Journal article
Tetrahedral Complexes Containing the FeIIS4 Core. The Syntheses, Ground-State Electronic Structures, and Crystal and Molecular Structures of the [P(C6H5)4]2Fe(SC6H5)4 and [P(C6H5)4]2Fe(S2C4O2)2 Complexes. An Analogue for the Active Site in Reduced Rubredoxins (Rdred)
Journal of the American Chemical Society, Vol.103(12), pp.3350-3362
01/01/1981
DOI: 10.1021/ja00402a020
Abstract
The synthesis of the [P(C6H5)4]2Fe(SC6H5)4 (I) and [P(C6H5)4]2Fe(S2C4O2)2 (II) complexes is described in detail. I crystallizes in the orthorhombic, polar space group Pbc2h with four molecules in the unit cell. The cell dimensions are a = 13.797 (3) Å, b = 17.542 (4) Å, and c = 24.913 (5) Å. II crystallizes in the monoclinic space group P21/c with four molecules in the unit cell. The cell dimensions are a = 17.402 (7) Å, b = 16.680 (5) Å,c= 18.242 (6) Å, and s = 110.53 (2)°. Intensity data for both I and II were collected with a four-circle computer-controlled diffractometer with use of the 0-20 scan technique. In both structures the carbon atoms in the cations were refined with isotropic temperature factors. In both structures all other nonhydrogen atoms were refined with anisotropic temperature factors. Refinement by full-matrix least squares of 472 parameters on 4929 data for I and 308 parameters on 2801 data for II gave final R values of 0.047 and 0.055 for I and II, respectively. In both structures the hydrogen atoms were included in the structure factor calculation but were not refined. The overall description of the FeS4 central unit in both I and II is that of a distorted tetrahedron formed by four monodentate SC6H5- ligands in I and two bidentate S2C4O2-2. chelates in II. Average values of selected structural parameters and the standard deviations of the mean for the two structures are as follows. For I: Fe-S = 2.353 (9) Å; S-S = 3.837 (18) Å; C-S = 1.767 (19) Å; Fe-S-C = 110.8 (1.9)°; range in Si-Fe-Sj angles = 97.89 (9)-1 19.00 (10)° For II, Fe-S = 2.389 (7) Å; S-S(bite) = 3.922 (14) Å; C-S = 1.688 (9) Å; Fe-S-C = 92.1 (8)°; range in Sii-Fe-Sj angles = 95.57 (11)-124.86 (13)°. The distortions in the FeS4 tetrahedron in II arise from steric constraints from the S2C4O2 ligand. A complete analysis of various structural parameters in a number of [M(SC6H5)4]2. tetrahedra with M = Ni, Co, Zn, Cd, and Fe and for two different types of counterions reveals that the distortions of the MS4 central unit arise from intramolecular, ortho phenyl hydrogen-sulfur and metal interactions. The Mossbauer spectra of I and II have been studied as a function of temperature and an externally applied magnetic field. Values of the fine and hyperfme parameters for I and the magnetic moment (µeff = 5.1 µB) are very similar to those reported for reduced rubredoxin (Rdred). The visible spectra of I also are similar to those obtained for Rdred. On the basis of the available data it is clear that the electronic ground state for I is very similar to the one in Rdred.
Details
- Title: Subtitle
- Tetrahedral Complexes Containing the FeIIS4 Core. The Syntheses, Ground-State Electronic Structures, and Crystal and Molecular Structures of the [P(C6H5)4]2Fe(SC6H5)4 and [P(C6H5)4]2Fe(S2C4O2)2 Complexes. An Analogue for the Active Site in Reduced Rubredoxins (Rdred)
- Creators
- D CoucouvanisD SwensonN C BaenzigerC MurphyD G HolahN SfarnasA SimopoulosA Kostikas
- Resource Type
- Journal article
- Publication Details
- Journal of the American Chemical Society, Vol.103(12), pp.3350-3362
- Publisher
- Amer Chemical Soc
- DOI
- 10.1021/ja00402a020
- ISSN
- 0002-7863
- eISSN
- 1520-5126
- Number of pages
- 13
- Language
- English
- Date published
- 01/01/1981
- Academic Unit
- Chemistry
- Record Identifier
- 9984622750502771
Metrics
1 Record Views