Anion coordination chemistry of benzoates with cationic biguanide-cobalt(iii): from binding studies to biological
Bhupesh Kumar1, Ritu Bala1, Vinit Prakash2
1Department of Chemistry, Guru Nanak Dev University Amritsar-143005 Punjab India rituhatta@yahoo.com.
Abstract:
An anion-templated supramolecular strategy based on anion coordination-driven assemblies (ACDA) has been developed using a biguanide-cobalt(iii) complex as a functional building unit. In this approach, benzoate anions (ABA: p-aminobenzoate, NBA: p-nitrobenzoate, MBA: p-methylbenzoate and MEBA: p-methoxybenzoate) act as directing agents, promoting self-assembly with complex cation [Co(Hbig)3]3+ (Hbig: biguanide) via H-bonding and π-π stacking between adjacent para-substituted benzoates. The SCXRD studies also elucidate that benzoates exhibit varying numbers (up to 7) of H-bonding interactions with the complex cation as well as with lattice water. These interactions collectively facilitate the construction of ACDA and contribute to the overall stability of the supramolecular architecture. These architectures were also characterized by using spectroscopic techniques (UV-visible, FTIR and NMR), DLS and TGA. Anion coordination studies were performed to measure the binding affinities of benzoate anions towards the complex cation, signifying strong and selective anion coordination of NBA. Additionally, the ACDA were evaluated for biological activity (anticancer and antimicrobial), revealing promising potential as compared to their respective standard drugs.
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