New metal diselenolene complexes with the formula [M(Se2C2(CF3)2)2]z (M = Pt, z = 0, -1, -2; M = Au, z = -1) have been prepared by the reaction of bis(trifluoromethyl)diselenete, (CF3)2C2Se2, with (Ph3P)2PtCl2 and (Ph3P)AuCl, respectively; the previously known Ni and Cu analogues have been similarly obtained. Comparison of electrochemical data for these complexes with those of the corresponding metal bis(dithiolene) complexes indicates that substitution of selenium for sulfur does not dramatically alter the electronic structure. Analysis of ESR spectra of the paramagnetic [M(Se2C2(CF3)2)2]- (M = Ni, Pt) anions indicates that the majority (ca. 70%) of the unpaired spin is located on the four selenium atoms. The neutral complex [Pt-(Se2C2(CF3)2)2] exhibits an unusual associational equilibrium in solution that has been studied by UV-vis and 19F NMR spectroscopy. The X-ray crystal structure of [(C6H5)4P] [Pt(Se2C2(CF3)2)2] also is reported; the coordination geometry of Pt is nominally square planar, with interatomic distances reflecting substantial multiple-bond character in the Pt-Se bonds. Crystal data: monoclinic, space group P21/c, with a = 18.015 (3) Å, b = 14.280 (4) Å, c = 14.627 (4) Å, β = 112.30 (2)°, V = 3481.4 (9) Å 3, and Z = 4.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry