Angew. Chem. Int. Ed. 2012, 51, 1919 –1921s

Supporting Information

Wiley-VCH2012

69451Weinheim,Germany

Reversible Protonation of a Thiolate Ligand in an[Fe]-Hydrogenase Model Complex**

Dafa Chen,Rosario Scopelliti,and Xile Hu*

anie_201107634_sm_miscellaneous_information.pdf

Experimental Section

A. Chemicals and Reagents

All manipulations were carried out under an inert N2(g) atmosphere using a glovebox. Solvents were purified using a two-column solid-state purification system (Innovative Technology, NJ, USA) and transferred to the glove box without exposure to air. Deuterated solvents were purchased from Cambridge Isotope Laboratories, Inc., and were degassed and stored over activated 3 ? molecular sieves. All other reagents were purchased from commercial sources. Liquid compounds were degassed by standard freeze-pump-thaw procedures prior to use. Complex [(6-MeO-C5H3N-2-CH2CO)Fe(CO)2{S-(2,6-Me2C6H3)}] (1) was prepared as described previously.S1

B. Physical methods

The 1H and 13C NMR spectra were recorded on a Bruker Avance 400 spectrometer. 1H NMR chemical shifts were referenced to residual solvent as determined relative to Me4Si (δ = 0 ppm). The 13C{1H} chemical shifts were reported in ppm relative to the carbon resonance of CD3CN (1.3 and 118.3 ppm). IR spectra were recorded on a Varian 800 FT-IR spectrometer. Elemental analyses were performed on a Carlo Erba EA 1110 CHN instrument at EPFL. X-ray diffraction studies were carried out in the EPFL Crystallographic Facility. Data collection was performed at low temperature by a marresearch marμx system equipped with mar345 imaging plate scanner.Data were integrated and reduced by means of automar.S2 Solution, refinement and geometrical calculations for the crystal structure were performed by SHELXTL.S3

C. Synthetic methods

Synthesis of [(6-MeO-C5H3N-2-CH2CO)Fe(CO)2(CH3CN)2](BF4) (2)

HBF4·Et2O (34.5 mg, 0.213 mmol) was added into a solution of 1 (85.0 mg, 0.213 mmol) in CH3CN (1 mL) under stirring at room temperature. The color changed from red to yellow immediately. After 1 min, the solvent was evaporated. The solid residue was washed with Et2O (10 mL) and dried in vacuum. Compound 2 was isolated as a yellow solid in a quantitative yield (91.8 mg, 0.213 mmol).

1H NMR (400.13 MHz, CD

3CN, r.t.): 7.99 (t, J = 8.0 Hz, 1H), 7.20 (d, J = 8.0 Hz, 1H),

7.00 (d, J = 8.0 Hz, 1H), 4.69 (d, J = 20.0 Hz, 1H), 4.03 (s, 3H), 3.92 (d, J = 20.0 Hz, 1H), 1.96 (s, 6H) ppm. 1H NMR (400.13 MHz, CD3CN, -30 o C): 7.98 (t, J = 8.0 Hz, 1H), 7.19 (d, J = 8.0 Hz, 1H), 6.98 (d, J = 8.0 Hz, 1H), 4.72 (d, J = 20.0 Hz, 1H), 4.01 (s, 3H), 3.89 (d, J = 20.0 Hz, 1H), 1.96 (s, 6H) ppm. 13C NMR (100.62 MHz, CD3CN, -30 o C): 260.6 (CH2C O), 208.4 (terminal C O), 207.1 (terminal C O), 168.0, 161.2, 143.2, 118.6, 116.2, 105.7, 62.7, 57.1, 1.3 ppm. IR (νCO, cm-1): 2059 (s, terminal CO), 1997 (s, terminal CO), 1676 (s, acyl). Anal. Calcd for C14H14BF4FeN3O4: C, 39.0; H, 3.3; N, 9.8. Found: C, 39.5; H, 3.3, N, 9.3. Synthesis of [(6-MeO-C5H3N-2-CH2CO)Fe(CO)2(CH3CN)(C6H5N)](BF4) (3) Route A: Pyridinium tetrafluoroborate (PyH·BF4, 25.4 mg, 0.152 mmol) was added into a solution of 1 (60.7 mg, 0.152 mmol) in CH3CN (1 mL) under stirring at room temperature. The color of the solution changed from red to yellow immediately. After 1 min, the solvent was evaporated. The solid residue was washed with Et2O (10 mL) and dried in vacuum to

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give 3 as a yellow solid (65.0 mg, 0.139 mmol; yield: 91%). Single crystals suitable for X-ray diffraction study were obtained by diffusion of a mixture of ether and pentane into a solution of 3 in CH3CN.

Route B: Pyridine (6.9 mg, 0.0873 mmol) was added into a solution of 2 (37.5 mg, 0.0870 mmol) in CH3CN (1 mL) under stirring at room temperature. After 1 min, the solvent was evaporated. The solid residue was washed with Et2O (10 mL) and dried in vacuum to give 3 as a yellow solid (37.0 mg, 0.0789 mmol; yield: 91%).

1H NMR (400.13 MHz, CD

CN, r.t.): 8.35 (d, J = 4.4 Hz, 2H), 7.95 (m, 2H), 7.44 (t, J =

3

6.0 Hz, 2H),

7.08 (d, J =

8.0 Hz, 1H), 6.99 (d, J = 8.0 Hz, 1H), 4.12 (s, 3H), 3.84 (d, J = 20.0 Hz, 1H), 3.72 (d, J = 20.0 Hz, 1H), 1.96 (s, 3H) ppm. 1H NMR (400.13 MHz, CD3CN, -30 o C): 8.32 (d, J = 4.4 Hz, 2H), 7.94 (m, 2H), 7.43 (t, J = 6.0 Hz, 2H), 7.07 (d, J = 8.0 Hz, 1H), 6.96 (d, J = 8.0 Hz, 1H), 4.10 (s, 3H), 3.79 (d, J = 20.0 Hz, 1H), 3.70 (d, J = 20.0 Hz, 1H),

1.96 (s, 3H) ppm. 13C NMR (100.62 MHz, CD3CN, -30 o C): 266.5 (CH2C O), 208.8 (terminal

C O), 208.7 (terminal C O), 168.1, 161.0, 153.7, 143.3, 140.3, 127.1, 118.5, 115.9, 106.3, 61.9,

57.2, 1.3 ppm. IR (νCO, cm-1): 2042 (s, terminal CO), 1979 (s, terminal CO), 1663 (s, acyl). Anal. Calcd for C17H16BF4FeN3O4: C, 43.5; H, 3.4; N, 9.0. Found: C, 43.2; H, 3.5, N, 8.5.

Reaction of 2 with HS(2,6-Me2C6H3) in presence of NEt3

NEt3 (9.4 mg, 0.0930 mmol) was added into a mixture of 2 (40.0 mg, 0.0928 mmol) and HS(2,6-Me2C6H3) (12.8 mg, 0.0928 mmol) in CH3CN (1 mL). The color of the solution changed from yellow to red immediately. After 1 min, the solvent was evaporated in vacuum. The residue was extracted with Et2O (10 mL). After filtration, the filtrate was dried in vacuum in the dark to give 1 (35.5 mg, 0.0890 mmol; yield: 96%).

Reaction of 3 with HS(2,6-Me2C6H3) in presence of NEt3

NEt3 (9.3 mg, 0.0921 mmol) was added into a mixture of 3 (43.0 mg, 0.0917 mmol) and HS(2,6-Me2C6H3) (12.7 mg, 0.0920 mmol) in CH3CN (1 mL). The color of the solution changed from yellow to red immediately. After 1 min, the solvent was evaporated in vacuum. The residue was extracted with Et2O (10 mL). After filtration, the filtrate was dried in vacuum in the dark to give 1 (30.0 mg, 0.0752 mmol; yield: 82%).

Reaction of 2 with NaS(2,6-Me2C6H3)

NaS(2,6-Me2C6H3) (11.2 mg, 0.0700 mmol) was added into a solution of 2 (30.0 mg, 0.0696 mmol) in CH3CN (1 mL). The color of the solution changed from yellow to red immediately. After 1 min, the solvent was evaporated in vacuum. The residue was extracted with Et2O (10 mL). After filtration, the filtrate was dried in vacuum in the dark to give 1 (22.0 mg, 0.0551 mmol; yield: 79%).

D. Crystallographic Details for 3

A total of 6247 reflections (-16 < h < 16, -11 < k < 11, -13 < l < 13) were collected at T = 140(2) K in the range of 2.54 to 24.54o of which 6247 were unique (R int = 0.0000); Mo Kαradiation (λ= 0.71073 ?). The structure was solved by the Direct method. All non-hydrogen atoms were refined anisotropically, and hydrogen atoms were placed in calculated idealized positions. The residual peak and hole electron densities were 1.002 and –0.366 eA-3,

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respectively. The absorption coefficient was 0.822 mm-1. The least squares refinement

converged normally with residuals of R(F) = 0.0604, wR(F2) = 0.1460 and a GOF = 1.008 (I>2σ(I)). C17H16BF4FeN3O4, Mw = 468.99, space group Pna21, Orthorhombic, a = 14.198(4), b = 9.710(3), c = 28.917(7) ?, V = 3986.6(19) ?3, Z = 8, ρcalcd = 1.563 Mg/m3. CCDC 851252 contains the supplementary crystallographic data for this paper. These data can be obtained

free of charge from The Cambridge Crystallographic Data Centre via

https://www.360docs.net/doc/3a10695169.html,/data_request/cif.

References

(S1) Chen, D. F.; Scopelliti, R.; Hu, X. L. Angew. Chem. Int. Ed.2011, 50, 5671-5673.

(S2) Automar, release 2.8.0, Marresearch GmbH, Germany, 2011.

(S3) Sheldrick, G. M. SHELXTL release 6.1.4 ed.; Bruker AXS Inc.: Madison, Wisconsin,

53719, USA, 2003.

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S4 IR spectra

Figure S1. IR spectrum of 2 in the solid state.

Figure S2. IR spectrum of 3 in the solid state.

NMR spectra

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Figure S4. 1H NMR spectrum of 2 in CD3CN at -30 o C.

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Figure S5. 13C NMR spectrum of 2 in CD 3CN at -30 o C.

Figure S6. 1H NMR spectrum of 3 in CD3CN at room temperature.

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Figure S7. 1H NMR spectrum of 3 in CD3CN at -30 o C.

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Figure S8. 13C NMR spectrum of 3 in CD3CN at -30 o C.

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