Syntheses, Structures, and Photoluminescent Properties\nof Three Silver(I) Coordination Polymers with\n2-(4-Pyridyl)benzimidazole

Abstract

Three silver(I) coordination polymers, namely, [Ag₂(PyBIm)₂(H₂O)₂]SO₄·H₂O (<b>1</b>), [Ag₃(PyBIm)₃(μ₂-SO₄)(HSO₄)]·3H₂O (<b>2</b>), and [Ag₂(PyBIm)₂(μ₂-SO₄)]·4H₂O (<b>3</b>) [PyBIm = 2-(4-pyridyl)benzimidazole] have been\nsynthesized by hydrothermal methods. The Ag(I) atoms in <b>1</b>−<b>3 </b>are all three coordinated, bridged by PyBIm ligands\nvia N_Py and N_BIm donor atoms into a one-dimensional “zigzag” chain based on the [Ag₂(PyBIm)₂]²⁺ unit. The sulfate\ngroups are not coordinated in<b> 1</b>, while they act as bridging ligands in <b>2</b> and <b>3</b>; with the help of μ₂-SO₄, such “zigzag”\nchains are linked into a belt with a ternary-chain structural motif in <b>2</b>; however, in <b>3</b>, a two-dimensional network\nis observed. All the complexes display room-temperature photoluminescence in the visible region, which may be\nassigned to metal-to-ligand charge transfer.