S1

Supporting Information for

When long bis(pyrazolates) meet late transition

metals: structure, stability and adsorption of

MOFs featuring large parallel channels

Simona Galli,* Angelo Maspero,

* Carlotta Giacobbe,

Giovanni Palmisano, Luca Nardo, Angiolina Comotti,

Irene Bassanetti, Piero Sozzani, Norberto Masciocchi

Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.This journal is © The Royal Society of Chemistry 2014

S2

Figure S1. Final Rietveld refinement plots for a) [Ni(BPEB)], b) αααα-[Zn(BPEB)], and c)

[Fe2(BPEB)3], in terms of experimental (blue), calculated (red) and difference (grey) patterns. The

positions of the Bragg reflections are indicated with blue marks at the bottom. The high-angle

portion of the diffractograms has been magnified (4×) for the sake of clarity. Horizontal axis: 2θ,

deg; vertical axis: intensity, counts.

Me77_NiL5 100.00 %Me77_NiL5 100.00 %

4 ×

5 15 25 35 45 55 65 75 85 95 105

2θθθθ , deg

(a)

[Zn(L5)] 100.00 %

5 15 25 35 45

[Zn(L5)] 100.00 %

4 ×

2θθθθ, deg

(b)

55 65 75 85 95 105

(c)

FeL5 100.00 %

5 15 25 35 45

2θθθθ , deg

FeL5 100.00 %

55 65 75 85 95 105

4 ×

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Figure S2. Low-angle portion of the XRPD patterns acquired on different preparations of αααα-

[Zn(BPEB)] and ββββ-[Zn(BPEB)]. The difference between a prototypical pattern of the former

(black curve) and one of the latter (orange curve), in terms of relative intensities of the peaks, is

evident, above all for the first two Bragg reflections, for which the ratio of the peak intensities is

reported on the right.

Figure S3. a) Electronic density map produced with the structure factors observed for ββββ-

[Zn(BPEB)]. b) Electronic density map produced with the structure factors calculated with the

doubly interpenetrated network found in αααα-[Zn(BPEB)]. By comparing the two maps, it is evident

that the doubly interpenetrated network describes only a part of the observed electronic density, that

in the channels remaining at present unexplained, but possibly attributable to another [Zn(BPEB)]

network incommensurate with the “major” one.

2θθθθ , deg4 10 2015

Ratio: 11.29

Ratio: 0.63

Ratio: 0.71

Ratio: 0.29

(a) (b)

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Figure S4. Traces of the thermogravimetric analyses (green) and the differential scanning

calorimetry (blue) carried out for a) [Ni(BPEB)], b) [Fe2(BPEB)3], c) αααα-[Zn(BPEB)], and d) ββββ-

[Zn(BPEB)] in a flux of nitrogen at a rate of 10 °C/min.

Temperature, °C

Wt%

Heat (mW/mg)↑ exo

(b)

200 300 400 500 600 700 800100

0.0

1.0

2.0

3.0

4.0

433 °C

415 °C100

90

80

70

60

Temperature, °C

422 °C

-20.7%

-5.0%

100

200 300 400 500 600 700 800

90

80

70

60

Wt%

100

0.0

1.0

2.0

3.0

4.0

(a)

Heat (mW/mg)↑ exo

Temperature, °C

Wt%

Heat (mW/mg)↑ exo

(c)

200 300 400 500 600 700 800100

100

90

80

70

60

405 °C

-19.9%

491 °C

469 °C

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0402 °C

510 °C-16.2%

510 °C

Temperature, °C

Wt%Heat (mW/mg)

↑ exo

(d)

200 300 400 500 600 700 800100

100

90

80

70

60-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

S5

Figure S5. a) Plot of the X-ray powder diffraction patterns measured on [Ni(BPEB)] as a function

of the temperature heating, with steps of 20 °C, up to decomposition. The permanent porosity of

species [Ni(BPEB)] can be appreciated. b) Percentage variation of the unit cell parameters (pT) of

[Ni(BPEB)] as a function of the temperature. The values at 30 °C (p30) have been taken as the

references. a, blue rhombi; b, red triangles; c, green circles; V, orange squares. c) Plot of the X-ray

powder diffraction patterns measured on [Ni(BPEB)] during heating-cooling cycles within the

range 50-210 °C. Heating step, red; cooling step, blue.

T, °C

5 10 15 20 25 2930

250

200

300

350

100

150

2θθθθ, deg

-2.0

-1.5

-1.0

-0.5

0

0.5

1.0

30 80 130 180 230 280

T, °C

(pT–p30)/p30%

▬ a ▬ b▬ c ▬ V

2θθθθ, deg

5 10 15 20 25 29

blue trace, 50 °C

red trace, 210 °C

(a)(b)

(c)

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Figure S6. a) Plot of the X-ray powder diffraction patterns measured on αααα-[Zn(BPEB)] as a

function of the temperature heating, with steps of 20 °C, up to decomposition. The permanent

porosity of species αααα-[Zn(BPEB)] can be appreciated. b) Percentage variation of the unit cell

parameters (pT) of αααα-[Zn(BPEB)] as a function of the temperature. The values at 30 °C (p30) have

been taken as the references. a, blue rhombi; b, red triangles; c, green circles; V, orange squares. c)

Plot of the X-ray powder diffraction patterns measured on αααα-[Zn(BPEB)] during heating-cooling

cycles within the range 50-210 °C. Heating step, red; cooling step, blue.

(a)(b)

(c)

2θ2θ2θ2θ , deg

4 8 12 16 20 23.5

blue trace, 50 °C

red trace, 210 °C

-2.0

-1.5

-1.0

-0.5

0

0.5

1.0

30 80 130 180 230 280 330

T, °C

4 8 12 16 20 23.5

30

410

190

110

270

350

T, °C

2θθθθ, deg

(pT–p30)/p30%

▬ a ▬ b▬ c ▬ V

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Figure S7. Schematic representation of the chemical transformation from two acetylenic groups

toward a tetrahedrane moiety.

Figure S8. a) Plot of the X-ray powder diffraction patterns measured on ββββ-[Zn(BPEB)] as a

function of the temperature heating, with steps of 20 °C, up to decomposition. The phase

transformation from ββββ-[Zn(BPEB)] to γγγγ-[Zn(BPEB)] can be appreciated from about 210 °C. b)

Percentage variation of the unit cell parameters (pT) of αααα-[Zn(BPEB)] as a function of the

temperature. The values at 30 °C (p30) have been taken as the references. a, blue rhombi; b, red

triangles; c, green circles; V, orange squares.

▬ a ▬ b▬ c ▬ V

T, C

(pT–p30)/p30%

(b)

-0,8

-0,6

-0,4

-0,2

0,0

0,2

0,4

0,6

30 90 150 210 270 3302θθθθ, deg

30

350

270

430

110

190

490

(a)

5 10 15 20 253

T, C

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Figure S9. Chemical stability of [Fe2(BPEB)3] upon exposure to water vapours at r.t., boiling

water, aqueous acidic (pH 6) or basic (pH 8) solutions at r.t. The peak indicated with a blue asterisk

in the pattern of the sample suspended in boiling water is the most intense Bragg reflection of the

H2BPEB ligand, witnessing progressive hydrolysis of the PCP during this harsh chemical treatment.

4 10 2015 24

2θθθθ , deg

pH 6, r.t., 8 h

As synthesized

pH 8, r.t., 8 h

Water, reflux, 8 h

Water vapors r.t., 120 h

*

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Figure S10. a) Chemical stability of αααα-[Zn(BPEB)] upon exposure to water vapours at r.t., boiling

water, aqueous acidic (pH 6) or basic (pH 8) solutions at r.t. In all of the cases, appearance of the β

phase is observed, as highlighted in b), where the progressive phase transition from αααα-[Zn(BPEB)]

to ββββ-[Zn(BPEB)] after 1, 5 and 8 hours in boiling water can be appreciated.

2θθθθ, deg4 10 2015

α-phase as synthesized

β-phase as synthesized

Water, reflux, 1 h

Water, reflux, 5 h

Water, boiling, 8 h

pH 6, r.t., 8 h

α-phase as synthesized

pH 8, r.t., 8 h

Water, reflux, 48 h

Water vapors, r.t., 120 h

2θθθθ, deg4 10 2015

(a)

(b)

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Figure S11. IAST selectivities of CO2 over N2 for 15:85 molar mixtures as determined from

adsorption isotherms at 298 and 273 K on [Fe2(BPEB)3] (dark grey), αααα-[Zn(BPEB)] (light grey)

and [Ni(BPEB)] (orange).

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Figure S12. Isoteric heat of adsorption for CO2 of [Fe2(BPEB)3] (dark grey), αααα-[Zn(BPEB)] (light

grey) and [Ni(BPEB)] (orange) using the Clausius-Clapeyron equation.

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Figure S13. N2 adsorption isotherms of [Fe2(BPEB)3] after the first activation treatment at 120 °C

under vacuum (blue diamonds) and after several activation/gas-adsorption cycles (blue circles).

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Figure S14. N2 adsorption isotherms of [Fe2(BPEB)3] and αααα-[Zn(BPEB)] after several

activation/gas-adsorption cycles.

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Figure S15. Fluorescence decay distribution obtained for the H2BPEB ligand (red dots, all panels)

compared with that observed for αααα-[Zn(BPEB)] (panel a, blue squares), [Fe2(BPEB)3] (panel b,

cyan stars), and [Ni(BPEB)] (panel c, magenta crosses). The corresponding best-fitting curves are

represented as solid lines of the same colors.

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Table S1. CH4 adsorption capacities of [Fe2(BPEB)3], [Ni(BPEB)] and αααα-[Zn(BPEB)] at 298 K,

273 K and 195 K.

T P Vads mads %wt V/V Qst

K bar cm3(STP)/g mmol/g kJ/mol

[Fe2(BPEB)3] 298 10 85.32 3.6 5.7 58.9 17

273 10 114.6 5.1 8.2 79.0

195 1a 170.0 7.6 12.1 117.3

[Ni(BPEB)] 298 10 38.9 1.6 2.6 20.6 18

273 10 62.2 2.8 4.4 33.0

195 1a 62.3 2.8 4.4 33.0

αααα- [Zn(BPEB)] 298 10 30.1 1.3 2.0 26.2 19

273 10 71.5 3.2 5.1 62.2

195 1a 68.9 3.1 5.0 59.9

a P/P0 is reported.

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Table S2. Fitting parameters for fluorescence decay time distributions. The reported values

represent the averages of the fitting parameters obtained on three experimental decays. The errors

are given by the corresponding standard deviations. Calculated mean fluorescence lifetime, τav, and

fluorescence quantum yield relative to αααα-[Zn(BPEB)]), Φfl.

Sample

ττττ1 [ps]

(f1)

ττττ2 [ps]

(f2)

ττττ3 [ps]

(f3)

ττττ4 [ps]

(f4)

ττττav [ps]

ΦΦΦΦfl

H2BPEB -

182±3

(0.34±0.02)

617±19

(0.46±0.02)

1670±50

(0.20±0.02)

679.7 0.509

(0.584)

αααα-[Zn(BPEB)] -

180±7

(0.32±0.02)

627±20

(0.49±0.02)

1710±60

(0.19±0.02)

689.7 1

[Fe2(BPEB)3] -

173±5

(0.29±0.01)

544±9

(0.50±0.01)

1714±22

(0.21±0.01)

682.1 0.024

[Ni(BPEB)]

20±1

(0.44±0.01)

143±3

(0.20±0.01)

525±10

(0.21±0.01)

1960±24

(0.15±0.01)

441.7 0.015