Syntheses and structures of Cd(II) and Co(II) compounds of 4-[(3-pyridyl)methylamino]benzoate anion

Abstract

Three coordination polymers containing Cd(II) and Co(II), connected via 4-[(3-pyridyl)methylamino]benzoate (L⁻), have been synthesized in hydrothermal conditions. In [Cd(L)Cl] _n (1), adjacent Cd(II) cations are linked by carboxylates to give a dinuclear cluster. Pairs of L⁻ bridge the dinuclear cluster to form double helical chains, and these chains are further linked by Cl⁻ to produce a 4-connected net with (4² · 6³ · 8) topology. [CdL₂] _n (2) contains 1-D ladder-like chains. The packing structure displays a 3-D supramolecular structure, with π ··· π interactions stabilizing the framework. [CoL₂] _n (3) has a 2-D extended supramolecular structure via π ··· π interactions of 1-D coordination polymers of 3. The crystal structures of 1–3 have been determined by single-crystal X-ray diffraction. Luminescent properties for 1 and 2 are discussed.

Keywords:

• Cadmium
• Cobalt
• Coordination polymers
• Topology

Acknowledgments

We thank the Program for Changjiang Scholars and Innovative Research Teams in Chinese University, the Fundamental Research Funds for the Central Universities, the Specialized Research Fund for the Doctoral Program of Higher Education, China Postdoctoral Science Foundation (20080431050 and 200801352), the Postdoctoral Foundation of Northeast Normal University (NENU), the Training Fund of NENU's Scientific Innovation Project, and the Analysis and Testing Foundation of NENU for support.