Structural variety of benzimidazole coordinated zinc(II) and cadmium(II) complexes with closo-decaborate anion

Abstract

The features zinc(II) and cadmium(II) complexation with benzimidazole derivatives Bz1–CH=N–R1 (L1), Bz1–CH2–NH–R1 (L2) (Bz1 is 1-methylbenzimidazole, R1 is 4–methoxyphenyl), and Bz2–N=CH–R2 (L3; Bz2 is 1-propylbenzimidazole, R2 is phenol) in the presence of closo-decaborate anion has been studied. A number of new mixed ligand complexes with different coordination modes of the cluster anion have been obtained and structurally characterized: {Cd(L1)2[B10H10–κ2B1,B2]}∙2CH3CN and {Cd(L2)2[B10H10–κ2B2,B6]} with the [B10H10]2– anion, coordinated by metal atom through the apical (B1B2) or equatorial (B2B6) edge of the boron cage, as well as the first examples of complexes {ZnL2(CH3CN)[B10H10–κ3B1,B2,B3]}, {Zn(Bz2–NH2)2(DMSO)[B10H10–κ3B1,B2,B3]}∙3CH3CN, and {Cd(Bz2–NH2)2(DMF)[B10H10–κ3B1,B2,B3]}∙2CH3CN with facial (B1B2B3) coordination of the closo-decaborate anion. For the first time, theoretical IR spectra have been calculated for cadmium(II) complexes with the coordinated [B10H10]2– anion.