A serial of cyanide-bridged CrIII/I-CuII complexes from 0D cluster to 2D network: Synthesis, crystal structure and magnetic property

One cyanide-bridged heterometallic achiral complex and two pairs of enantiomers {[Cu(Chxn)2Cr(bpb)(CN)2] ClO4}center dot CH3OH center dot H2O (1), {[Cu(S,S/R,R-Chxn)2Cr(CN)5(NO)]2[Cu(S,S/R,R-Chxn)2(H2O)2]}n center dot 3nH2O (2, 3) {[Cu(S, S/R,R-Chxn)2]3[Cr(CN)5(NO)]2}n center dot 5nH2O (4, 5). (bpb = bis(2-benzimidazolyl)pyridine dianion, Chxn = 1,2-diaminocyclohexane) have been assembled from two cyano containing Cr(I) or Cr(III) building blocks, K[Cr(bpb) (CN)2] and K3[Cr(CN)5(NO)], and racemic or chiral copper(II) compounds under the different reaction condi-tions. The complexes have been characterized by element analysis, IR spectra, the circular dichroism (CD) spectrum, powder and single crystal X-ray diffraction. X-ray structural analyses revealed that the divers structure types of complexes 1-5 ranging from discrete polynuclear entity (1), 1D coordination polymer (CP) anionic chain (2, 3) to neutral 2D CP network (4, 5), indicating clearly the important role of the building block and preparation method on tuning the structure of the target cyanide-bridged complexes. The magnetic properties for the re-ported complexes have been experimentally studied and theoretically simulated, disclosing the ferromagnetic coupling between the Cr(III) ion and Cu(II) ion and the rare antiferromagnetic interaction within Cr(I-Cu(II) unit through the cyanide bridge, respectively. Furthermore, the magnetic coupling nature has been analyzed based-on the magneto-structural correlation.