Reactions of thioarsines with metal carbonyls: synthesis and structural characterisation of [Fe-2(CO)(6)(mu-AsMe2)(mu-SPh)], [Fe2Cp2(CO)(2)(mu-AsPh2)(mu-SPh)], [Mn-2(CO)(8)(mu-AsPh2)(mu-SPh)] and [Co-3(mu(3)-S)(mu-AsPh2)(CO)(6)AsPh3]

The thioarsine, AsMe2(SPh), reacts thermally with [Fe(CO)(5)] to give the n ew bimetallic butterfly complex, [Fe-2(CO)(6)(mu-AsMe2)(mu-SPh)] (1). Simil arly, thermolysis of the thioarsine AsPh2(SPh) with [Fe2Cp2(CO)(4)] and [Mn -2(CO)(10)] affords, respectively [Fe2Cp2(Co)(2)(mu-AsPh2)(mu-SPh)] (2) and [Mn-2(CO)(8)(mu-AsPh2)(mu-SPh)] (3). At room temperature, AsPh2(SPh) react s rapidly with [Co-2(CO)(8)] to yield the trimetallic product, [Co-3(mu(3)- S)(mu-AsPh2)(CO)(6)AsPh3] (4). The crystal structures of these four product s have been determined by X-ray crystallography. Arsenic-sulfur bond cleava ge is a feature of all these reactions; concomitant arsenic-carbon bond for mation is observed in the production of complex 4. (C) 1999 Elsevier Scienc e S.A. All rights reserved.