Two new Zinc(II) and Cadmium(II) complexes of a semi-rigid bis(2-benzimidazole): Synthesis and characterization

ABSTRACT

Two new complexes Zn(TBimE)Cl₂ 1 and Cd(TBimE)(I)₂ 2 based on a semi-rigid ligand TBimE (TBimE = (E)-1,2-bis(2-benzimidazolyl)ethane) have been synthesized and their structures have been determined by X-ray single crystal diffractometry. X-ray diffraction analyses reveal that the “trans” TBimE is converted into “cis” conformation in the structures of the complexes, so that the TBimE can be used as a bidentate ligand to chelate the Zinc(II) and Cadmium(II) ions. Both 1 and 2 exhibit distorted tetrahedral geometries and the central metal atoms are coordinated by two N atoms from TBimE and two anions. The UV–Vis and emission spectra show that both the absorption and the emission of the complexes are assigned to the intraligand transitions and intraligand fluorescence, respectively.

KEYWORDS:

• Zinc(II) complex
• Cadmium(II) complex
• bis(benzimidazoles)
• crystal structure

Funding

This work was supported by the NSF of Guangxi (2014GXNSFBA118052 and 2016GXNSFAA380266), Guangxi University Research Project (XM20141209173713259), Science and Technology Plan of Qingdao (13-1-4-209-jch), and University and Doctoral Foundation of Guilin Medical University.