|Budget Amount *help
¥5,100,000 (Direct Cost : ¥5,100,000)
Fiscal Year 1991 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1990 : ¥4,300,000 (Direct Cost : ¥4,300,000)
Mixed-metal cluster compounds have been studies extensively. Above all, mucti interest has been focused on(incomplete)cubane-type clusters. We have reported the reaction of the incomplete cubane-type aqua ion [Mo_3S_4(H_2O)_9]^<4+> with metals(Fe, Co, Ni, Cu, Sn, and lig)or metal ion(Sn^<2+>) to give mixed metal cubane-type aqua cluster ions with Mo_3MS_4 cores. Three kinds of cubanetype mixed metal cores have been reported so far : single, double, and sandwich.
The following are main results obtained.
1. A new type of replacement reactions has been found.
Mo_3MS_4^<4+> (ap) + Cu_<2+> -> Mo_3CuS_4^<4+> (aq) + M^<2+> (M = Fe, Ni)
2. Molecular orbital calculations have been done on incomplete cubane-type sulfide- or oxo-bridged molybdenum cluster compounds [Mo_3S_4(H_2O)_9]^<4+> and [Mo_3O_4(H_2O)_9]^<4+> using DV-Xalpha method, where Slater transition method was applied to get better results.
3. Facile synthetic methods for [Mo_3S_4(H_2O)_9]^<4+> and [W_3S_4(H_2O)_9]^<4+> have been developed using (NH_4)_2MoS_4 and (NH_4)_2WS_4, respectively.
4. Mixed metal clusters[(H_2O)_9Mo_3S_4SbS_4Mo_3(H_2O)_9]^<8+>, [Mo_3InS_4(pts)_2-(H_2O)_<10>]^<3+>, and [Mo_2WNiS_4(H_2O)_<10>]^<4+> have been newly synthesized and the structures determined by X-ray crystallography. Electrochemical analyses of these compounds have also been done.