OXO-BRIDGED AND SULFIDO-BRIDGED SANDWICH CUBANE-TYPE MOLYBDENUM INDIUM MIXED-METAL CLUSTER - SYNTHESIS AND X-RAY STRUCTURE OF [(H2O)9MO3S3OINOS3MO3-(H2O)9](CH3.C6H4.SO3)8.30H2O

The aqua cluster [Mo3(mu3-S)(mu-O)(mu-S)2(H2O)9]4+ (B) reacts with ind ium metal in aqueous solution of Hpts to give a novel sandwich cubane- type molybdenum-indium mixed-metal cluster [(H2O)9Mo3S3OInOS3Mo3(H2O)9 ]8+ (C). The cluster C is oxidized in hydrochloric acid to give the st arting species B, evolution of hydrogen gas being detected. An interme diate is isolated, and is tentatively assigned to Mo3In(mu3-S)(mu-O)(m u-S)25+(aq) (D). The following reaction pathways are proposed: 2B + In --> C; C + H+ --> D + B + 1/2 H-2; D + 2H+ --> B + In3+ + H-2.