Reactions of Triangular Molybdenum and Tungsten Clusters with Tetrabromocatechol

The reaction of cluster complex ( n Bu 4 N) 2 [Mo 3 Se 7 Br 6 ] with tetrabromocatechol (H 2 Tbc) in the presence of Et 3 N and Ph 4 PBr results in the formation of (Ph 4 P) 2 [Mo 3 Se 7 (Tbc) 3 ]∙2MeOH ( Ia ∙2MeOH). Under the same conditions, the tungsten analogue ( n Bu 4 N) 2 [W 3 S 7 Br 6 ] is completely or partly destroyed to give the complex (Ph 4 P)(Et 3 NH)[WO 2 (Tbc) 2 ] ( II ). The structures of Ia ·2MeOH and II were established by X-ray diffraction analysis (CCDC nos. 2213900 and 2213901, respectively). The redox properties of complex Ia and related (Ph 4 P) 2 [Mo 3 S 7 (Tbc) 3 ] ( Ib ) and (Ph 4 P) 2 [Mo 3 S 7 (Tcc) 3 ] ( Ic ) (Tcc is tetrachlorocatecholate) were also studied by cyclic voltammetry.