Synthesis and structural characterization of hybrid Group 12, 14, 15 metals-molybdenum (tungsten) cluster compounds

For the heterometallic cluster compounds containing a core of [M3YS3M')((4 + n)+) (M = Mo, W; Y = O, S; M'= metal atom except Mo, W), a relatively com prehensive understanding has already been made when M'(n +) appears to be a transition metal. When M'(n +) is a main group metal, however, what will b e the situation? This certainly arouses the interest among the chemists. In this present work, the synthesis, new reaction types, crystal structures a nd spectroscopic characterization of a series of 33 hybrid Mo(W)-Group 12, 14, 15 metal clusters are summarized. These crystals can be put into three categories, i.e. the single cubane type which contains a [M3YS3M'] core (M = Mo, W; Y = 0, S; M'= Sn, Pb, Sb, Bi) (SC type), the double cubane cluster s coupled by two bridging oxygen atoms possessing a [Mo3OS3M' (mu -O)](2) c ore (M'= Pb, Bi) (DC type) and the ionic clusters (IO type) which consists of a {Mo-3} cluster cation and a M' complex anion (M' = Cd, Hg). It is show n that the incorporation of the main group metal M' is through M'-S bonding between M' and three (V-S) atoms of the [M3YS3] cluster core, similar to t he case when M' is a transition metal atom. The bonding is however comparat ively looser than in the case of a transition metal. The synthetic reaction s and structural features of these clusters are discussed. Furthermore, inf ormation on the third-order nonlinear optical property observed in some of these compounds is reported. (C) 2001 Elsevier Science Ltd. All rights rese rved.