Homoleptic Phosphaalkyne Complexes of Silver(I)

By employing silver salts with a weakly coordinating anion Ag[A] ([A]=[FAlOC12F153], [AlOC(CF3)34]), two phosphaalkynes could be coordinated side-on to a bare silver(I) center to form the unprecedented homoleptic complexes [Ag(η2-P≡CtBu)2][FAlOC12F153] (1) and [Ag(η2-P≡CtBu)2][AlOC(CF3)34] (2). DFT calculations show that the perpendicular arrangement in 1 is the minimum energy structure of the coordination of the two phosphaalkynes to a silver atom, whereas for 2 a unique square-planar coordination mode of the phosphaalkynes at Ag+ was found. Reactions with donor molecules yield the trigonally planar coordinated silver salts [((CH3)2CO)Ag(η2-P≡CtBu)2][FAlOC12F153] (3) and [(C7H8)2Ag(η2-P≡CtBu)][FAlOC12F153] (4). All of the compounds were comprehensively characterized in solution and in the solid state.