Dithiophosphinate complexes of the actinides. Part 1. Preparation and characterisation of complexes of thorium(IV) and the crystal structures of [Th(S2PR2)4], R = Me or C6H11

Abstract

Reaction of dithiophosphinate salts with hydrated ThCl₄ in the ratio 4 : 1 in ethanolic solution yields the complexes [Th(S₂PR₂)₄] where R = Me, Et, Prⁱ, Ph, C₆H₁₁, OEt, or Oprⁱ, The air-stable complexes have been characterised by their elemental analysis, i.r., and n.m.r. spectra, and the crystal structures have been determined for R = Me and C₆H₁₁. Crystals of [Th(S₂PMe₂)₄] are tetragonal, space group P4₂2₁2, with a= 10.521(1) and c= 11.936(1)Å(R= 0.030). Crystals of [Th{S₂P(C₆H₁₁)₂}₄] are monoclinic, space group C2/c, with a= 42.521(5), b= 11.754(2), c= 23.945(2)Å, and β= 100.285(8)°(R= 0.048). The thorium atoms are surrounded by eight sulphur atoms (av. Th–S = 2.910 Å) in a dodecahedral arrangement (the methyl compound having crystallographic 222 symmetry). In both cases the M(L–L)₄mmmm isomer is formed.