Synthesis, Crystal Stuctures, and Properties of Two 1D Cadmium(II) Coordination Polymers Based on Ferrocenylcarboxylate

Abstract

Self-assemblies of the flexible ferrocenyl block 2-chloro-4-ferrocenylbenzoate with Cd²⁺ cations in the presence of N-containing auxiliary ligand result in two coordination complexes, namely, &{[Cd(η² -OOCClH₃C₆Fc)₂(Mbbz)(CH₃OH)] · (H₂O)0.5}_n (I) and [Cd(η² -OOCClH₃C₆Fc)₂(Bbbm)]_n (II) {Fc = (η⁵- C₅H₄)Fe(η⁵-C₅H₄), Mbbz = 1,1'-methyl benzimidazole, Bbbm = 1,4-bis(benzimidazol-1-ylmethyl)-benzene}. Their structure has been determined by single-crystal X-ray diffraction analyses (CIF files nos. 1529095 (I), 1529096 (II)) and further characterized by elemental analyses, IR spectra, and thermogravimetric analyses. Crystallographic characterization shows that both I and II are 1D chain structures. Notably, various C–H···π interactions and C–H···Cl interactions are discovered in I and II, and they have significant contributions to self-assembly, which extend 1D complex to infinite 3D supramolecular networks. Moreover, the electrochemical studies of I and II in DMF solution display irreversible redox waves and indicate that the half-wave potentials of the ferrocenyl moieties in I and II are shifted to positive potential compared with that of free 2-chloro-4-ferrocenylbenzoate.