Abstract
The dicyanodicarbonyliron(II) thiolate complexes trans, cis-[(CN)2(CO)2Fe(S,S-C-R)]- (R = OEt (2), N(Et)2 (3)) were prepared by the reaction of [Na][S-C(S)-R] and [Fe(CN)2(CO)3(Br)]- (1). Complex 1 was obtained from oxidative addition of cyanogen bromide to [Fe(CN)(CO)4]-. In a similar fashion, reaction of complex 1 with [Na][S,O-C5H4N], and [Na][S,N-C5H4] produced the six-coordinate trans,cis-[(CN)2-(CO)2Fe (S,O-C5H4N)]- (6) and trans,cis-[(CN)2 (CO)2Fe(S,N-C5H4)]- (7) individually. Photolysis of tetrahydrofuran (THF) solution of complexes 2, 3, and 7 under CO led to formation of the coordinatively unsaturated iron(II) dicyanocarbonyl thiolate compounds [(CN)2(CO)Fe(S,S-C-R)]- (R = OEt (4), N(Et)2 (5)) and [(CN)2(CO)Fe(S,N-C5H4)]- (8), respectively. The IR νCN stretching frequencies and patterns of complexes 4, 5, and 8 have unambiguously identified two CN- ligands occupying cis positions. In addition, density functional theory calculations suggest that the architecture of five-coordinate complexes 4, 5, and 8 with a vacant site trans to the CO ligand and two CN- ligands occupying cis positions serves as a conformational preference. Complexes 2, 3, and 7 were reobtained when the THF solution of complexes 4, 5, and 8 were exposed to CO atmosphere at 25 °C individually. Obviously, CO ligand can be reversibly bound to the FeII site in these model compounds. Isotopic shift experiments demonstrated the lability of carbonyl ligands of complexes 2, 3, 4, 5, 7, and 8. Complexes [(CN)2(CO)Fe(S,S-C-R)]- and NiA/NiC states [NiFe] hydrogenases from D. gigas exhibit a similar one-band pattern in the νCO region and two-band pattern in the νCN region individually, but in different positions, which may be accounted for by the distinct electronic effects betwen [S,S-C-R]- and cysteine ligands. Also, the facile formations of five-coordinate complexes 4, 5, and 8 imply that the strong σ-donor, weak π-acceptor CN- ligands play a key role in creating/stabilizing five-coordinate iron(II) [(CN)2(CO)Fe(S,S-C-R)]- complexes with a vacant coordination site trans to the CO ligand.
| Original language | English |
|---|---|
| Pages (from-to) | 1680-1688 |
| Number of pages | 9 |
| Journal | Journal of the American Chemical Society |
| Volume | 124 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2002 Feb 27 |
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All Science Journal Classification (ASJC) codes
- Catalysis
- Chemistry(all)
- Biochemistry
- Colloid and Surface Chemistry
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Six-coordinate and five-coordinate FeII(CN)2(CO)x thiolate complexes (x = 1, 2) : Synthetic advances for iron sites of [NiFe] hydrogenases. / Liaw, Wen Feng; Lee, Jiun Hung; Gau, Hung Bin; Chen, Chien Hong; Jung, Shiou Ju; Hung, Chen Hsiung; Chen, Wen Yuan; Hu, Ching-Han; Lee, Gene Hsiang.
In: Journal of the American Chemical Society, Vol. 124, No. 8, 27.02.2002, p. 1680-1688.Research output: Contribution to journal › Article
TY - JOUR
T1 - Six-coordinate and five-coordinate FeII(CN)2(CO)x thiolate complexes (x = 1, 2)
T2 - Synthetic advances for iron sites of [NiFe] hydrogenases
AU - Liaw, Wen Feng
AU - Lee, Jiun Hung
AU - Gau, Hung Bin
AU - Chen, Chien Hong
AU - Jung, Shiou Ju
AU - Hung, Chen Hsiung
AU - Chen, Wen Yuan
AU - Hu, Ching-Han
AU - Lee, Gene Hsiang
PY - 2002/2/27
Y1 - 2002/2/27
N2 - The dicyanodicarbonyliron(II) thiolate complexes trans, cis-[(CN)2(CO)2Fe(S,S-C-R)]- (R = OEt (2), N(Et)2 (3)) were prepared by the reaction of [Na][S-C(S)-R] and [Fe(CN)2(CO)3(Br)]- (1). Complex 1 was obtained from oxidative addition of cyanogen bromide to [Fe(CN)(CO)4]-. In a similar fashion, reaction of complex 1 with [Na][S,O-C5H4N], and [Na][S,N-C5H4] produced the six-coordinate trans,cis-[(CN)2-(CO)2Fe (S,O-C5H4N)]- (6) and trans,cis-[(CN)2 (CO)2Fe(S,N-C5H4)]- (7) individually. Photolysis of tetrahydrofuran (THF) solution of complexes 2, 3, and 7 under CO led to formation of the coordinatively unsaturated iron(II) dicyanocarbonyl thiolate compounds [(CN)2(CO)Fe(S,S-C-R)]- (R = OEt (4), N(Et)2 (5)) and [(CN)2(CO)Fe(S,N-C5H4)]- (8), respectively. The IR νCN stretching frequencies and patterns of complexes 4, 5, and 8 have unambiguously identified two CN- ligands occupying cis positions. In addition, density functional theory calculations suggest that the architecture of five-coordinate complexes 4, 5, and 8 with a vacant site trans to the CO ligand and two CN- ligands occupying cis positions serves as a conformational preference. Complexes 2, 3, and 7 were reobtained when the THF solution of complexes 4, 5, and 8 were exposed to CO atmosphere at 25 °C individually. Obviously, CO ligand can be reversibly bound to the FeII site in these model compounds. Isotopic shift experiments demonstrated the lability of carbonyl ligands of complexes 2, 3, 4, 5, 7, and 8. Complexes [(CN)2(CO)Fe(S,S-C-R)]- and NiA/NiC states [NiFe] hydrogenases from D. gigas exhibit a similar one-band pattern in the νCO region and two-band pattern in the νCN region individually, but in different positions, which may be accounted for by the distinct electronic effects betwen [S,S-C-R]- and cysteine ligands. Also, the facile formations of five-coordinate complexes 4, 5, and 8 imply that the strong σ-donor, weak π-acceptor CN- ligands play a key role in creating/stabilizing five-coordinate iron(II) [(CN)2(CO)Fe(S,S-C-R)]- complexes with a vacant coordination site trans to the CO ligand.
AB - The dicyanodicarbonyliron(II) thiolate complexes trans, cis-[(CN)2(CO)2Fe(S,S-C-R)]- (R = OEt (2), N(Et)2 (3)) were prepared by the reaction of [Na][S-C(S)-R] and [Fe(CN)2(CO)3(Br)]- (1). Complex 1 was obtained from oxidative addition of cyanogen bromide to [Fe(CN)(CO)4]-. In a similar fashion, reaction of complex 1 with [Na][S,O-C5H4N], and [Na][S,N-C5H4] produced the six-coordinate trans,cis-[(CN)2-(CO)2Fe (S,O-C5H4N)]- (6) and trans,cis-[(CN)2 (CO)2Fe(S,N-C5H4)]- (7) individually. Photolysis of tetrahydrofuran (THF) solution of complexes 2, 3, and 7 under CO led to formation of the coordinatively unsaturated iron(II) dicyanocarbonyl thiolate compounds [(CN)2(CO)Fe(S,S-C-R)]- (R = OEt (4), N(Et)2 (5)) and [(CN)2(CO)Fe(S,N-C5H4)]- (8), respectively. The IR νCN stretching frequencies and patterns of complexes 4, 5, and 8 have unambiguously identified two CN- ligands occupying cis positions. In addition, density functional theory calculations suggest that the architecture of five-coordinate complexes 4, 5, and 8 with a vacant site trans to the CO ligand and two CN- ligands occupying cis positions serves as a conformational preference. Complexes 2, 3, and 7 were reobtained when the THF solution of complexes 4, 5, and 8 were exposed to CO atmosphere at 25 °C individually. Obviously, CO ligand can be reversibly bound to the FeII site in these model compounds. Isotopic shift experiments demonstrated the lability of carbonyl ligands of complexes 2, 3, 4, 5, 7, and 8. Complexes [(CN)2(CO)Fe(S,S-C-R)]- and NiA/NiC states [NiFe] hydrogenases from D. gigas exhibit a similar one-band pattern in the νCO region and two-band pattern in the νCN region individually, but in different positions, which may be accounted for by the distinct electronic effects betwen [S,S-C-R]- and cysteine ligands. Also, the facile formations of five-coordinate complexes 4, 5, and 8 imply that the strong σ-donor, weak π-acceptor CN- ligands play a key role in creating/stabilizing five-coordinate iron(II) [(CN)2(CO)Fe(S,S-C-R)]- complexes with a vacant coordination site trans to the CO ligand.
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U2 - 10.1021/ja011504f
DO - 10.1021/ja011504f
M3 - Article
C2 - 11853444
AN - SCOPUS:0037181028
VL - 124
SP - 1680
EP - 1688
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 8
ER -