New copper complexes containing phosphaalkene ligands. Molecular structure of [Cu{P(Mes*)C(NMe2)(2)}(2)]BF4 (Mes*=2,4,6-tBu(3)C(6)H(2))

Reaction of equimolar amounts of the inversely polarized phosphaalkene tBuP=C(NMe2)(2) (1a) and copper(I) bromide or copper(I) iodide, respectively, affords complexes [Cu3X3{mu-P(tBu)C(NMe2)(2)}(3)] (2) (X = Br) and (3) (X = 1) as the formal result of the cyclotrimerization of a 1:1-adduct. Treatment or 1a with [Cu(L)Cl] (L = PiPr3; SbiPr(3)) leads to the formation of compounds [CuCl(L){P(tBu)C(NMe2)(2)}] (4a) (L = PiPr(3)) and (4b) (L = SbiPr(3)), respectively Reaction of [(MeCN)(4)Cu]BF4 with two equivalents of PhP=C(NMe2)(2) (1b) yields complex [Cu{P(Ph)C(NMe2)(2)}(2)]BF4 (5b). Similarly, compounds [Cu{P(Aryl)C(NMe2)(2)}(2)]BF4 (5c (Aryl = Mes and 5d (Aryl = Mes*)) are obtained from ArylP=C(NMe2)(2) (1c: Aryl = Mes; Id: Mes*) and [(MeCN)(4)Cu]BF4 in the presence of SbiPr(3). Complexes 2, 3, 4a, 4b, and 5b-5d are characterized by means of elemental analyses and spectroscopy (H-1-, C-13{H-1}-, P-31{H-1}-NMR). The molecular structure of 5d is determined by X-ray diffraction analysis.