Four novel sulfur-rich complexes: syntheses, crystal structures of three nickel(II) and one cobalt(II) complex with derivatives of Lawesson's Reagent

Bis[O-propan-2-yl (4-eth-oxy-phen-yl)dithio-phospho-nato-κ(2) S,S']nickel(II)

The title compound, [Ni(C₁₁H₁₆O₂PS₂)₂], is a neutral four-coordinate mononuclear complex with a square-planar geometry. The complex lies on an inversion center. The metal atom is surrounded by two chelating isobidentate O-propan-2-yl (4-eth­oxy­phen­yl)dithio­phospho­nate ligands in a trans configuration binding through the S-donor atoms. The Ni—S bond lengths are 2.2328 (5) and 2.2369 (5) Å, an insignificant difference to be considered anisobidentate. The Ni⋯P separation is 2.8224 (5) Å and the S—P bond lengths are 2.0035 (7) and 2.0053 (7) Å. The S—Ni—S (chelating) and S—Ni—S (trans) bond angles are 88.321 (18) and 180°. The Ni—S—P bond angles are 83.26 (2) and 83.33 (2)°, indicating a very minor distortion from ideal square-planar geometry for the Ni atom. The P atom, however, is distorted quite significantly from an ideal tetra­hedral geometry, as reflected by the S—P—S and O—P—C bond angles of 101.93 (3) and 100.70 (7)°, respectively.

Bis[O-propyl (4-eth-oxy-phen-yl)dithio-phospho-nato-κ(2) S,S']nickel(II)

The title compound, [Ni(C₁₁H₁₆O₂PS₂)₂], contains a four-coordinate Ni^II cation with an idealized square-planar geometry. The metal atom is surrounded by two chelating isobidentate dithio­phospho­nate ligands in a trans or anti configuration, binding through the S-donor atoms.

Bis[O-methyl (4-eth-oxy-phen-yl)dithio-phospho-nato-κ(2) S,S']nickel(II)

In the title compound, [Ni(C9H12O2PS2)2], the Ni(II) atom resides on an inversion center and is coordinated by four S atoms [Ni-S = 2.2328 (4) and 2.2455 (3) Å] in a distorted square-planar geometry [S-Ni-S = 88.443 (13) and 91.557 (13)°]. In the crystal, mol-ecules related by translation in [110] are linked into chains via weak C-H⋯O inter-actions. The crystal packing exhibits short inter-molecular S⋯S contacts of 3.3366 (5) Å.

Synthesis and structure of novel [Ph(RO)PSe2]– complexes

Reaction of (PhPSe2)2(Woollins reagent) with NaOR (R = Me, Et, (i)Pr) gives the non-symmetric phosphonodiselenoato anions [Ph(RO)PSe2]- which can be complexed to a range of metals. The nickel complex Ni[Ph(MeO)PSe2]2 adopts a square-planar ML2 structure while the cadmium complex Cd[Ph(MeO)PSe2]2 displays a dimeric M2L4 structure. Two different lead complexes are observed, one consisting of PbL2 units joined by Pb...Se interactions to form distinct dimeric pairs. The other displays a novel dimeric structure built around a central four-membered Pb2Se2 ring. All new compounds have been characterised spectroscopically (31P, 1H, 13C NMR, IR, mass spectroscopy), by elemental analysis and five demonstrative X-ray structures are reported.