Supporting Information

© Copyright Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 2008

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AND/NOT Sensing of Fluoride and Cyanide by Ferrocene Derivatized

Lewis Acids

Alexander E Broomsgrove,[a] David A. Addy,[a] Christopher Bresner,[b] Ian A. Fallis,[b]

Amber L. Thompson[a] and Simon Aldridge.[a]*

[a] Inorganic Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK;

[b] Cardiff School of Chemistry, Main Building, Park Place, Cardiff, CF10 3AT, UK.

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Supporting Information (15 pages)

1. Crystallographic data for 1a 2

2. Binding constant determination for 1a with fluoride 10

3. Binding constant determination for 1a with cyanide 11

4. Electrospray mass spectra of [1a.CN]- and [1b.CN]- 12

5. Synthetic and characterizing data for Fc*BMes2 (1b) 14

6. Synthetic and characterizing data for [nBu4N]+[Fc*BMes2.CN]- i.e. [nBu4N]+[1b.CN]- 15

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1. Crystallographic data for 1a Table 1. Crystal data and structure refinement details.

Empirical formula C28H31BFe CCDC deposit number 671665 Formula weight 434.19 Temperature 120(2) K Wavelength 0.71073 Å Crystal system Monoclinic Space group P21/n Unit cell dimensions a = 10.2980(4) Å α = 90° b = 15.7275(8) Å β = 104.958(3)° c = 14.0269(5) Å γ = 90° Volume 2194.84(16) Å3 Z 4 Density (calculated) 1.314 Mg / m3 Absorption coefficient 0.699 mm−1 F(000) 920 Crystal Plate; Red Crystal size 0.08 × 0.06 × 0.01 mm3 θ range for data collection 2.99 − 25.03° Index ranges −12 ≤ h ≤ 12, −18 ≤ k ≤ 18, −16 ≤ l ≤ 16 Reflections collected 22801 Independent reflections 3855 [Rint = 0.1177] Completeness to θ = 25.03° 99.7 % Absorption correction Semi−empirical from equivalents Max. and min. transmission 0.9930 and 0.9462 Refinement method Full-matrix least-squares on F2 Data / restraints / parameters 3855 / 0 / 277 Goodness-of-fit on F2 1.094 Final R indices [F2 > 2σ(F2)] R1 = 0.0658, wR2 = 0.1190 R indices (all data) R1 = 0.1189, wR2 = 0.1463 Largest diff. peak and hole 0.413 and −0.421 e Å−3

Diffractometer: Bruker-Nonius APEX II CCD camera (φ scans and ω scans to fill asymmetric unit). Cell determination: DirAx (Duisenberg, A.J.M.(1992). J. Appl. Cryst. 25, 92-96.) Data collection: Collect (Collect: Data collection software, R. Hooft, Nonius B.V., 1998). Data reduction and cell refinement: Denzo (Z. Otwinowski & W. Minor, Methods in Enzymology (1997) Vol. 276: Macromolecular Crystallography, part A, pp. 307−326; C. W. Carter, Jr. & R. M. Sweet, Eds., Academic Press). Absorption correction: Sheldrick, G. M. SADABS 2007/2 - Bruker Nonius area detector scaling and absorption correction. Structure solution: Sir2004 (Burla, M.C., Caliandro, R., Carrozzini, B., Cascarano, G., De Caro, L., Giacovazzo, C. & Polidori, G. (2004). J. Appl. Cryst. 37, 258). Structure refinement: SHELXL97 (Sheldrick, G. M. (1997). University of Göttingen, Germany). Graphics: PLATON/PLUTON (Spek, A. L. (1990). Acta Cryst. A46, C34). Special details: The hydrogen atoms were fixed as riding models.

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Table 2. Atomic coordinates [× 104], equivalent isotropic displacement parameters [Å2 × 103] and site occupancy factors. Ueq is defined as one third of the trace of the orthogonalized Uij tensor.

Atom x y z Ueq S.o.f.

C1 2884(4) 1381(3) 1586(3) 24(1) 1 C2 3023(5) 2225(3) 2011(4) 29(1) 1 C3 3393(5) 2802(3) 1367(4) 37(1) 1 C4 3525(5) 2341(4) 528(4) 38(1) 1 C5 3233(5) 1477(4) 661(4) 31(1) 1 C6 6286(5) 1102(3) 2615(4) 32(1) 1 C7 6189(5) 1858(4) 3145(4) 32(1) 1 C8 6442(5) 2547(3) 2574(4) 31(1) 1 C9 6678(5) 2224(3) 1687(4) 29(1) 1 C10 6593(5) 1323(3) 1727(4) 28(1) 1 C11 2129(4) 630(3) 3092(3) 23(1) 1 C12 1204(5) 1183(3) 3356(3) 25(1) 1 C13 1005(5) 1146(3) 4304(4) 28(1) 1 C14 1687(5) 586(3) 5018(3) 27(1) 1 C15 2630(5) 55(3) 4764(3) 28(1) 1 C16 2861(5) 69(3) 3832(3) 24(1) 1 C17 327(4) 1804(3) 2644(3) 29(1) 1 C18 1459(5) 554(4) 6037(4) 35(1) 1 C19 3929(5) −508(3) 3630(4) 30(1) 1 C20 1996(5) −273(3) 1412(3) 23(1) 1 C21 651(5) −576(3) 1194(3) 24(1) 1 C22 283(5) −1328(3) 699(3) 24(1) 1 C23 1190(4) −1859(3) 410(3) 23(1) 1 C24 2517(5) −1569(3) 605(3) 25(1) 1 C25 2914(5) −795(3) 1081(3) 25(1) 1 C26 −463(5) −64(3) 1450(4) 29(1) 1 C27 772(5) −2690(3) −88(4) 28(1) 1 C28 4387(5) −572(3) 1247(4) 30(1) 1 Fe1 4813(1) 1880(1) 1793(1) 25(1) 1 B1 2384(5) 584(4) 2029(4) 23(1) 1

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Table 3. Bond lengths [Å] and angles [°].

C1−C5 1.441(7) C1−C2 1.447(7) C1−B1 1.546(7) C1−Fe1 2.085(5) C2−C3 1.401(7) C2−Fe1 2.019(5) C2−H2 0.9500 C3−C4 1.417(8) C3−Fe1 2.037(5) C3−H3 0.9500 C4−C5 1.414(7) C4−Fe1 2.054(5) C4−H4 0.9500 C5−Fe1 2.058(5) C5−H5 0.9500 C6−C10 1.405(7) C6−C7 1.420(7) C6−Fe1 2.055(5) C6−H6 0.9500 C7−C8 1.410(7) C7−Fe1 2.053(5) C7−H7 0.9500 C8−C9 1.423(7) C8−Fe1 2.041(5) C8−H8 0.9500 C9−C10 1.422(7) C9−Fe1 2.038(5) C9−H9 0.9500 C10−Fe1 2.056(5) C10−H10 0.9500 C11−C12 1.408(7) C11−C16 1.420(6) C11−B1 1.581(7) C12−C13 1.398(7) C12−C17 1.517(6) C13−C14 1.382(7) C13−H13 0.9500 C14−C15 1.394(7) C14−C18 1.507(7) C15−C16 1.388(7) C15−H15 0.9500 C16−C19 1.509(7) C17−H17A 0.9800 C17−H17B 0.9800 C17−H17C 0.9800 C18−H18A 0.9800 C18−H18B 0.9800 C18−H18C 0.9800 C19−H19A 0.9800 C19−H19B 0.9800 C19−H19C 0.9800 C20−C21 1.421(6) C20−C25 1.417(7) C20−B1 1.597(7) C21−C22 1.375(7) C21−C26 1.518(7) C22−C23 1.388(7) C22−H22 0.9500 C23−C24 1.400(6) C23−C27 1.492(6)

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C24−C25 1.398(7) C24−H24 0.9500 C25−C28 1.515(6) C26−H26A 0.9800 C26−H26B 0.9800 C26−H26C 0.9800 C27−H27A 0.9800 C27−H27B 0.9800 C27−H27C 0.9800 C28−H28A 0.9800 C28−H28B 0.9800 C28−H28C 0.9800 C5−C1−C2 104.7(4) C5−C1−B1 129.3(5) C2−C1−B1 125.9(4) C5−C1−Fe1 68.7(3) C2−C1−Fe1 66.9(3) B1−C1−Fe1 130.8(3) C3−C2−C1 110.0(5) C3−C2−Fe1 70.5(3) C1−C2−Fe1 71.8(3) C3−C2−H2 125.0 C1−C2−H2 125.0 Fe1−C2−H2 124.3 C2−C3−C4 107.7(5) C2−C3−Fe1 69.1(3) C4−C3−Fe1 70.4(3) C2−C3−H3 126.1 C4−C3−H3 126.1 Fe1−C3−H3 125.9 C3−C4−C5 108.2(5) C3−C4−Fe1 69.1(3) C5−C4−Fe1 70.0(3) C3−C4−H4 125.9 C5−C4−H4 125.9 Fe1−C4−H4 126.6 C4−C5−C1 109.3(5) C4−C5−Fe1 69.7(3) C1−C5−Fe1 70.6(3) C4−C5−H5 125.4 C1−C5−H5 125.4 Fe1−C5−H5 125.9 C10−C6−C7 108.6(5) C10−C6−Fe1 70.0(3) C7−C6−Fe1 69.7(3) C10−C6−H6 125.7 C7−C6−H6 125.7 Fe1−C6−H6 126.1 C8−C7−C6 107.4(4) C8−C7−Fe1 69.4(3) C6−C7−Fe1 69.9(3) C8−C7−H7 126.3 C6−C7−H7 126.3 Fe1−C7−H7 126.0 C7−C8−C9 108.6(5) C7−C8−Fe1 70.3(3) C9−C8−Fe1 69.4(3) C7−C8−H8 125.7 C9−C8−H8 125.7 Fe1−C8−H8 126.1 C8−C9−C10 107.2(5) C8−C9−Fe1 69.7(3) C10−C9−Fe1 70.4(3) C8−C9−H9 126.4 C10−C9−H9 126.4

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Fe1−C9−H9 125.1 C6−C10−C9 108.1(5) C6−C10−Fe1 70.0(3) C9−C10−Fe1 69.0(3) C6−C10−H10 125.9 C9−C10−H10 125.9 Fe1−C10−H10 126.6 C12−C11−C16 117.3(4) C12−C11−B1 124.3(4) C16−C11−B1 118.3(4) C13−C12−C11 119.9(4) C13−C12−C17 116.4(4) C11−C12−C17 123.6(4) C14−C13−C12 123.0(5) C14−C13−H13 118.5 C12−C13−H13 118.5 C13−C14−C15 116.9(5) C13−C14−C18 122.2(5) C15−C14−C18 120.8(4) C16−C15−C14 122.1(4) C16−C15−H15 119.0 C14−C15−H15 119.0 C15−C16−C11 120.7(5) C15−C16−C19 118.5(4) C11−C16−C19 120.8(4) C12−C17−H17A 109.5 C12−C17−H17B 109.5 H17A−C17−H17B 109.5 C12−C17−H17C 109.5 H17A−C17−H17C 109.5 H17B−C17−H17C 109.5 C14−C18−H18A 109.5 C14−C18−H18B 109.5 H18A−C18−H18B 109.5 C14−C18−H18C 109.5 H18A−C18−H18C 109.5 H18B−C18−H18C 109.5 C16−C19−H19A 109.5 C16−C19−H19B 109.5 H19A−C19−H19B 109.5 C16−C19−H19C 109.5 H19A−C19−H19C 109.5 H19B−C19−H19C 109.5 C21−C20−C25 115.5(4) C21−C20−B1 119.6(4) C25−C20−B1 124.9(4) C22−C21−C20 121.5(4) C22−C21−C26 116.7(4) C20−C21−C26 121.7(4) C21−C22−C23 123.2(4) C21−C22−H22 118.4 C23−C22−H22 118.4 C22−C23−C24 116.3(4) C22−C23−C27 121.9(4) C24−C23−C27 121.8(4) C25−C24−C23 121.9(5) C25−C24−H24 119.0 C23−C24−H24 119.0 C24−C25−C20 121.5(4) C24−C25−C28 115.7(4) C20−C25−C28 122.8(4) C21−C26−H26A 109.5 C21−C26−H26B 109.5 H26A−C26−H26B 109.5 C21−C26−H26C 109.5

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H26A−C26−H26C 109.5 H26B−C26−H26C 109.5 C23−C27−H27A 109.5 C23−C27−H27B 109.5 H27A−C27−H27B 109.5 C23−C27−H27C 109.5 H27A−C27−H27C 109.5 H27B−C27−H27C 109.5 C25−C28−H28A 109.5 C25−C28−H28B 109.5 H28A−C28−H28B 109.5 C25−C28−H28C 109.5 H28A−C28−H28C 109.5 H28B−C28−H28C 109.5 C2−Fe1−C3 40.4(2) C2−Fe1−C9 148.7(2) C3−Fe1−C9 114.1(2) C2−Fe1−C8 115.9(2) C3−Fe1−C8 102.7(2) C9−Fe1−C8 40.8(2) C2−Fe1−C7 107.7(2) C3−Fe1−C7 123.7(2) C9−Fe1−C7 68.4(2) C8−Fe1−C7 40.3(2) C2−Fe1−C6 130.2(2) C3−Fe1−C6 163.5(2) C9−Fe1−C6 68.0(2) C8−Fe1−C6 67.7(2) C7−Fe1−C6 40.4(2) C2−Fe1−C4 68.0(2) C3−Fe1−C4 40.5(2) C9−Fe1−C4 104.7(2) C8−Fe1−C4 122.7(2) C7−Fe1−C4 160.3(2) C6−Fe1−C4 155.9(2) C2−Fe1−C10 168.9(2) C3−Fe1−C10 150.6(2) C9−Fe1−C10 40.6(2) C8−Fe1−C10 68.0(2) C7−Fe1−C10 67.9(2) C6−Fe1−C10 40.0(2) C4−Fe1−C10 119.7(2) C2−Fe1−C5 68.2(2) C3−Fe1−C5 68.1(2) C9−Fe1−C5 126.7(2) C8−Fe1−C5 161.6(2) C7−Fe1−C5 158.0(2) C6−Fe1−C5 124.9(2) C4−Fe1−C5 40.2(2) C10−Fe1−C5 111.8(2) C2−Fe1−C1 41.25(19) C3−Fe1−C1 69.0(2) C9−Fe1−C1 166.36(19) C8−Fe1−C1 152.8(2) C7−Fe1−C1 121.89(19) C6−Fe1−C1 113.1(2) C4−Fe1−C1 68.5(2) C10−Fe1−C1 131.46(19) C5−Fe1−C1 40.69(19) C1−B1−C11 119.7(4) C1−B1−C20 122.0(4) C11−B1−C20 118.1(4)

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Table 4. Anisotropic displacement parameters [Å2× 103]. The anisotropic displacement factor exponent takes the form: −2π 2[h2a*2U11 + ... + 2 h k a* b* U12 ].

Atom U11 U22 U33 U23 U13 U12

C1 18(2) 29(3) 23(3) 1(2) 1(2) 0(2) C2 22(3) 25(3) 41(3) 1(2) 10(2) 4(2) C3 23(3) 25(3) 61(4) 17(3) 7(3) 5(2) C4 21(3) 48(4) 40(3) 21(3) −3(2) −2(2) C5 18(3) 43(3) 28(3) 1(2) −2(2) −3(2) C6 24(3) 31(3) 35(3) 2(2) −6(2) 0(2) C7 24(3) 45(3) 25(3) −5(3) 4(2) −3(2) C8 26(3) 30(3) 35(3) −6(2) 4(2) −5(2) C9 18(3) 40(3) 31(3) −4(2) 7(2) −4(2) C10 21(3) 29(3) 30(3) −5(2) 3(2) 2(2) C11 22(2) 16(2) 26(3) −2(2) 0(2) −4(2) C12 24(3) 22(3) 26(3) −2(2) 2(2) −3(2) C13 25(3) 27(3) 33(3) −5(2) 9(2) −4(2) C14 26(3) 28(3) 26(3) −2(2) 5(2) −4(2) C15 32(3) 25(3) 22(3) 3(2) 1(2) −2(2) C16 19(2) 20(3) 32(3) −4(2) 3(2) −6(2) C17 22(2) 28(3) 35(3) 0(2) 4(2) 1(2) C18 41(3) 39(3) 28(3) −2(2) 13(2) 3(3) C19 32(3) 23(3) 30(3) 3(2) 2(2) −1(2) C20 22(3) 24(3) 23(2) −1(2) 4(2) 2(2) C21 25(3) 27(3) 19(2) 4(2) 2(2) 5(2) C22 21(2) 26(3) 22(2) 3(2) 2(2) −3(2) C23 27(2) 23(3) 17(2) 5(2) 0(2) −3(2) C24 29(3) 21(3) 24(2) 0(2) 7(2) 4(2) C25 22(2) 29(3) 22(2) 2(2) 2(2) −4(2) C26 21(3) 33(3) 31(3) −2(2) 2(2) 1(2) C27 31(3) 22(3) 29(3) −5(2) 2(2) 0(2) C28 31(3) 24(3) 34(3) −3(2) 8(2) 3(2) Fe1 21(1) 24(1) 29(1) 2(1) 3(1) −1(1) B1 15(3) 27(3) 25(3) 1(2) 1(2) 2(2)

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Table 5. Hydrogen coordinates [× 104] and isotropic displacement parameters [Å2 × 103].

Atom x y z Ueq S.o.f.

H2 2884 2368 2635 35 1 H3 3531 3396 1472 45 1 H4 3768 2573 −27 46 1 H5 3261 1031 211 38 1 H6 6164 540 2825 39 1 H7 5991 1894 3768 38 1 H8 6452 3131 2753 37 1 H9 6859 2549 1165 35 1 H10 6721 937 1238 33 1 H13 373 1523 4465 34 1 H15 3130 −328 5244 33 1 H17A −619 1698 2616 43 1 H17B 472 1730 1986 43 1 H17C 563 2387 2871 43 1 H18A 2231 808 6511 53 1 H18B 1355 −38 6219 53 1 H18C 643 873 6041 53 1 H19A 4496 −722 4256 45 1 H19B 4483 −190 3281 45 1 H19C 3500 −988 3222 45 1 H22 −635 −1493 547 28 1 H24 3167 −1908 409 30 1 H26A −1324 −355 1194 44 1 H26B −504 502 1152 44 1 H26C −280 −10 2168 44 1 H27A 1084 −3154 382 43 1 H27B 1168 −2752 −649 43 1 H27C −210 −2710 −323 43 1 H28A 4925 −924 1781 44 1 H28B 4523 30 1429 44 1 H28C 4666 −676 640 44 1

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2. Binding constant determination for 1a with fluoride in dichloromethane Binding constants were determined using the method reported by Gabbai (S. Solé, F.P. Gabbaï, Chem. Commun. 2004, 1284-1285), using the program LabFit (www.labfit.net). Experimental data of Abs/Abso vs. [F-] were fitted to the expression Abs/Abso = Y = (0.5/A)*(A – X – 1/B + [(A + X + 1/B)**2 – 4*A*X)**0.5 Where X = [F-], A = [FcBMes2]o and B = KF associated with the reaction: FcBMes2 + F- FcBMes2F- i.e. KF = [FcBMes2F-]/[FcBMes2][F-] The graph shows experimental data (points) and the best-fit line obtained using the above expression (A = 5.5 x 10-4, B = 7.8 x 104, R2 = 0.9987). Hence KF = 7.8(1.2) x 104 mol-1 dm3.

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3. Binding constant determination for 1a with cyanide in dichloromethane The binding constant of 1a for cyanide in dichloromethane (KCN) was evaluated in an analogous manner to KF (above) FcBMes2 + CN- FcBMes2CN- KCN = [FcBMes2CN-]/[FcBMes2][CN-] The graph shows experimental data (points) and the best-fit line obtained using the above expression (A = 6.0 x 10-4, B = 8.3 x 104, R2 = 0.9960). Hence KCN = 8.3(2.0) x 104 mol-1 dm3.

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4. Electrospray mass spectra of [1a.CN]- and [1b.CN]-

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15

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5. Synthetic and characterizing data for Fc*BMes2 (1b) To a solution of mesityllithium (0.313 g, 2.48 mmol) in diethyl ether (ca. 35 mL) was added Fc*BBr2 (0.42 equiv.) also in diethyl ether (ca. 30 mL) and the reaction mixture stirred for 18 h, at which point the reaction was judged to be complete by 11B NMR spectroscopy (quantitative conversion to a single resonance at δB 77.1). After removal of volatiles in vacuo, extraction into hexanes (ca. 20 mL) and cooling to -30oC, 1b was obtained as a purple powder (yield: 0.226 g, 44 %). 1H NMR (300 MHz, [D1]chloroform, 20oC): δ 1.66 (s, 15H, CH3 of Cp*), 2.19 (s, 6H, para-CH3 of Mes), 2.30 (s, 12H, ortho-CH3 of Mes), 4.05 (m, 2H, CH of C5H4), 4.15 (m, 2H, CH of C5H4), 6.70 (s, 4H, CH of Mes). 13C NMR (126 MHz, [D6]benzene, 20oC): 11.6 (CH3 of Cp*), 21.3 (para-CH3 of Mes), 25.0 (ortho-CH3 of Mes), 79.9 (quaternary of Cp*), 81.0, 82.1 (C5H4), 128.2 (aromatic CH of Mes), 136.9 (para-quaternary of Mes), 139.1 (ortho-quaternary of Mes), boron-bound quaternary carbons not observed. 11B (96 MHz, [D6]benzene, 20oC): 77.1. MS(EI): M+ = 504.2 (100 %), exact mass (calc. for 10B isotopomer) 503.2682, (obs.) 503.2677. UV/Vis (CH3CN): λmax = 542 nm, ε = 1420 mol-1 cm-1 dm3. E1/2 vs. FcH/FcH+ (peak-to-peak separation) = -176 (75) mV in CH3CN.

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6. Synthetic and characterizing data for [nBu4N]+[Fc*BMes2.CN]- i.e. [nBu4N]+[1b.CN]-

A mixture of 1b (0.05 g, 0.10 mmol) and tetra-n-butylammonium cyanide dihydrate (1.05 equiv) in [D]chloroform (5 mL) was stirred for 1 h after which time the reaction was deemed complete by 11B NMR spectroscopy quantitative conversion to a single resonance at δB -16.8). Concentration of the reaction mixture and layering with diethylether led to the formation of [nBu4N]+[1b.CN]- as orange microcrystals (yield: 0.081 g, 91 %). 1H NMR (300 MHz, [D]chloroform, 20oC): d 0.96 (m, 12H, CH3 of [nBu4N]+), 1.34 (m, 8H, CH2 of [nBu4N]+), 1.47 (m, 8H, CH2 of [nBu4N]+), 1.75 (s, 15 H, Cp*), 1.95 (s, 6H, para-CH3 of Mes), 2.06 (s, 12H, ortho-CH3 of Mes), 2.94 (m, 8H, NCH2 of [nBu4N]+), 3.52 (s, 2H, CH of C5H4), 3.68 (s, 2H, CH of C5H4), 6.43 (s, 4H, aromatic CH of Mes). 13C NMR (126 MHz, [D6]benzene, 20oC): 15.5 (CH3 of Cp*), 17.4 (CH3 of [nBu4N]+), 23.4, 27.5 (CH2 of [nBu4N]+), 24.7 (para-CH3 of Mes), 30.0 (br, ortho-CH3 of Mes), 61.6 (NCH2 of [nBu4N]+), 76.0, 81.2 (C5H4), 82.0 (quaternary of Cp*), 133.2 (aromatic CH of Mes), 134.6 (para-quaternary of Mes), 146.0 (ortho-quaternary of Mes), 175.6 (CN-), boron-bound quaternary carbons not observed. 11B (96 MHz, [D]chloroform, 20oC): -16.8. MS(ES neg): [1b.CN]- = 530.4 (100 %), exact mass (calc. for 56Fe, 10B isotopomer) 529.2723, (obs.) 529.2730. UV/Vis (CH3CN): λmax = 481 nm, ε = 295 mol-1 cm-1 dm3. IR (CHCl3): 2162 cm-1 st, ν(CN). E1/2 vs. FcH/FcH+ (peak-to-peak separation) = -691 (95) mV in CH3CN.