A reaction of the dinuclear oxometalate [(Bu4N)-N-n](2)[Mo2O7] and (tacn)Mn
Cl3 (tacn = 1,4,7-triazacyclononane) in water afforded a new cubic type Mn-
Mo mixed metal oxide cluster of [{(tacn)Mn}(2)Mo4O16]. 4H(2)O which has a m
oderate bleaching ability towards pinacyanol chloride dye.