Sulphur-ligand–metal complexes. Part 7. The interaction of some diphosphine dichalcogenides and tetra-alkylthiuram disulphides with halogens and some first-row transition-metal salts

Abstract

Iodine interacts with R₂P(X)·[CH₂]_n·(X)PR₂[R = Ph, X = S, n= 1 (L′); R = Ph, X = S, n= 2 (L²); or R = Me, X = S, n= O (L⁴)] to give charge-transfer adducts of the type L·2l₂ or L·l₂, whereas corresponding reactions with R₂N·CS·S₂·CS·NR₂[R = Me (L⁵) or Et (L⁶)] give products of the type L′·l₆ in which L′ is oxidised probablyto give a dication with the cyclised structure [graphic omitted]²⁺(A)(L⁸, R = Et; L⁹, R = Me) with two [l₃]^– as counter ions. The interactions of L′ with FeCl₃, CO[BF₄]₂· 6H₂O and CoCl₂·6H₂O (all in excess) in diethyl ether or acetone–chloroform also give products containing the species (A) in the following complexes; [L⁹][FeCl₄]₂, [L⁸][FeCl₄]₂, [L⁹][BF₄]₂ and [L⁹][CoCl₄] as well as dithiocarbamato-complexes. Dimethylcarbamoyi dimethylthio-carbamoyl disulphide and bis(diethyldithiocarbamylthio)methane with FeCl₃ are each thought to produce cyclised dications similar to (A). With the appropriate copper(II) salts (in excess) and L′ in acetone, the copper(III) derivatives [CuCl₂(S₂CNR₂)] and [Cu(S₂CNR₂)₂][BF₄](R = Me or Et) have been isolated. In the first two cases when the solvent is changed to chloroform–ethanol the copper(II) derivatives [CuCl(S₂CNR₂)] are found. With Ni[BF₄]₂·6H₂O and NiCl₂·6H₂O in excess and acetone as solvent, L′ gives [Ni(S₂CNMe₂)₃]X (X = BF₄^– or Cl^–), the oxidation state of nickel probably being IV, while excess of Fe[ClO₄]₂·6H₂O gives the known iron(IV) derivative [Fe(S₂CNMe₂)₃][ClO₄].