Tetrathiafulvalene-functionalized phosphine as a coordinating ligand. X-Ray structures of (PPh2)4TTF and [(AuCl)4{(PPh2)4TTF}]

Abstract

The phosphine (PPh₂)₄TTF (P4) (1) reacts with the gold(I) complexes [AuX(tht)] (X = Cl, C₆F₅; tht = tetrahydrothiophene) or [Au(Mes)(AsPh₃)] (Mes = 2,4,6-Me₃C₆H₂) to give tetranuclear derivatives [(AuX)₄P4] (X = Cl, 2; C₆F₅, 3; Mes, 4). The analogous reaction starting with [Au(Trip)(AsPh₃)] (Trip = 2,4,6-Prⁱ₃C₆H₂) provides the dinuclear derivative [(AuTrip)₂P4] (5). When the phosphine P4 reacts with [Cu(MeCN)₄]PF₆, AgCF₃SO₃ or [Au(tht)₂]CF₃SO₃ in a 2∶1 molar ratio, complexes [M(P4)₂]A (A = PF₆, M = Cu, 6; A = CF₃SO₃, M = Ag, 7, Au, 8) are obtained, or {[M₂P4](CF₃SO₃)₂}_n (M = Ag, 9; Au, 10) when 1∶1 molar ratios are used instead. Visible-ultraviolet and electrochemical studies of the new complexes are reported. Two, reversible one-electron oxidations to the mono- and di-cation occur in complexes 2–10 at more positive potentials than the two reversible oxidations exhibited by the free P4 (1) ligand. The structures of 1 and 2 have been confirmed by X-ray analysis.