The complexation of cadmium acetate and propionate by phenanthroline. Structure and properties of [Cd(CH₃COO)₂(C₁₂H₈N₂)(H₂O)] · H₂O and [Cd(CH₃CH₂COO)₂(C₁₂H₈N₂)]₂ · 2CH₃CH₂COOH

Abstract

The coordination compounds [Cd(CH₃COO-κO ¹,O ²)₂(phenanthroline-kN ¹ N ²)(H₂O)] · H₂O (1) and [Cd{μ-(CH₃CH₂COO-κO ¹,O ²)}₂(phenanthroline-κN ¹,N ²)]₂ · 2CH₃CH₂COOH (2) were synthesized and characterized by elemental and thermal analysis and IR spectroscopy. Crystal and molecular structures of both compounds were determined. The complexes are air stable and fairly soluble in water. In both compounds the cadmium is seven-coordinate and contains chelating phenanthroline and two chelating carboxylate groups in the inner coordination sphere. The seventh coordinating oxygen belongs to water in 1 and to bridging carboxylate in 2. All carboxylate groups are bonded unsymmetrically to the central atom. The coordination polyhedra can be described as distorted pentagonal bipyramid (compound 1) and distorted capped tetragonal bipyramid (compound 2). In the structure of 1 intermolecular O(water)–H ··· O (water/carboxylate) hydrogen bonds create a two-dimensional net along the crystallographic a0c plane. Each molecule of 2 is connected to two propionic acid molecules via hydrogen bonds. In both compounds exist π-stacking interactions.

†Deceased.

Keywords:

• Acetate
• Propionate
• Cadmium
• Phenanthroline
• Conductivity
• Crystal and molecular structure
• Hydrogen bonding
• Thermal decomposition

Acknowledgements

This work was financed by funds allocated by the Ministry of Science and Higher Education to the Institute of General and Ecological Chemistry, Technical University of Lodz.

Notes

†Deceased.