Self-Assembly of Neutral Platinum-Based Supramolecular Ensembles Incorporating Oxocarbon Dianions and Oxalate

Five neutral platinum-based macrocycles incorporating cyclic oxocarbondianions, squarate and croconate and their
acyclic analogue, oxalate, have been synthesized in 90−95% yield via self-assembly. The combination of the
diplatinum molecular clip with all three dianions afforded molecular rectangles, whereas a platinum-based 60°
acceptor unit produced a supramolecular rhomboid with croconate ion but a triangle with squarate ion. In all cases,
multinuclear NMR spectra were consistent with the formation of single highly symmetrical species. The three
rectanglular and the rhomboid assemblies were characterized by single-crystal X-ray crystallography. The triangular
species was characterized by FAB mass spectrometry.

通过自组装过程以90%~95%的收率合成了五种中性铂基大环化合物，该类化合物涵盖环状氧碳二阴离子、方酸根（squarate）与克酮酸根（croconate），以及它们的非环状类似物草酸根（oxalate）。将双铂分子夹与上述三种二阴离子结合，均可得到分子矩形组装体；而采用铂基60°受体单元时，与克酮酸根配位可生成超分子斜方菱形结构，与方酸根配位则得到三角形组装体。所有体系的多核核磁共振（NMR）光谱均证实仅生成了单一的高度对称物种。三种矩形组装体与斜方菱形组装体均通过单晶X射线衍射（single-crystal X-ray crystallography）完成了结构表征，而三角形组装体则通过快原子轰击（FAB）质谱完成了结构表征。