H8 has afforded Mg(B3H8)2 and
the crystalline ether adducts respectively.107 The single-source precursors
[Mg(C3H6BC8H14)2] and [Mg{C3H6B(C6H11)2}2] have been applied in chemical
vapour deposition processes. Deposition procedures in a temperature range from
500 to 1000 1C produced smooth and thin films with Mg and B in the ratio 1:2.108
Group 14 donors
Bis(mesityl)magnesium has been established as an accessible, practical, convenient,
and non-nucleophilic carbon-centred base for efficient access to silyl enol ethers from
a series of ketone substrates.109 The reaction between either MgI2 or CaI2 and 2
equivalents of [(Me3Si)2{Me2(H3B)P}C]K provided the corresponding organo-alka-
line earth metal compounds [(Me3Si)2{Me2(H3B)P}C]2M in moderate to good
yields.110 Sequential addition of iPrMgCl and nBuLi to sp3 hybridised iodoalcohols
has been described. Interception of the resulting cyclic Grignard reagents with a
slight excess of an electrophile resulted in a diverse range of substituted alcohols.111
Group 15 donors
Reduction of two magnesium(II) iodide complexes with potassium metal in toluene
has provided the first thermally stable magnesium(I) compounds, LMgMgL (where
L is [DippNC(NiPr2)N(Dipp)]� or [{DippNC(Me)}2CH}]�, 3, in moderate yields.
The results of X-ray crystallographic and theoretical studies were consistent with
central Mg22+ units that have single, covalent magnesium–magnesium bonding
interactions with 2.8508(12) and 2.8457(8) A bond lengths, respectively, and
predominantly ionic interactions with the anionic ligands.112
A wide range of polyfunctional aryl and heteroaryl zinc reagents have been prepared
by direct zincation using (TMP)2Zn � 2MgCl2 � 2LiCl as an exceptionally active
base.113 A range of polyfunctionalised quinolines have been prepared via chemo-
and regio-selective magnesiation reactions using Mg reagents, such as iPrMgCl �LiCland TMP2Mg � 2LiCl.114 It has been reported that benzene can be easily 1,4-
dideprotonated on reaction with two equivalents of a synergic mixture of (tBu2Zn),
NaTMP and TMEDA to give a unique 1,4-dizincated benzene product which has
72 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
been characterised by X-ray crystallography.115 Several magnesium compounds
including [(dioxane)MgPh2]N and (THF)2Mg(NPh2)2 have been reported to tetra-
coordinate species.116,117 The transamination reaction of Mg[N(SiMe3)2]2 with (2-
pyridylmethyl)(tert-butyldimethylsilyl)amine yielded the corresponding homoleptic
magnesium bis[(2-pyridylmethyl)(tert-butyldimethylsilyl)amide].118 Magnesium and
zinc complexes of the monoanionic ligands N,N0-bis(2,6-diisopropylphenyl)triaze-
nide, N,N0-bis(2,6-diisopropylphenyl)acetamidinate and N,N0-bis(2,6-diisopropyl-
phenyl)(tert-butylamidinate) have been synthesised.119 Metallation of N-
(diphenylphosphanyl)-2-pyridylmethylamine with nBu2Mg resulted in the formation
of the magnesium bis[N-(diphenylphosphanyl)-2-pyridylmethylamide].120 The al-
kane elimination reaction between nBu2Mg and excess 3,5-diisopropylpyrazole
(iPr2PzH) has afforded the dinuclear magnesium pyrazolate [{Mg(iPr2P-
z)2(iPr2PzH)}2].
121 Reactions of {(tBuHN)3PNSiMe3 with nBu2Mg has yielded the
monodeprotonated complex [Mg{(NtBu)(NSiMe3)P(NHBu)2}2].122 The unusual
Mg4N4 cubane imide complexes [(ArNMg � dioxane)4 � 3(dioxane)] and
[(ArNMg �THF)4] (Ar = 2,4,6-Cl3C6H2) have been prepared by the equimolar
reaction of nBu2Mg with the primary amine.123 The coordination chemistry bis-[2-
(3,5-dimethyl-1-pyrazolyl)ethyl]amine (LH) with nBu2Mg and monoalkyl magne-
sium halides has been studied. Reaction of 2 equivalents of LH with nBu2Mg gave
the bis(amido) complex [L]2Mg while reactions with iPrMgCl and MeMgI afforded
the corresponding halide complexes.124 The reaction of 5-iodouracil with MeMgCl
followed by the addition of iPrMgCl �LiCl, has provided the corresponding trimag-
nesiated species, which reacts with various electrophiles to give selectively 5-
functionalized uracil derivatives.125 The mechanism for CO2 fixation by alkylmag-
nesium amides and magnesium bisamides has been analyzed on the basis by DFT
methods.126 The redox properties of the phthalocyanine-like tetrakis(thiadiazole)-
porphyrazine, [TTDPzMg], have been investigated by cyclic voltammetry and
density functional theory.127
Group 16 donors
A rare example of a structurally characterised magnesium alkyl alkoxide with an
Mg4O4 cubane structure, [Mg(CH2SiMe3)(m3-OCH2SiMe3)]4, has been identified as
the product of oxidation of ClMgCH2SiMe3 with traces of O2.128 Magnesium
complexes containing ketiminate ligands have been synthesized. nBu2Mg reacted
readily with two equivalents of [MeC(O)CHC(NHAr)Me] (Ar = 2,6-diisopropyl-
phenyl), to generate [MeC(O)CHC(NAr)Me]2Mg.129 Magnesium alkoxides have
been reported to undergo a hydride-transfer oxidation with benzaldehyde as the
oxidant. This magnesium variant of the Oppenauer oxidation has been used for the
synthesis of polyfunctional biaryl ketones.130 The magnesiation of halogenated
aromatic and heteroaromatic carboxylic acids has been accomplished by their
treatment with MeMgCl and subsequent reaction with iPrMgCl �LiCl. The resultingdouble-magnesiated species reacted with a variety of electrophiles in up to 97%
yield.131
7. Calcium, strontium and barium
Ca(NH2BH3)2 releases hydrogen over a temperature range of 100 to 170 1C without
foaming and has been described as a potential H2-storage material.132 The alkaline
earth tricyanomethanides Mg(tcm)2 � 2H2O, Ca(tcm)2, Sr(tcm)2 �H2O and
Ba(tcm)2 � 2H2O have been prepared from aqueous solutions of the respective
Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80 | 73
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
chlorides and solid silver tricyanomethanide.133 A series of trifluoroacetic acid
(H-TFA) derivatives of the heavier alkaline earths have been synthesised though
the dissolution of the alkaline earth metal in H-TFA.134
Although a monomeric calcium ‘carbene’ complex, [(2,6-iPr2C6H3NPPh2)2CCa],
has been reported to display sluggish reactivity toward unsaturated electrophiles, it
did act as catalyst for the oligomerisation of isocyanates.135 A related barium
complex, [(2,6-iPr2C6H3NPPh2)2CBa(THF)3], has also been described.136 A diaryl
calcium compound has also been isolated for the first time by fractionated crystal-
lization of mesitylcalcium iodide. Bis(2,4,6-trimethylphenyl)calcium and Tris(2,6-
dimethoxyphenyl)dicalcium iodide showed extremely high solubilities in THF even
at �90 1C.137 In related work, the transmetalation of phenylcopper and Ca metal
yielded the solvent-separated cuprate [(THF)3Ca(m-Ph)3Ca(THF)3]+[Ph–Cu–
Ph]�.138 Sterically hindered Lewis base free bis(1,2,4-tri-tert-butylcyclopentadienyl)-
strontium and bis(1,2,4-tri-tert-butylcyclopentadienyl)barium have been synthesised
and are suitable precursors for atomic layer deposition of thin films.139 Benzylcal-
cium complexes with modified fluorenyl ligands have been prepared and utilised as
initiators for syndiotactic styrene polymerisation.140
The structures of (DME)2Ca(NPh2)2, (THF)4Sr(NPh2)2 and (THF)4Ba(NPh2)2have been reported,116 as have a variety of routes to the closely related phenyl-
amides.117 Several diphenylphosphides including (THF)4Ca(PPh2)2 have also been
described.141,142 The diisopropylpyrazoloate [{Ca(iPr2Pz)2(iPr2PzH)2}2] has been
obtained as the product of redox-transmetallation/ligand-exchange reaction between
an excess of the metal, 2 equivalents of iPr2PzH, and Hg(C6F5)2. A similar reaction
with Sr metal led to the isolation of [Hg3(iPr2Pz)4(C6F5)2] while direct metallation of
barium with iPr2PzH afforded [{(Ba(iPr2Pz)2(py)3}2] upon treatment with pyri-
dine.121 A variety of new calcium b-diketiminate derivatives have been described
including simple amide and cyanide complexes.143 The reaction of a b-diketiminate-
stabilised calcium diphenylamide with the dialkylborane 9-BBN has allowed the
synthesis of a calcium borohydride along with an amidoborane reaction coproduct
via a likely sigma-bond metathesis mechanism.144 This compound was also included
in a broad study of the reactivity of the hydrocarbon–soluble calcium hydride
complex [{CH{(MeC)(DippN)}2}CaH(THF)}2] with a variety of substrates. Addi-
tion of this hydride to CQO and CQN functionalities gave easy access to calcium
alkoxide and amide complexes and addition to epoxides resulted in nucleophilic
ring-opening reactivity.145 A hydrocarbon–soluble dimeric calcium monofluoride,
[{CH{(MeC)(DippN)}2}CaF(THF)}2], 4, has been reported as a precursor for the
preparation of thin layers of transparent CaF2 at room temperature by dip-coat-
ing.146 A closely related fluoride complex, 5, has been reported as an intermediate in
the C–F cleavage decomposition of an unusual calcium b-diketiminate complex, 6,
which exhibits an unprecedented binding mode of a CF3 group.147
It has been reported that the azametallacyclopropane complex Ca(Z2-
Ph2CNPh)(HMPA)3 can be conveniently obtained via a one-pot procedure. Its
catalytic activity has been assayed in a variety of reactions.148 The b-diketiminato
74 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
[{CH{(MeC)(DippN)}2}Ca{N(SiMe3)2}(THF)] effects intermolecular hydropho-
sphination of a range of alkenes and alkynes. In behaviour reminiscent of lantha-
nocene(III) catalysis, a more electrophilic alkene was polymerised to phosphine-
terminated macromolecules.149 The mononuclear complex [{iPr2ATI}Ca-
{N(SiMe3)2}(THF)2] [iPr2ATI = N-isopropyl-2-(isopropylamino)troponiminate]
has been reported to display a high reactivity as a catalyst in the intramolecular
hydroamination/cyclisation reaction of nonactivated aminoalkenes.150 The synthesis
and structural characterization of an unusual trinuclear barium aminebis(phenolate)
complex has been described reported along with its application as an initiator for the
ring-opening polymerisation of e-caprolactone and L-lactide.151
A new class of heterobimetallic Group 1/Ba compound, e.g. [Li2(thf)2-
{Ba(Odpp)4}] (HOdpp = 2,6-diphenylphenol), which display significant metal–
arene interactions, has been reported.152 Inspired by the active site of Photosys-
tem-II, the cubane complex [Mn4Ca2Cl4(m-OCH2CH2OMe)8] has been described, in
which the calcium atoms result in a flattening of the Mn4 unit.153 Reaction between
BaI2 and NaOCH(CF3)2 in a 1:1 stoichiometry gave the heterometallic compound
NaBaI2(OCH(CF3)2)(H2O)(THF)0.5 which redistributed upon attempted crystal-
lisation.154 The products of reactions between the trifluoroacetates [Y(TFA)3-
(H2O)3], [Cu(TFA)2(MeOH)] and [Ba(TFA)2]N in the presence of excess N-
methyl-diethanolamine have been used as precursors for high Tc superconduc-
tors.155 Several dianionic bis beta-ketoesterates of barium, strontium and calcium
have been synthesised and studied as CVD precursors.156 Two complexes of calcium
croconate Ca(m3-C5O5)(H2O)3 and calcium oxalato-croconate Ca2(m4-C5O5)(m6-C2O4)(H2O) have been synthesised by soft chemical routes.157 Direct treatment of
2,6-dibenzylphenol (HOdbP) with strontium or barium metal in the absence of
solvent at high temperature has provided the corresponding phenolates Sr(OdbP)2and Ba(OdbP)2. Recrystallisation of Ba(OdbP)2 from THF gave a good yield of the
crystalline dimer [Ba(OdbP)2(THF)]2 � 2THF.158 The adducted salicylate com-
pounds, [Ca(SAL)2(phen)]n, [Sr2(SAL)4(phen)4] and (Ba(SAL)2(phen)2]n (SAL =
salicylate) have been obtained by the addition of 1,10-phenanthroline (phen) to the
corresponding base-free compounds.159
Ligand/reagent abbreviations
BHT 2,6-Di-tert-butyl-4-methylphenol
bth Benzothiazole
Cy Cyclohexyl
Diep 2,6-Diethylphenyl
Dipp 2,6-Diisopropylphenyl
Dippbian 1,2-Bis[(2,6-diisopropylphenyl)imino]acenaphthene
DFT Density functional theory
Dipp 2,6-Diisopropylphenyl
DME Dimethoxoethane
HMDS Hexamethyldisilazide
HMPA Hexamethylphosphoramide
HOdbP 2,6-Dibenzylphenol
hppH 1,3,4,6,7,8-Hexahydro-2H-pyrimido[1,2-a]pyrimidine
LDA Lithium diisoproylamide
Liq Lithium 8-hydroxyquinolate
Mes 2,4,6-Trimethylphenyl
PMDETA Pentamethyldiethylenetriamine
py Pyridyl
Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80 | 75
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
Pz Pyrazol-1-yl
SAL Salicylate
TFA Trifluoroacetate
thd 2,2,6,6-Tetramethylheptanedionate
THF Tetrahydrofuran
TMCDA Trans-N,N,N0,N0-tetramethylcyclohexanediamine
TMEDA N,N,N0,N0-Tetramethylethylenediamine
TMP 2,2,6,6-Tetramethylpiperidide
References
1 T. Satoh, Chem. Soc. Rev., 2007, 36, 1561.2 J. L. Dye, M. Y. Redko, R. H. Huang and J. E. Jackson, in Advances in Inorganic
Chemistry: Including Bioinorganic Studies, 2007, vol 59, pp. 205.3 R. E. Mulvey, F. Mongin, M. Uchiyama and Y. Kondo, Angewandte Chemie-Interna-
tional Edition, 2007, 46, 3802.4 M. Westerhausen, M. Gaertner, R. Fischer and J. Langer, Angewandte Chemie-Interna-
tional Edition, 2007, 46, 1950.5 M. Westerhausen, M. Gartner, R. Fischer, J. Langer, L. Yu and M. Reiher, Chemistry-a
European Journal, 2007, 13, 6292.6 D. B. Collum, A. J. McNeil and A. Ramirez, Angewandte Chemie-International Edition,
2007, 46, 3002.7 S. I. Orimo, Y. Nakamori, J. R. Eliseo, A. Zuttel and C. M. Jensen, Chem. Rev., 2007,
107, 4111.8 X. F. Wang and L. Andrews, Angewandte Chemie-International Edition, 2007, 46, 2602.9 R. A. J. O’Hair, T. Waters and B. Cao, Angewandte Chemie-International Edition, 2007,
46, 7048.10 R. P. Sonawane, C. Muck-Lichtenfeld, R. Frohlich, K. Bergander and D. Hoppe,
Chemistry-a European Journal, 2007, 13, 6419.11 C. Strohmann and V. H. Gessner, Angewandte Chemie-International Edition, 2007, 46,
4566.12 C. Strohmann and V. H. Gessner, J. Am. Chem. Soc., 2007, 129, 8952.13 C. Strohmann and V. H. Gessner, Angewandte Chemie-International Edition, 2007, 46,
8281.14 A. C. Jones, A. W. Sanders, M. J. Bevan and H. J. Reich, J. Am. Chem. Soc., 2007, 129,
3492.15 D. Kapeller, R. Barth, K. Mereiter and F. Hammerschmidt, J. Am. Chem. Soc., 2007,
129, 914.16 C. Strohmann and V. H. Gessner, Z. Anorg. Allg. Chem., 2007, 633, 2285.17 I. Coldham, J. J. Patel, S. Raimbault and D. T. E. Whittaker, Chem. Commun., 2007,
4534.18 Z. F. Ke, Y. B. Zhou, H. Gao, C. Y. Zhao and D. L. Phillips, Chemistry-a European
Journal, 2007, 13, 6724.19 S. H. Bertz, S. Cope, D. Dorton, M. Murphy and C. A. Ogle, Angewandte Chemie-
International Edition, 2007, 46, 7082.20 R. P. Davies, S. Hornauer and P. B. Hitchcock, Angewandte Chemie-International
Edition, 2007, 46, 5191.21 R. P. Davies, S. Hornauer and A. J. P. White, Chem. Commun., 2007, 304.22 C. Fernandez-Cortabitarte, F. Garcia, J. V. Morey, M. McPartlin, S. Singh, A. E. H.
Wheatley and D. S. Wright, Angewandte Chemie-International Edition, 2007, 46, 5425.23 H. Naka, M. Uchiyama, Y. Matsumoto, A. E. H. Wheatley, M. McPartlin, J. V. Morey
and Y. Kondo, J. Am. Chem. Soc., 2007, 129, 1921.24 M. Uchiyama, Y. Matsumoto, S. Usui, Y. Hashimoto and K. Morokuma, Angewandte
Chemie-International Edition, 2007, 46, 926.25 T. Cantat, X. Jacques, L. Ricard, X. F. Le Goff, N. Mezailles and P. Le Floch,
Angewandte Chemie-International Edition, 2007, 46, 5947.26 S. Inoue, M. Ichinohe and A. Sekiguchi, J. Am. Chem. Soc., 2007, 129, 6096.27 J. Harloff, E. Popowski and H. Reinke, J. Organomet. Chem., 2007, 692, 1421.28 M. Saito, S. Imaizumi, T. Tajima, K. Lshimura and S. Nagase, J. Am. Chem. Soc., 2007,
129, 10974.29 R. Haga, M. Saito and M. Yoshioka, Eur. J. Inorg. Chem., 2007, 1297.
76 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
30 S. Popenova, R. C. Mawhinney and G. Schreckenbach, Inorg. Chem., 2007, 46, 3856.31 L. T. J. Evans, M. P. Coles, F. G. N. Cloke and P. B. Hitchcock, J. Organomet. Chem.,
2007, 692, 2548.32 H. Hamaki, N. Takeda, T. Yamasaki, T. Sasamori and N. Tokitoh, J. Organomet.
Chem., 2007, 692, 44.33 P. B. Hitchcock, M. F. Lappert and P. G. Merle, Dalton Transactions, 2007, 585.34 P. F. Godenschwager and D. B. Collum, J. Am. Chem. Soc., 2007, 129, 12023.35 M. Rajeswaran, W. J. Begley, L. P. Olson and S. Huo, Polyhedron, 2007, 26, 3653.36 C. Y. Tang, A. R. Cowley, A. J. Downs and S. Parsons, Inorg. Chem., 2007, 46, 5439.37 J. Garcia-Alvarez, E. Hevia, A. R. Kennedy, J. Klett and R. E. Mulvey, Chem. Commun.,
2007, 2402.38 J. Garcia-Alvarez, A. R. Kennedy, J. Klett and R. E. Mulvey, Angewandte Chemie-
International Edition, 2007, 46, 1105.39 Y. Kondo, J. V. Morey, J. C. Morgan, H. Naka, D. Nobuto, P. R. Raithby, M.
Uchiyama and A. E. H. Wheatley, J. Am. Chem. Soc., 2007, 129, 12734.40 S. R. Boss, M. P. Coles, V. Eyre-Brook, F. Garcia, R. Haigh, P. B. Hitchcock, M.
McPartlin, J. V. Morey, H. Naka, P. R. Raithby, H. A. Sparkes, C. W. Tate and A. E. H.Wheatley, Dalton Transactions, 2006, 5574.
41 Y. Ma and D. B. Collum, J. Am. Chem. Soc., 2007, 129, 14818.42 S. B. Clendenning, P. B. Hitchcock, M. F. Lappert, P. G. Merle, J. F. Nixon and L.
Nyulaszi, Chemistry-a European Journal, 2007, 13, 7121.43 K. Izod, J. C. Stewart, W. Clegg and R. W. Harrington, Dalton Transactions, 2007, 257.44 G. C. Clososki, C. J. Rohbogner and P. Knochel, Angewandte Chemie-International
Edition, 2007, 46, 7681.45 J. Konu, M. S. Balakrishna, T. Chivers and T. W. Swaddle, Inorg. Chem., 2007, 46, 2627.46 A. Otero, J. Fernandez-Baeza, A. Antinolo, J. Tejeda, A. Lara-Sanchez, L. F. Sanchez-
Barba, I. Lopez-Solera and A. M. Rodriguez, Inorg. Chem., 2007, 46, 1760.47 T. Stey, J. Henn and D. Stalke, Chem. Commun., 2007, 413.48 P. Monje, P. Grana, M. R. Paleo and F. J. Sardina, Chemistry-a European Journal, 2007,
13, 2277.49 C. A. Huang and C. T. Chen, Dalton Transactions, 2007, 5561.50 M. F. Zuniga, J. Kreutzer, W. Teng and K. Ruhlandt-Senge, Inorg. Chem., 2007, 46,
10400.51 C. Jones and A. F. Richards, Main Group Met. Chem., 2006, 29, 173.52 G. V. Vajenine, Inorg. Chem., 2007, 46, 5146.53 S. Khatua, D. R. Roy, P. K. Chattaraj and M. Bhattacharjee, Chem. Commun., 2007,
135.54 D. Bardelang, F. Camerel, A. C. G. Hotze, B. Kariuki, B. Paik, M. Schmutz, R. Ziessel
and M. J. Hannon, Chemistry-a European Journal, 2007, 13, 9277.55 Y. Habata, C. Okazaki, K. Ogura, S. Akabori, X. X. Zhang and J. S. Bradshaw, Inorg.
Chem., 2007, 46, 8264.56 C. K. Gren, T. P. Hanusa and A. L. Rheingold, Organometallics, 2007, 26, 1643.57 K. Izod, C. Wills, W. Clegg and R. W. Harrington, Organometallics, 2007, 26, 2861.58 H. Schumann, M. Hummert, A. N. Lukoyanov and I. L. Fedushkin, Chemistry-a
European Journal, 2007, 13, 4216.59 M. Koutsaplis, P. C. Andrews, S. D. Bull, P. J. Duggan, B. H. Fraser and P. Jensen,
Chem. Commun., 2007, 3580.60 H. V. Ly, J. H. Chow, M. Parvez, R. McDonald and R. Roesler, Inorg. Chem., 2007, 46,
9303.61 H. V. Ly, T. D. Forster, A. M. Corrente, D. J. Eisler, J. Konu, M. Parvez and R. Roesler,
Organometallics, 2007, 26, 1750.62 A. Lennartson, M. Hakansson and S. Jagner, Angewandte Chemie-International Edition,
2007, 46, 6678.63 E. Alvarez, A. Grirrane, I. Resa, D. del Rio, A. Rodriguez and E. Carmona, Angewandte
Chemie-International Edition, 2007, 46, 1296.64 L. M. Carrella, W. Clegg, D. V. Graham, L. M. Hogg, A. R. Kennedy, J. Klett, R. E.
Mulvey, E. Rentschler and L. Russo, Angewandte Chemie-International Edition, 2007, 46,4662.
65 W. Clegg, S. H. Dale, D. V. Graham, R. W. Harrington, E. Hevia, L. M. Hogg, A. R.Kennedy and R. E. Mulvey, Chem. Commun., 2007, 1641.
66 S. E. Baillie, E. Hevia, A. R. Kennedy and R. E. Mulvey, Organometallics, 2007, 26, 204.67 S. A. Cortes-Llamas and M. A. Munoz-Hernandez, Organometallics, 2007, 26, 6844.68 X. P. Xu, Y. M. Yao, Y. Zhang and Q. Shen, Inorg. Chem., 2007, 46, 3743.
Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80 | 77
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
69 H. T. Sheng, F. Xu, Y. M. Yao, Y. Zhang and Q. Shen, Inorg. Chem., 2007, 46, 7722.70 M. H. Chisholm, J. C. Gallucci and H. Yin, Dalton Transactions, 2007, 4811.71 M. Veith, H. Hreleva-Carparrotti and V. Huch, J. Organomet. Chem., 2007, 692, 2784.72 T. I. Kuckmann, M. Bolte, M. Wagner and H. W. Lerner, Z. Anorg. Allg. Chem., 2007,
633, 290.73 M. Ronchi, M. Pizzotti, A. O. Biroli, P. Macchi, E. Lucenti and C. Zucchi, J. Organomet.
Chem., 2007, 692, 1788.74 S. Y. Song, J. F. Ma, J. Yang, L. L. Gao and Z. M. Su, Organometallics, 2007, 26, 2125.75 A. Biernat, M. Schwalbe, D. Wallace, J. Reglinski andM. D. Spicer,Dalton Transactions,
2007, 2242.76 K. Ibi, T. Imase, S. Kato, F. Ando and J. Koketsu, Zeitschrift Fur Anorganische Und
Allgemeine Chemie, 2007, 633, 635.77 K. T. Quisenberry, C. K. Gren, R. E. White, T. P. Hanusa and W. W. Brennessel,
Organometallics, 2007, 26, 4354.78 J. S. Alexander, D. G. Allis, W. J. Teng and K. Ruhlandt-Senge, Chemistry-a European
Journal, 2007, 13, 9899.79 K. Izod, C. Wills, W. Clegg and R. W. Harrington, J. Organomet. Chem., 2007, 692, 5060.80 G. Brewer, R. J. Butcher, C. Viragh and G. White, Dalton Transactions, 2007, 4132.81 X. N. Chen, S. M. Liu, B. Du, E. A. Meyers and S. G. Shoren, Eur. J. Inorg. Chem., 2007,
5563.82 M. Reil and N. Korber, Z. Anorg. Allg. Chem., 2007, 633, 1599.83 T. Scheubeck and N. Korber, Z. Anorg. Allg. Chem., 2007, 633, 2641.84 M. L. Cole, A. J. Davies, C. Jones and P. C. Junk, J. Organomet. Chem., 2007, 692, 2508.85 M. Horner, A. M. da Silva and H. Fenner, Z. Anorg. Allg. Chem., 2007, 633, 776.86 M. Horner, G. M. de Oliveira and A. dos Santos, Z. Anorg. Allg. Chem., 2007, 633, 971.87 F. E. Jernigan, N. A. Sieracki, M. T. Taylor, A. S. Jenkins, S. E. Engel, B. W. Rowe, F.
A. Jove, G. P. A. Yap, E. T. Papish and G. M. Ferrence, Inorg. Chem., 2007, 46, 360.88 R. Dinnebier, H. Esbak, F. Olbrich and U. Behrens, Organometallics, 2007, 26, 2604.89 T. Stey, M. Pfeiffer, J. Henn, S. K. Pandey and D. Stalke, Chemistry-a European Journal,
2007, 13, 3636.90 J. J. Morris, B. C. Noll, A. J. Schultz, P. M. B. Piccoli and K. W. Henderson, Inorg.
Chem., 2007, 46, 10473.91 F. Dornhaus, M. Bolte, M. Wagner and H. W. Lerner, Z. Anorg. Allg. Chem., 2007, 633,
425.92 M. Doux, P. Thuery, M. Blug, L. Ricard, P. Le Floch, T. Arliguie and N. Mezailles,
Organometallics, 2007, 26, 5643.93 M. Melullis and S. Dehnen, Z. Anorg. Allg. Chem., 2007, 633, 2159.94 A. Velazquez, I. Fernandez, G. Frenking and G. Merino, Organometallics, 2007, 26,
4731.95 P. G. Plieger, K. D. John and A. K. Burrell, Polyhedron, 2007, 26, 472.96 T. M. McCleskey, D. S. Ehler, T. S. Keizer, D. N. Asthagiri, L. R. Pratt, R. Michalczyk
and B. L. Scott, Angewandte Chemie-International Edition, 2007, 46, 2669.97 R. Tonner, G. Frenking, B. Neumuller and K. Dehnicke, Z. Anorg. Allg. Chem., 2007,
633, 1183.98 B. Neumuller and K. Dehnicke, Z. Anorg. Allg. Chem., 2007, 633, 2262.99 R. Kubiak, J. Janczak, M. Sledz and E. Bukowska, Polyhedron, 2007, 26, 4179.100 B. Neumuller and K. Dehnicke, Z. Anorg. Allg. Chem., 2007, 633, 103.101 W. Massa and K. Dehnicke, Z. Anorg. Allg. Chem., 2007, 633, 1366.102 M. Yamashita, Y. Suzuki, Y. Segawa and K. Nozaki, J. Am. Chem. Soc., 2007, 129, 9570.103 V. Adasch, K. U. Hess, T. Ludwig, N. Vojteer and H. Hillebrecht, Chemistry-a European
Journal, 2007, 13, 3450.104 R. Cerny, Y. Filinchuk, H. Hagemann and K. Yvon, Angewandte Chemie-International
Edition, 2007, 46, 5765.105 P. Zanella, L. Crociani, N. Masciocchi and G. Giunchi, Inorg. Chem., 2007, 46, 9039.106 G. L. Soloveichik, M. Andrus and E. B. Lobkovsky, Inorg. Chem., 2007, 46, 3790.107 D. Y. Kim, Y. Yang, J. R. Abelson and G. S. Girolami, Inorg. Chem., 2007, 46, 9060.108 S. Mathur, T. Rugamer, H. Braunschweig and G. D’Andola, Z. Anorg. Allg. Chem.,
2007, 633, 2459.109 W. J. Kerr, A. J. B. Watson and D. Hayes, Chem. Commun., 2007, 5049.110 K. Izod, C. Wills, W. Clegg and R. W. Harrington, Inorg. Chem., 2007, 46, 4320.111 F. F. Fleming, S. Gudipati, V. A. Vu, R. J. Mycka and P. Knochel, Org. Lett., 2007, 9,
4507.112 S. P. Green, C. Jones and A. Stasch, Science, 2007, 318, 1754.
78 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
113 S. H. Wunderlich and P. Knochel, Angewandte Chemie-International Edition, 2007, 46,7685.
114 N. Boudet, J. R. Lachs and P. Knochel, Org. Lett., 2007, 9, 5525.115 D. R. Armstrong, W. Clegg, S. H. Dale, D. V. Graham, E. Hevia, L. M. Hogg, G. W.
Honeyman, A. R. Kennedy and R. E. Mulvey, Chem. Commun., 2007, 598.116 M. Gartner, R. Fischer, J. Langer, H. Gorls, D. Walther and M. Westerhausen, Inorg.
Chem., 2007, 46, 5118.117 M. Gartner, H. Gorls and M. Westerhausen, Inorg. Chem., 2007, 46, 7678.118 C. Koch, A. Malassa, C. Agthe, H. Gorls, R. Biedermann, H. Krautscheid and M.
Westerhausen, Z. Anorg. Allg. Chem., 2007, 633, 375.119 N. Nimitsiriwa, V. C. Gibson, E. L. Marshall, P. Takolpuckdee, A. K. Tomov, A. J. P.
White, D. J. Williams, M. R. J. Elsegood and S. H. Dale, Inorg. Chem., 2007, 46, 9988.120 D. Olbert, A. Kalisch, N. Herzer, H. Gorls, P. Mayer, L. Yu, M. Reiher and M.
Westerhausen, Z. Anorg. Allg. Chem., 2007, 633, 893.121 J. Hitzbleck, G. B. Deacon and K. Ruhlandt-Senge, Eur. J. Inorg. Chem., 2007, 592.122 S. D. Robertson, T. Chivers and J. Konu, J. Organomet. Chem., 2007, 692, 4327.123 J. A. Rood, B. C. Noll and K. W. Henderson, Inorg. Chem., 2007, 46, 7259.124 B. Lian, C. M. Thomas, O. L. Casagrande, T. Roisnel and J. F. Carpentier, Polyhedron,
2007, 26, 3817.125 F. Kopp and P. Knochel, Org. Lett., 2007, 9, 1639.126 H. J. Himmel, Z. Anorg. Allg. Chem., 2007, 633, 2191.127 M. P. Donzello, C. Ercolani, K. M. Kadish, G. Ricciardi, A. Rosa and P. A. Stuzhin,
Inorg. Chem., 2007, 46, 4145.128 C. A. Moreno, D. L. Hughes and M. Bochmann, Polyhedron, 2007, 26, 2523.129 W. Y. Lee, H. H. Hsieh, C. C. Hsieh, H. M. Lee, G. H. Lee, J. H. Huang, T. C. Wu and S.
H. Chuang, J. Organomet. Chem., 2007, 692, 1131.130 R. J. Kloetzing, A. Krasovskiy and P. Knochel, Chemistry-a European Journal, 2007, 13,
215.131 F. Kopp, S. Wunderlich and P. Knochel, Chem. Commun., 2007, 2075.132 H. V. K. Diyabalanage, R. P. Shrestha, T. A. Semelsberger, B. L. Scott, M. E. Bowden,
B. L. Davis and A. K. Burrell, Angewandte Chemie-International Edition, 2007, 46, 8995.133 K. E. Bessler, C. C. Gatto, L. L. Romualdo, J. A. Ellena and M. Sales, Main Group Met.
Chem., 2007, 30, 135.134 T. J. Boyle, H. D. Pratt, T. M. Alam, M. A. Rodriguez and P. G. Clem, Polyhedron, 2007,
26, 5095.135 L. Orzechowski and S. Harder, Organometallics, 2007, 26, 2144.136 L. Orzechowski and S. Harder, Organometallics, 2007, 26, 5501.137 R. Fischer, M. Gartner, H. Gorls, L. Yu, M. Reiher and M. Westerhausen, Angewandte
Chemie-International Edition, 2007, 46, 1618.138 R. Fischer, H. Gorls and M. Westerhausen, Organometallics, 2007, 26, 3269.139 T. Hatanpaa, M. Ritala and M. Leskela, J. Organomet. Chem., 2007, 692, 5256.140 D. F. J. Piesik, K. Habe and S. Harder, Eur. J. Inorg. Chem., 2007, 5652.141 M. Gartner, H. Gorls and M. Westerhausen, Z. Anorg. Allg. Chem., 2007, 633, 2025.142 M. R. Crimmin, A. G. M. Barrett, M. S. Hill, P. B. Hitchcock and P. A. Procopiou,
Inorganic Chemistry, 2007, 46, 10410.143 C. Ruspic and S. Harder, Inorg. Chem., 2007, 46, 10426.144 A. G. M. Barrett, M. R. Crimmin, M. S. Hill, P. B. Hitchcock and P. A. Procopiou,
Organometallics, 2007, 26, 4076.145 J. Spielmann and S. Harder, Chemistry-a European Journal, 2007, 13, 8928.146 S. Nembenna, H. W. Roesky, S. Nagendran, A. Hofmeister, J. Magull, P. J. Wilbrandt
and M. Hahn, Angewandte Chemie-International Edition, 2007, 46, 2512.147 A. G. M. Barrett, M. R. Crimmin, M. S. Hill, P. B. Hitchcock and P. A. Procopiou,
Angewandte Chemie-International Edition, 2007, 46, 6339.148 F. Buch and S. Harder, Organometallics, 2007, 26, 5132.149 M. R. Crimmin, A. G. M. Barrett, M. S. Hill, P. B. Hitchcock and P. A. Procopiou,
Organometallics, 2007, 26, 2953.150 S. Datta, P. W. Roesky and S. Blechert, Organometallics, 2007, 26, 4392.151 M. G. Davidson, C. T. O’Hara, M. D. Jones, C. G. Keir, M. F. Mahon and G. Kociok-
Kohn, Inorg. Chem., 2007, 46, 7686.152 M. F. Zuniga, G. B. Deacon and K. Ruhlandt-Senge, Chemistry-a European Journal,
2007, 13, 1921.153 L. B. Jerzykiewicz, J. Utko, M. Duczmal and P. Sobota, Dalton Transactions, 2007, 825.154 S. Mishra, L. G. H. Pfalzgraf and E. Jeanneau, Polyhedron, 2007, 26, 66.
Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80 | 79
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online
155 S. Mishra, J. Y. Zhang, L. G. Hubert-Pfalzgraf, D. Luneau and E. Jeanneau, Eur. J.Inorg. Chem., 2007, 602.
156 M. R. Hill, J. J. Russell, N. K. Roberts and R. N. Lamb, Polyhedron, 2007, 26, 493.157 E. Gavilan and N. Audebrand, Polyhedron, 2007, 26, 5533.158 M. L. Cole, G. B. Deacon, C. M. Forsyth, P. C. Junk, K. M. Proctor, J. L. Scott and C.
R. Strauss, Polyhedron, 2007, 26, 244.159 R. Murugavel and R. Korah, Inorg. Chem., 2007, 46, 11048.
80 | Annu. Rep. Prog. Chem., Sect. A, 2008, 104, 64–80
This journal is �c The Royal Society of Chemistry 2008
Publ
ishe
d on
30
Apr
il 20
08. D
ownl
oade
d by
Lom
onos
ov M
osco
w S
tate
Uni
vers
ity o
n 20
/11/
2013
01:
48:5
0.
View Article Online