Iron-sulfur clusters with SiMe2-bridged cyclopentadienyl ligands: [Me2Si(eta(5)-C5H4)(2)](2)Fe5S12, [Me2Si(eta(5)-C5H4)(2)](2)Fe4S6, and [Me2Si(eta(5)-C5H4)(2)](2)Fe4S6(CO) Version 4.0

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Iron-sulfur clusters with SiMe2-bridged cyclopentadienyl ligands: [Me2Si(eta(5)-C5H4)(2)](2)Fe5S12, [Me2Si(eta(5)-C5H4)(2)](2)Fe4S6, and [Me2Si(eta(5)-C5H4)(2)](2)Fe4S6(CO)
vandenBerg W, Boot L, Joosen H, vanderLinden JGM, Bosman WP, Smits JMM, deGelder R, Beurskens PT, Heck J, Gal AW
INORGANIC CHEMISTRY 36: (9) 1821-1828 APR 23 1997

Document type: Article

Language: English

Cited References: 63

Times Cited: 3

Abstract:
The synthesis and characterization of iron-sulfur clusters stabilized by dimethylsilyl-bridged cyclopentadienyl groups are reported. The thermal reaction of Me2Si(eta(5)-C5H4)(2)Fe-2(CO)(4) (1) with S-8 yields the tetranuclear cubane-type cluster compound [Me2Si(eta(5)-C5H4)(2)](2)Fe4S6 (4) and the pentanuclear cluster compound [Me2Si(eta(5)-C5H4)(2)](2)-Fe5S12 (3) in high yields. The photochemical reaction of 1 with S-8 yields the tetranuclear cluster compound [Me2Si(eta(5)-C5H4)(2)](2)Fe4S6(CO) (5), which contains one residual terminal carbonyl. The crystal structures of 3 and 4 have been determined. Crystal data: 3 . CH2Cl2, monoclinic, C2/c, a = 23.480(13) Angstrom, b = 11.192 (4) Angstrom, c = 17.84(3) Angstrom, beta = 118.58(9)degrees, V = 4118(7) Angstrom(3), Z = 4, R = 0.078; 4, triclinic, <P(1)over bar>, a = 8.4787(7) Angstrom, b = 12.9648(9) Angstrom, c = 13.4990(9) Angstrom, alpha = 79.857(8)degrees, beta = 75.293(8)degrees, gamma = 74.041(11)degrees, V = 1370.9(2) Angstrom(3), Z = 2, R = 0.0447. The F5S12 core of 3 has a bowtie Structure in which a central iron atom is octahedrally coordinated by six sulfur atoms from one tetrasulfido and four disulfido groups. The structure of 4 resembles the structure of the known iron-sulfur cluster Cp4Fe4S6. However, 4 shows a markedly enhanced thermal stability compared to Cp4Fe4S6. In their cyclic voltammograms, 4 and 5 exhibit electrochemical behavior typical of cubane-type Cp-iron-sulfur clusters, whereas the cyclic voltammogram of 3 is quite different. The v(CO) mode of 5 has been measured for four different oxidation states of the cluster by means of IR spectroelectrochemical methods. The Mossbauer spectra of 3 and 3(+) are in accordance with their pentanuclear structure.

KeyWords Plus:
METAL-METAL BOND, ANTIFERROMAGNETIC COMPLEXES, MOLECULAR-STRUCTURE, CRYSTAL-STRUCTURE, OXIDATION-STATES, DIMETHYLACETAMIDE, STABILIZATION, COORDINATION, CHEMISTRY, CHROMIUM

Addresses:
CATHOLIC UNIV NIJMEGEN, NIJMEGEN SON RES CTR, DEPT INORGAN CHEM, NL-6525 ED NIJMEGEN, NETHERLANDS.
UNIV HAMBURG, INST ANORGAN & ANGEW CHEM, D-20146 HAMBURG, GERMANY.

Publisher:
AMER CHEMICAL SOC, WASHINGTON

IDS Number:
WW128

ISSN:
0020-1669

Article 23 of 38