Department of Science, Institute of Technology Tallaght, Dublin 24, Ireland.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Dec 15;84(1):275-85. doi: 10.1016/j.saa.2011.09.041. Epub 2011 Sep 22.
Novel Ni(II), Co(II), Zn(II) and Mn(II) complexes of coumarin-3-carboxylic acid (HCCA) were studied at experimental and theoretical levels. The complexes were characterised by elemental analyses, FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectroscopy and by magnetic susceptibility measurements. The binding modes of the ligand and the spin states of the metal complexes were established by means of molecular modelling of the complexes studied and calculation of their IR, NMR and absorption spectra at DFT(TDDFT)/B3LYP level. The experimental and calculated data verified high spin Ni(II), Co(II) and Mn(II) complexes and a bidentate binding through the carboxylic oxygen atoms (CCA2). The model calculations predicted pseudo octahedral trans-[M(CCA2)(2)(H(2)O)(2)] structures for the Zn(II), Ni(II) and Co(II) complexes and a binuclear [Mn(2)(CCA2)(4)(H(2)O)(2)] structure. Experimental and calculated (1)H, (13)C NMR, IR and UV-Vis data were used to distinguish the two possible bidentate binding modes (CCA1 and CCA2) as well as mononuclear and binuclear structures of the metal complexes.
新型 Ni(II)、Co(II)、Zn(II) 和 Mn(II) 香豆素-3-羧酸（HCCA）配合物在实验和理论水平上进行了研究。配合物通过元素分析、FT-IR、（1）H NMR、（13）C NMR 和 UV-Vis 光谱以及磁化率测量进行了表征。通过对所研究配合物的分子建模和在 DFT（TDDFT）/B3LYP 水平下计算其 IR、NMR 和吸收光谱，确定了配体的结合模式和金属配合物的自旋态。实验和计算数据验证了高自旋 Ni(II)、Co(II) 和 Mn(II) 配合物以及通过羧酸氧原子（CCA2）的双齿配位。模型计算预测 Zn(II)、Ni(II) 和 Co(II) 配合物具有伪八面体的反式-[M(CCA2)(2)(H2O)(2)]结构，而 [Mn2(CCA2)(4)(H2O)(2)] 结构为双核。实验和计算的（1）H、（13）C NMR、IR 和 UV-Vis 数据用于区分两种可能的双齿配位模式（CCA1 和 CCA2）以及金属配合物的单核和双核结构。
