Syntheses, Structures, and Photoluminescent Properties of Three Silver(I) Coordination Polymers with 2-(4-Pyridyl)benzimidazole

Abstract

Three silver(I) coordination polymers, namely, [Ag 2 (PyBIm) 2 (H 2 O) 2 ]SO 4 ·H 2 O ( 1 ), [Ag 3 (PyBIm) 3 (μ 2 -SO 4 )(HSO 4 )]·3H 2 O ( 2 ), and [Ag 2 (PyBIm) 2 (μ 2 -SO 4 )]·4H 2 O ( 3 ) [PyBIm = 2-(4-pyridyl)benzimidazole] have been synthesized by hydrothermal methods. The Ag(I) atoms in 1 − 3 are all three coordinated, bridged by PyBIm ligands via N Py and N BIm donor atoms into a one-dimensional “zigzag” chain based on the [Ag 2 (PyBIm) 2 ] 2+ unit. The sulfate groups are not coordinated in 1, while they act as bridging ligands in 2 and 3; with the help of μ 2 -SO 4, such “zigzag” chains are linked into a belt with a ternary-chain structural motif in 2; however, in 3, a two-dimensional network is observed. All the complexes display room-temperature photoluminescence in the visible region, which may be assigned to metal-to-ligand charge transfer.