BONDING ABILITY OF 1,1'-BIS(DIPHENYLTHIOPHOSPHORYL)FERROCENE (DPTPF) AND ITS SELENIUM ANALOG TOWARDS COPPER(I) - CRYSTAL-STRUCTURE OF [CU(DPTPF)]BF4

The phosphine chalcogenides Fe[eta-C5H4P(E)Ph(2)](2) (L) [E = nothing (dppf), S (dptpf) or Se (dpspf)] reacted readily with [Cu(MeCN)(4)]X ( X = BF4, PF6 or ClO4) in CH2Cl2 to give quantitatively the monomeric t wo-co ordinated complexes [CuL]BF4 (E = S 1 or Se 2) or polynuclear th ree-co-ordinated derivatives analysing as [CuL(1.5)]X (E = S 3 or Se 4 ), depending on the ligand to copper molar ratio. The complexes have b een characterized by multinuclear NMR spectroscopy. Complexes 3 and 4 reversibly dissociate in solution, as was evident from the concentrati on- and temperature-dependent NMR spectra. The low-temperature H-1, P- 31-{H-1} and F-19 NMR spectra are interpreted in terms of a tetranucle ar structure in which each copper atom is trigonally bonded by bridgin g L ligands and one anion molecule is trapped inside the tetrahedral C u-4(I) cage. Single-crystal X-ray structure determinations were perfor med for the two diphosphine chalcogenides and complex 1. The structure of 1 shows a slightly distorted linear two-co-ordination geometry aro und the copper atom with an S(1)-Cu-S(2) angle of 171.5(2)degrees. The Cu-S bond distances [2.144(5) and 2.140(5) Angstrom] and the Cu-S-P a ngles [100.8(2) and 105.5(2)] point towards a substantially sp(3) hybr idization of the sulfur atoms. In the ferrocene moiety the cyclopentad ienyl rings are virtually parallel (dihedral angle between the two pla nes 6.5 degrees) and staggered by 16.1 degrees.