Synthesis and reactions of dimethyltin dithiooxalate: a convenient dithiooxalate transfer reagent

摘要

Dimethyltin dithiooxalate has been synthesised by the reaction of dimethyltin dichloride with potassium dithiooxalate. It may be used as a dithiooxalate (dto) transfer reagent, reacting with [PtL_2Cl_2] [L_2 = 1,4-cyclooctadiene or 4,4'-bis(tert-butyl)-2,2'-bipyridine) to eliminate SnMe_2Cl_2 and form the corresponding platinum dithiooxalate compounds [Pt(COD)(dto)] 1 and [Pt(~tBu_2bipy)(dto)] 2. Reaction with the ruthenium compound [Ru(Me_2bipy)(PPh_3)_2Cl_2] 3 (Me_2bipy = 4,4'-dimethyl-2,2'-bipyridine) does not proceed analogously however, eliminating from the ruthenium one chloride and one triphenylphosphine ligand, and thus producing not SnMe_2Cl_2 but "[SnMe_2Cl]~+". This moiety becomes chelated within the dithiooxalate to produce the new 'Couccouvanis' type compound [cis-Ru(Me_2bipy)(PPh_3)Cl(mu-dto)(SnMe_2Cl)] 4. Reation of 4 with DMSO causes the elimination of SnMe_2Cl_2 by abstracting the tin centre and the second chloride ligand, producing cis-[Ru(Me_2bipy)(PPh_3)(DMSO)(dto)] 5. Upon treating 3 with [p-N ident to NC_6H_4F][BF_4] the oxidation product [Ru(Me_2bipy)(PPh_3)_2Cl_2][BF_4] 6 is formed. 6 reacts with SnMe_2(dto) to produce a bimetallic complex, [Ru(Me_2bipy)(PPh_3)_2(mu-dto)(SnMe_2Cl)][BF_4] 7a. The nature of the reduction products of 4 and 7 is explored, and the X-ray crystal structures of 2 and 5 are presented.