Two different 2,2′-bipyridine cadmium(II) perchlorate complexes, [Cd(2,2′-bipy)₂(H₂O)(ClO₄)]ClO₄ and [Cd(2,2′-bipy)₃](ClO₄)₂·0.5 2,2′-bipy, syntheses, characterization, thermal and structural studies

Abstract

Reactions of 2,2′-bipyridine (2,2′-bipy) with cadmium perchlorate in a ratio of M : L 1 : 2 and 1 : 3 give complexes with stoichiometry [Cd(2,2′-bipy)₂(H₂O)(ClO₄)]ClO₄ (1) and [Cd(2,2′-bipy)₃](ClO₄)₂ · 0.5 2,2′-bipy (2), respectively. The new complexes were characterized by elemental analyses and IR-, ¹H-, ¹³C-NMR spectroscopy. The crystal structures of the [Cd(2,2′-bipy)₂(H₂O)(ClO₄)]ClO₄ (1) and [Cd(2,2′-bipy)₃](ClO₄)₂ · 0.5 2,2′-bipy (2) were determined by X-ray crystallography and the their thermal behavior studied by TG and DTA. Complexes 1 and 2 are built up of monomeric [Cd(2,2′-bipy)₂(H₂O)(ClO₄)]ClO₄ and [Cd(2,2′-bipy)₃](ClO₄)₂ · 0.5 2,2′-bipy with Cd²⁺ coordination, CdN₄O_waterO_perchlorate and CdN₆, respectively. There are classical O–H ··· O_perchlorate hydrogen bonds in complex 1 and non-classical C–H ··· O_perchlorate approaches in complex 2. The monomeric units of 1 and 2 grow into dimeric and one-dimensional units by packing via hydrogen bonding.

Keywords:

• Cd(II)
• 2,2′-Bipyridine
• Crystal structure
• Thermal behavior

Acknowledgements

Support of this investigation by Tarbiat Modarres University is gratefully acknowledged.