Formation of Thioarsenide from the Reductive Coupling of Dithionite and Arsenite under Hydrothermal Conditions. Synthesis of (Ph4P)[Fe2(AsS)(CO)6]

The iron carbonyl cluster compound (Ph#)[Fe2(AsS)(C0)6] (1) containing the thioarsenate ligand Ass3has been hydrothemally synthesized at 130 "C from a mixture of Fe3(C0)12, NaAsO2, NazS204, and P W B r in the 1:3:6:3 molar ratio. This air-stable, orange yellow compound crystallizes in the triclinic space group P-1 (No. 2) with a = 11.409(2) A, b = 12.273(3) A, c = 12.277(3) A, a = 108.17(2)", p = 102.05(2)", y = 106.60(2)", V = 1479(1) A3, and Z = 2. The [Fe2(AsS)(CO)6]anion in 1 is isostructural and isoelectronic to Fez(S2)(C0)6.