School of Chemistry, University of Hyderabad, Hyderabad-500 046, India.
Department of Chemistry, Thiagarajar College of Engineering, Madurai-625015, India.
Dalton Trans. 2022 Nov 1;51(42):16307-16315. doi: 10.1039/d2dt02657k.
A new class of double stranded dinuclear monohelicates, -[{Re(CO)-(μ-L)-Re(CO)}L] (1-4), were self-assembled from Re(CO), a rigid bischelating donor (H-L: 1,4-dihydroxybenzoquinone (H-dhbq) for 1 and 3; 2,5-pyrazine dicarboxylic acid (H-pydc) for 2 and 4) and a flexible bis(monodentate) pyrazolyl N donor L (L = bis(4-((pyrazolyl)methyl)phenyl)methane for 1 and 2; L = bis(4-((pyrazolyl)methyl)phenyl)methanone for 3 and 4) in mesitylene. Metallomacrocycle 1 was confirmed by single crystal X-ray crystallography. Although these helicates contain two organic ligand strands, only one strand is arranged in a helical fashion, which is an unprecedented form in the helicate architecture. The molecular structures of 1-4 as helicates and mesocates were optimized using DFT methods. The dynamic interconversion of the metallomacrocycles in solution was studied by H NMR studies. The photophysical properties of 1-4 were studied experimentally and the nature of electronic transitions was determined by TD-DFT analysis. Quinonoid motif-based complexes 1 and 3 displayed strong visible light absorption. The redox properties of 1-4 were studied using cyclic voltammetry.
一类新型的双链双核单螺旋配合物， -[{Re(CO)-(μ-L)-Re(CO)}L] (1-4)，由 Re(CO)、刚性双螯合给体（H-L：1,4-二羟基苯醌（H-dhbq）用于 1 和 3；2,5-吡嗪二甲酸（H-pydc）用于 2 和 4）和柔性双（单齿）吡唑基 N 供体 L（L = 双（4-((吡唑基)甲基)苯基)甲烷用于 1 和 2；L = 双（4-((吡唑基)甲基)苯基)甲酮用于 3 和 4）在均三甲苯中自组装而成。金属大环配合物 1 通过单晶 X 射线晶体学得到证实。尽管这些螺旋配合物含有两个有机配体链，但只有一个链呈螺旋排列，这在螺旋配合物结构中是前所未有的形式。使用 DFT 方法优化了 1-4 作为螺旋配合物和介晶的分子结构。通过 H NMR 研究研究了溶液中金属大环配合物的动态互变。实验研究了 1-4 的光物理性质，并通过 TD-DFT 分析确定了电子跃迁的性质。基于醌式基序的配合物 1 和 3 显示出强烈的可见光吸收。使用循环伏安法研究了 1-4 的氧化还原性质。
