One-dimensional Cu(I) and Ag(I) ladder-like coordination polymers supported by 2-ethyl-1-(pyridin-3-ylmethyl)-1H-benzimidazole.

The title complexes, poly[[bis[μ2-2-ethyl-1-(pyridin-3-ylmethyl)-1H-benzimidazole-κ(2)N(1):N(3)]copper(I)] tetrafluoroborate acetonitrile monosolvate], {[Cu(C15H15N3)2]BF4·CH3CN}n, (I), and poly[[bis[μ2-2-ethyl-1-(pyridin-3-ylmethyl)-1H-benzimidazole-κ(2)N(1):N(3)]silver(I)] perchlorate methanol monosolvate], {[Ag(C15H15N3)2]ClO4·CH3OH}n, (II), are isostructural and exhibit one-dimensional ladder-like structures in which each asymmetric unit contains one metal ion (Cu(+) or Ag(+)), two 2-ethyl-1-(pyridin-3-ylmethyl)-1H-benzimidazole (bep) ligands, one counter-anion (tetrafluoroborate or perchlorate) and one interstitial molecule (acetonitrile or methanol). Each metal ion exhibits a distorted tetrahedral coordination geometry consisting of two pyridyl and two benzimidazole N atoms from four distinct ligands. Two metal ions are linked by two bep ligands to form a centrosymmetric 18-membered M2(bep)2 metallacycle, while adjacent M2(bep)2 metallacycles are further interlinked by another two bep ligands resulting in a ladder-like array. In the extended structure, four adjacent ladder-like arrays are connected together through C-H···F, O-H···O and C-H···O hydrogen bonds between bep ligands, solvent molecules and counter-anions into a three-dimensional supramolecular structure.