Synthesis, Structure, and Properties of Molybdenum and Tungsten Cyano Complexes with Cuboidal M(4)(&mgr;(3)-E)(4) (M = Mo, W; E = S, Se, Te) Cores

V. P. Fedin; I. V. Kalinina; D. G. Samsonenko; Y. V. Mironov; M. N. Sokolov; S. V. Tkachev; A. V. Virovets; N. V. Podberezskaya; M. R. J. Elsegood; W. Clegg; A. G. Sykes

doi:10.1021/ic980956z

Synthesis, Structure, and Properties of Molybdenum and Tungsten Cyano Complexes with Cuboidal M(4)(&mgr;(3)-E)(4) (M = Mo, W; E = S, Se, Te) Cores

Inorg Chem. 1999 May 3;38(9):1956-1965. doi: 10.1021/ic980956z.

Authors

V. P. Fedin¹, I. V. Kalinina, D. G. Samsonenko, Y. V. Mironov, M. N. Sokolov, S. V. Tkachev, A. V. Virovets, N. V. Podberezskaya, M. R. J. Elsegood, W. Clegg, A. G. Sykes

Affiliation

¹ Department of Chemistry, The University of Newcastle, Newcastle upon Tyne, NE1 7RU, U.K.

PMID: 11670972
DOI: 10.1021/ic980956z

Abstract

Four new tungsten and molybdenum cyano complexes of formula KCs(5)[W(4)S(4)(CN)(12)].CH(3)OH.2H(2)O (1), K(6)[W(4)Se(4)(CN)(12)].6H(2)O (2), K(6)[W(4)Te(4)(CN)(12)].5H(2)O (3), and K(7)[Mo(4)Te(4)(CN)(12)].12H(2)O (5) have been prepared by high-temperature 430-450 degrees C reaction of the polymeric chain compounds {W(3)S(7)Br(4)}(x)(), {W(3)Se(7)Br(4)}(x)(), {Mo(3)Te(7)I(4)}(x)() and solid-state WTe(2) with KCN, and crystallization from aqueous solutions. In addition Cs(6)[Mo(4)Te(4)(CN)(12)].2H(2)O (4) has been prepared by oxidation of 5 with bromine water. The molecular structures have been investigated by X-ray crystallography. Mixed-valence (3.5) compounds 1-4 are diamagnetic. Mixed-valence (3.25) compound 5 is paramagnetic (&mgr; = 2.03 &mgr;(B) at 77 K). In addition to the structural data for these complexes IR and UV-vis spectroscopy have been used to characterize the complexes. Cyclic-voltammetry data have shown that M(4)E(4)(n)()(+) (M = Mo, W; E = S, Se, Te) cubes are capable of existing in three oxidation states ranging from the most oxidized (n = 6; 10 electrons) to the most reduced electron-precise (n = 4; 12 electrons). The (77)Se, (125)Te, and (183)W NMR spectra of the cubes (1-3) demonstrate unambiguously the unaltered environments of the W and E atoms in aqueous solution.