Department of Biochemistry and National Magnetic Resonance Facility at Madison (NMRFAM), University of Wisconsin-Madison, Madison, WI 53706, USA.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Jan 3;117:485-92. doi: 10.1016/j.saa.2013.08.044. Epub 2013 Aug 24.
A new series of metal(II) complexes of Co(II), Ni(II), Cu(II), Zn(II), and Pb(II) have been synthesized from a salen-type Schiff base ligand derived from o-vanillin and 4-methyl-1,2-phenylenediamine and characterized by elemental analysis, spectral (IR, UV-Vis, (1)H NMR, (13)C NMR and EI-mass), molar conductance measurements and thermal analysis techniques. Coats-Redfern method has been utilized to calculate the kinetic and thermodynamic parameters of the metal complexes. The molecular geometry, Mulliken atomic charges of the studied compounds were investigated theoretically by performing density functional theory (DFT) to access reliable results to the experimental values. The theoretical (13)C chemical shift results of the studied compounds have been calculated at the B3LYP, PBEPBE and PW91PW91 methods and standard 6-311+G(d,p) basis set starting from optimized geometry. The comparison of the results indicates that B3LYP/6-311+G(d,p) yields good agreement with the observed chemical shifts. The measured low molar conductance values in DMF indicate that the metal complexes are non-electrolytes. The spectral and thermal analysis reveals that all complexes have octahedral geometry except Cu(II) complex which can attain the square planner arrangement. The presence of lattice and coordinated water molecules are indicated by thermograms of the complexes. The thermogravimetric (TG/DTG) analyses confirm high stability for all complexes followed by thermal decomposition in different steps.
一个新的系列的金属（ii）配合物的 co（ii），ni（ii），cu（ii），zn（ii），和 pb（ii）已经从合成的水杨醛型席夫碱配体衍生自邻香草醛和 4-甲基-1,2-苯二胺和元素分析，光谱（红外，紫外可见，（1）hnmr，（13）cnmr 和 ei-质量），摩尔电导率测量和热分析技术。已采用 coats-redfern 法计算金属配合物的动力学和热力学参数。用密度泛函理论（df t）对所研究化合物的分子几何形状和 mulliken 原子电荷进行了理论研究，以获得与实验值可靠的结果。在优化几何结构的基础上，用 b3lyp、pbepbe 和 pw91pw91 方法计算了所研究化合物的理论（13）c 化学位移值。结果表明，b3lyp/6-311+g（d，p）与观察到的化学位移值吻合较好。在 dmf 中测量的低摩尔电导率值表明金属配合物是非电解质。光谱和热分析表明，所有配合物都具有八面体几何形状，除了 cu（ii）配合物可以达到正方形规划排列。配合物的热图谱表明存在晶格和配位水分子。热重（tg/dtg）分析证实所有配合物都具有很高的稳定性，随后在不同步骤中进行热分解。
