Three novel dipicolinate complexes with the pyridine-2,6-dimethanol - A combined structural, spectroscopic, antimicrobial and computational study

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• 作者：?brahim Uç ; ar^a ; ^{iucar@omu.edu.tr} ; Ö ; mer Tamer^a ; Bahtiyar Sar?bo?a^b ; Orhan Bü ; yü ; kgü ; ngö ; r^a
• 关键词：Dipicolinic acid ; X-ray diffraction ; Antimicrobial activity ; Vibrational spectra ; UV&ndash ; Vis ; Quantum chemical calculations
• 刊名：Solid State Sciences
• 出版年：2013
• 出版时间：January, 2013
• 年：2013
• 卷：15
• 期：Complete
• 页码：7-16
• 全文大小：924 K

文摘

Three new dipicolinate complexes, [M(dmp)(dpc)]¡¤H₂O [M?=?Co(II) (1); Zn(II) (2); Ni(II) (3); dmp: pyridine-2,6-dimethanol; dpc: dipicolinate or pyridine-2,6-dicarboxylate], were synthesized and combined with experimental and theoretical study on molecular, vibrational and electronical properties. The central M(II) ion in all complexes is bonded to dpc and dmp ligands through pyridine nitrogen atom together with two oxygen atom, forming the distorted octahedral geometry. The complex molecules, connected via O-H?O hydrogen bonds, form a supramolecular structure. The complexes were also screened for antimicrobial activity against human pathogenic Gram-positive, Gram-negative bacteria and fungi. Among the tested microorganisms, Streptococcus pneumoniae was the most sensitive strain, especially to H₂dpc and its complexes. The EPR spectra of Cu²⁺ doped polycrystalline complexes indicate that the paramagnetic center has a rhombic symmetry. Although the supramolecular interactions have some influences on the molecular geometry in solid state phase, calculated data show that the predicted geometries can reproduce the structural parameters. The electronic station in the frontier orbitals of the dipicolinate complexes calculated from the experimental data is compared to the results of time-depended DFT calculations with the polarizable continuum model and UV-Vis spectrum of the complexes has been discussed on this basis. Calculated vibrational frequencies using the DFT and HF method are consistent with the experimental IR data.