Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
Department of Chemistry, RCU Government Post Graduate College, Uttarkashi 249193, India.
Inorg Chem. 2020 Aug 17;59(16):11417-11431. doi: 10.1021/acs.inorgchem.0c01195. Epub 2020 Jul 28.
Five novel zinc(II) and cadmium(II) β-oxodithioester complexes, [Zn()] (), [Zn()] (), [Zn()] () [Cd()] (), [Cd()] (), with β-oxodithioester ligands, where = 3-(methylthio)-1-(thiophen-2-yl)-3-thioxoprop-1-en-1-olate, = 3-(methylthio)-1-(pyridin-3-yl)-3-thioxoprop-1-en-1-olate, and = 3-(methylthio)-1-(pyridin-4-yl)-3-thioxoprop-1-en-1-olate, were synthesized and characterized by elemental analysis, IR, UV-vis, and NMR spectroscopy (H and C{H}). The solid-state structures of all complexes were ascertained by single-crystal X-ray crystallography. The β-oxodithioester ligands are bonded to Zn(II)/Cd(II) metal ions in an OS and N chelating/chelating-bridging fashion leading to the formation of 1D (in -) and 2D (in ) coordination polymeric structures, but complex was obtained as a discrete tetrahedral molecule. Complex crystallizes in the 2 chiral space group and has been studied using circular dichroism (CD) spectroscopy. The multidimensional assemblies in these complexes are stabilized by many important noncovalent C-H···π (ZnOSC, chelate), π···π, C-H···π, and H···H interactions. The catalytic activities of - in reactions involving C-C and C-O bond formation have been studied, and the results indicated that complex can be efficiently utilized as a heterogeneous bifunctional catalyst for the Knoevenagel condensation and multicomponent reactions to develop biologically important organic molecules. The luminescent properties of complexes were also studied. Interestingly, zinc complexes - showed strong lumniscent emission in the solid state, whereas cadmium complexes and exhibited bright luminescent emission in the solution phase. The semiconducting behavior of the complexes was studied by solid-state diffuse reflectance spectra (DRS), which showed optical band gaps in the range of 2.49-2.62 eV.
五种新型锌(II)和镉(II)β-氧代二硫代酯配合物，Zn()，Zn()，Zn()，Cd()，Cd()，配体为β-氧代二硫代酯，其中 = 3-(甲基硫代)-1-(噻吩-2-基)-3-硫代丙烯-1-醇酸酯， = 3-(甲基硫代)-1-(吡啶-3-基)-3-硫代丙烯-1-醇酸酯， = 3-(甲基硫代)-1-(吡啶-4-基)-3-硫代丙烯-1-醇酸酯，通过元素分析、红外、紫外可见和 NMR 光谱（H 和 C{H}）合成并进行了表征。所有配合物的固态结构均通过单晶 X 射线晶体学确定。β-氧代二硫代酯配体以 OS 和 N 螯合/螯合桥接方式与 Zn(II)/Cd(II)金属离子键合，导致形成 1D（在 -）和 2D（在 ）配位聚合物结构，但配合物 则作为离散的四面体形分子获得。配合物 在 2 个手性空间群中结晶，并使用圆二色性（CD）光谱进行了研究。这些配合物中的多维组装通过许多重要的非共价 C-H···π（ZnOSC，螯合）、π···π、C-H···π 和 H···H 相互作用得到稳定。还研究了 - 在涉及 C-C 和 C-O 键形成的反应中的催化活性，结果表明配合物 可以有效地用作多相双功能催化剂，用于 Knoevenagel 缩合和多组分反应，以开发具有重要生物意义的有机分子。还研究了配合物的发光性质。有趣的是，锌配合物 - 在固态下表现出强烈的发光发射，而镉配合物 和 则在溶液相中表现出明亮的发光发射。通过固态漫反射光谱（DRS）研究了配合物的半导体行为，其光学带隙范围为 2.49-2.62 eV。
