title: Synthesis, crystal structures and magnetic properties of mer-cyanideiron(III)-based 1D heterobimetallic cyanide-bridged chiral coordination polymers.
abstract: Two pairs of cyanide-bridged Fe(III)–Mn(III)/Cu(II) chiral enantiomer coordination polymers {[Mn(S,S/R,R-Salcy)(CH3OH)2]{[Mn(S,S/R,R-Salcy)][Fe(bbp)(CN)3]}}2n (1,2) (bbp = bis(2-benzimidazolyl)pyridine dianion) and {[Cu(S,S/R,R-Chxn)2]2[Fe2(tbbp)(CN)6]}n (3,4) (tbbp = tetra(3-benzimidazolyl)-4,4′-bipyridine tetraanion) have been successfully prepared by employing mer-tricyanometallate [PPh4]2[Fe(bbp)(CN)3] or the newly bimetallic mer-cyanideiron(III) precursor K4[Fe2(tbbp)(CN)6] as building blocks and with chiral manganese(III)/copper(II) compounds as assemble segments. The four complexes have been characterized by elemental analysis, IR spectroscopy, circular dichroism (CD) and magnetic circular dichroism (MCD) spectra. Single X-ray diffraction reveals that complexes 1 and 2 possess a single anionic chain structure consisting of the asymmetric chiral {[Mn(S,S/R,R-Salcy)][Fe(bbp)(CN)3]}2(2−) unit with free [Mn(S,S/R,R-Salcy)](+) as balanced cations. The cyanide-bridged Fe(III)–Cu(II) complexes 3 and 4 can be structurally characterized as neutral ladder-like double chains composed of the alternating cyanide-bridged Fe–Cu units. Our investigation of magnetic susceptibilities reveals the antiferromagnetic coupling between the cyanide-bridged Fe(III) and Mn(III)/Cu(II) ions for complexes 1–4. These results have been further confirmed by theoretical simulation through numerical matrix diagonalization techniques using a Fortran program or a uniform chain model, leading to the coupling constants J = −7.36 cm(−1), D = −1.52 cm(−1) (1) and J = −4.35 cm(−1) (3), respectively.
authors: College of Chemical Engineering, Shandong University of Technology, Zibo 255049, China. dpzhang73@126.com.
authors: Daopeng
authors: D
authors: Zhang
authors: Shuping
authors: S
authors: Zhuo
authors: Hongyan
authors: H
authors: Zhang
authors: Ping
authors: P
authors: Wang
authors: Jianzhuang
authors: J
authors: Jiang