Structures of Carbonato and Bicarbonato Complexes of Bis(1,10‐phenanthroline)Zinc(II): Experiment and Theory

Abstract

We report experimental and theoretical studies on the structure and properties of carbonato and bicarbonato complexes of bis(1,10‐phenanthroline)zinc(II). The complex [Zn(phen)2O2CO] has been synthesized and DFT calculations have been performed based upon its X‐ray structure. The carbonate ligand coordinates in a bidentate binding mode to the metal centre with Zn−O distances of 2.130 and 2.092 Å in the X‐ray structure and 2.027 Å for both distances in the calculated gas‐phase structure. Because of the fundamental role of (bicarbonato)ZnII complexes, especially in different carbonic anhydrases, the structures and properties of the experimentally unknown bicarbonato complexes of this kind were investigated using DFT with different basis sets up to the Ahlrichs triple zeta basis set with additional polarization functions. The bidentate bicarbonato complex [Zn(phen)2O2C(OH)]+ was found to be about 8.2 kcal·mol−1 (SHAsvp), 6.4 kcal·mol−1 (Ahlrichs triple zeta with polarization functions) and 3.5 kcal·mol−1 (Ahlrichs triple zeta) more stable than the quasi‐monodentate bicarbonato complex [Zn(phen)2O(OH)CO]+. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Exploring the cytotoxic activity of new phenanthroline salicylaldimine Zn(II) complexes

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