Syntheses and structural characterization of cadmium complexes constructed from a tetrakis(3-pyridylmethyl) functionalized ligand

Abstract

A functionalized ligand (L = 1,4,8,11-tetrakis(3-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane) was synthesized by the reaction of 1,4,8,11-tetraazacyclotetradecane (cyclam, L¹) with 3-(chloromethyl)pyridine hydrochloride. Hydrothermal reactions between L and two Cd(II) salts (nitrate or chloride) led to the formation of [CdCl₂(µ₄-4(pyridyl)L)] _n (1) and [Cd(µ-ONO₂)₂(µ₄-4(pyridyl)L)] _n (2), which were characterized by elemental analysis and single-crystal X-ray diffraction. In 1, Cd is six-coordinate, with a CdN₄Cl₂ octahedral coordination environment forming two metallamacrocycles with the functionalized cyclam. In the structure of 2, the metal possesses a distorted CdN₄O₂ octahedral coordination geometry, also presenting two metallamacrocycles. In both structures, the ligand does not chelate, but forms extended polymeric structures.

Keywords:

• Cadmium complex
• Functionalization
• Metallamacrocycle
• Hydrothermal method

Acknowledgments

The authors are grateful for the financial support from the Innovation Fund of Fujian Province (grant no. 2003J044) and the Scientific Fund of Guangxi University (grant no. X061144).