STRUCTURAL CHEMISTRY OF MOLYBDENUM IRON SULFUR CLUSTER COMPOUNDS WITH A SINGLE-CUBANE [MOFE3S4]N+ (N = 4-6) CORE AND CRYSTAL-STRUCTURE OF [MOFE3S4(ME2DTC)5].2CH2CL2

[MoFe3S4(Me2dtc)5]-2CH2Cl2(A1·2CH2C1,) crystallizes in the orthorhombic space group Pbcn, with a = 20.335 (13) ⇋, b = 19.978 (2) ⇋ c = 10.357 (3) ⇋, V= 4207.6 ⇋3, dc= 1.835 g/cm3, and Z = 4. The structure was determined from 1525 reflections (F02> 3σ(F02)) and refined by a full-matrix least-squares method to R = 0.074. The complex contains a cubane-like [MoFe3S4]5+core. Each of the four dimethyldithiocarbamate ligands chelates to one of the four metal atoms, and the fifth ligand forms a bridge between Mo and one Fe atoms. A series of single-cubane-like clusters with a core structure of [MFe3S4]n+(M = Mo, W, n = 4–6; M = Fe, n = 3, 4) were prepared by spontaneous self-assembly reactions or by the conversions of compounds with linear frameworks. The structural parameters of the clusters are compared and discussed. The complexes were characterized by Mossbauer effects, cyclic voltammograms, and 1H NMR techniques. Each Fe atom of oxidation state 3+ interacts magnetically with other metal atoms in the [MFe3S4]5+core. The extra electron in the reduced core [MoFe3S4]4+is delocalized among four metal atoms. © 1990, American Chemical Society. All rights reserved.