Crystal structures of bis-(N-methyl-N-phenyldithiocarbamato)-nickel-(II) and -copper(II)

Abstract

The crystal and molecular structures of the title compounds have been determined by single-crystal X-ray diffraction methods, using conventional Patterson and Fourier heavy-atom methods, followed by block-diagonal least-squares refinement to R 0·116 (Ni) and 0·125 (Cu) for 1106 and 1202 visually estimated independent observed reflections. The compounds are isomorphous and isostructural with monoclinic unit cells, space group P2₁/a, containing two discrete molecules; [Ni(CS₂·NMePh)₂]: a= 19·30 ± 0·02, b= 6·592 ± 0·003, c= 7·658 ± 0·003 Å, β= 107·8 ± 0·1°; [Cu(CS₂·NMePh)₂]: a= 19·40 ± 0·02, b= 6·612 ± 0·003, c= 7·701 ± 0·003 Å, β= 107·5 ± 0·1°.

The heavy atom in each structure occupies the special position (0,0,0), (½, ½,0) with symmetry and is necessarily planar co-ordinated by four neighbouring sulphur atoms at approximately equal distances: Ni–S 2·208(3) and 2·198(3)Å, S(1)–Ni–S(2) 79·2(1)°; Cu–S 2·329(3) and 2·274(3)Å, S(1)–Cu–S(2), 77·7(1)°. The remainder of the S₂CNC₂ ligand fragment is planar and conjugated, with normal geometry. There is evidence for hydrogensulphur intermolecular interactions. The plane of the phenyl ring lies at 82° to that of the conjugated ligand fragment in both cases, apparently as a result of steric interaction with the methyl group, and as a consequence of this both compounds are monomeric although it is usual for bis-(NN-dialkyldithiocarbamato)copper(II) derivatives to be dimeric in the solid state.