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A novel binuclear copper complex incorporating a nalidixic acid derivative displaying a one‐dimensional coordination polymeric structure
Author(s) -
Bergamini F. R. G.,
Ribeiro M. A.,
Miranda P. C. M. L.,
Formiga A. L. B.,
Corbi P. P.
Publication year - 2016
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229616008913
Subject(s) - chemistry , hydrazone , coordination polymer , hydrazide , carbohydrazide , crystal structure , tetrazole , stereochemistry , molecule , coordination complex , ring (chemistry) , antibacterial activity , combinatorial chemistry , medicinal chemistry , crystallography , metal , organic chemistry , biology , bacteria , genetics
The identification of the antibacterial action of nalidixic acid (nx) was central to the development of the quinolone antibacterial compounds. The ability of the nx naphthyridyl ring to interact with and inhibit some proteins has encouraged the investigation of similar structures in the search for more active compounds with less adverse effects. The possibility of structural modification by attachment of other biologically active moieties to the naphthyridyl ring of nx allowed the development of new active antimicrobial molecules. Hydrazone derivatives of nx can be synthesized easily based on the condensation of the hydrazide derivative of nx with the desired aldehyde or ketone. Only a few complexes with nx hydrazone derivatives have been described but for none were the crystal structures elucidated. The synthesis of a new one‐dimensional Cu II coordination polymer, namely catena ‐poly[[copper(II)‐di‐μ‐chlorido‐copper(II)‐{μ‐1‐ethyl‐ N ′‐[(1 H ‐imidazol‐4‐yl)methylidene]‐7‐methyl‐4‐oxo‐1,4‐dihydro‐1,8‐naphthyridine‐3‐carbohydrazidato}‐[dimethanolcopper(II)]‐{μ‐1‐ethyl‐ N ′‐[(1 H ‐imidazol‐3‐yl)methylidene]‐7‐methyl‐4‐oxo‐1,4‐dihydro‐1,8‐naphthyridine‐3‐carbohydrazidato}] dichloride methanol tetrasolvate], {[Cu 3 (C 16 H 15 N 6 O 2 ) 2 Cl 2 (CH 3 OH) 2 ]Cl 2 ·4CH 3 OH} n , with the (1 H ‐imidazol‐4‐yl)methylidene carbohydrazide derivative of nalidixic acid (denoted h4imi), is presented and its structure is compared to the density functional theory (DFT) optimized structure of free h4imi. The title structure presents an octahedral Cu II ion on an inversion centre alternating along a polymer chain with a square‐pyramidal Cu II ion, with the two Cu II centres bridged by two chloride ligands. Hydrogen bonds involving chloride counter‐ions and methanol solvent molecules mediate the three‐dimensional packing of the polymer. Comparison of the geometrical results from the structure analysis with those derived from a DFT study of the free ligand reveal the differences that arise upon coordination.