Two- and three-dimensional silver acetylide frameworks with high-nuclearity silver cluster building blocks assembled using a bifunctional (4-ethynylphenyl)diphenyl phosphine ligand

Abstract

A bifunctional ligand precursor (4-ethynylphenyl)diphenyl phosphine was synthesized and used for constructing silver acetylide frameworks. Its reaction with Ag(I) in the presence of triethylamine afforded silver acetylide [AgL]n, in which L=Ph2P-C6H4-4-CC− could act as a bifunctional ligand bearing both phenylethynide and phosphine binding sites for Ag(I). Reactions of [AgL]n and AgCF3CO2 under different conditions gave four silver acetylides. They are [Ag18L8(CF3COO)6(HCO3)4(DMF)4]n (1, DMF=dimethylformamide), [Ag20L8(CF3COO)12(DMF)6]n (2), [Ag17L6(CF3COO)9(HCO3)2]n (3), and [Ag17L6(CF3COO)9.58(HCO3)1.42]n (4). Crystallographic studies revealed that complex 1 crystallized in the triclinic space group P1¯ with a=14.1252(9)Å, b=18.6012(12)Å, c=25.2137(17)Å, α=108.340(2)°, β=95.386(2)°, γ=95.535(2)°, V=6204.6(7)Å3, and Z=1. Complex 2 crystallized in the monoclinic space group C2/c with a=48.046(4)Å, b=14.1860(10)Å, c=34.943(2)Å, β=98.315(3)°, V=23,566(3)Å3, and Z=4. Complex 3 crystallized in the triclinic space group P1¯ with a=15.5690(7)Å, b=16.7707(8)Å, c=34.0810(16)Å, α=93.4040(10)°, β=100.3690(10)°, γ=94.8250(10)°, V=8697.1(7)Å3, and Z=2. Complex 4 crystallized in the triclinic space group P1¯ with a=15.5396(6)Å, b=16.7595(7)Å, c=34.0225(15)Å, α=93.8140(10)°, β=100.1000(10)°, γ=94.9770(10)°, V=8660.2(6)Å3, and Z=2. The presence of Ag(I)–ethynide, Ag(I)–P and Ag(I)–Ag(I) bonding interactions makes all four silver acetylides to have two- and three-dimensional framework structures with unusual high-nuclearity silver cluster building blocks.