Synthesis and reactivity of binuclear copper(I) complexes of 2-(diphenylphosphino)-6-(pyrazol-1-yl)pyridine (L1).: Crystal structures of [Cu2(μ-L1)2(MeCN)2][ClO4]2, [Cu2(μ-L1)2(μ-η1-CCPh)][ClO4]•CHCl3•H2O and [Cu2(μ-L1)2(μ-Cl)][ClO4]•H2O

Reaction of 2-(diphenylphosphino)-6-(pyrazol-1-yl)pyridine (L-1) with 1 equivalent of [Cu(MeCN)(4)][ClO4] resulted in the formation of [Cu-2(mu-L-1)(2)(MeCN)(2)][ClO4](2) 1. Complex 1 reacted with Li(C=CPh) to give [Cu-2(mu-L-1)(2)-(mu(1)-C=-CPh)][ClO4] 2, which underwent an alkynyl ligand-transfer reaction with [Pd(PBu"(3))(2)Cl-2] to give [Cu-2(mu-L-1)(2)(mu-Cl)][ClO4] 3 and [Pd(PBu"(3))(2)(C=Ph)Cl]. Reaction of 1 with dimethyl acetylenedicarboxylate yielded [Cu-2(Cu-2(mu-L-1)(2)(mu-MeO2CC=CCO2Me)][ClO4](2) 4, the alkynyl ligand of which can easily be displaced by bis(diphenylphosphino)methane (dppm) to give [Cu-2(mu-L-1)(2)(mu-dppm)][rClO(4)](2) 5. The crystal structures of 1, 2 . CHCl3 . H2O and 3 . H2O have been determined.