Solvent-Induced Isomeric Cu13 Nanoclusters: Chlorine to Copper Charge Transfer Boosting Molecular Oxygen Activation in Sulfide Selective Oxidation

Isomers with minimal structural dissimilarities are promising research objects to obtain a comprehensive understanding of structure-property relationships; however, comparability of isomeric structures is a prerequisite. Herein, two quasi-structurally isomeric 13-nuclei copper nanoclusters (Cu NCs) (Cu13a and Cu13b) containing highly similar Cu13 kernels and different arrangements of peripheral ligands were obtained using a solvent-induced strategy. The exotic chloride ion is shown to play a prominent role in inducing the selective formation of two quasi-isomers, where the comparative study to establish a structure-property relationship was realized. Due to the charge transition from chlorine to the copper core (X(Cl)M(Cu)CT), the molecular oxygen activation of Cu13a showed higher singlet oxygen (1O2) and lower superoxide radical (O2•-) yields compared to those of Cu13b, which gives it better catalytic selectivity for the 1O2 involved selective oxidation of sulfides. The present work not only offers a controllable strategy for the rational design and synthesis of quasi-structurally isomeric Cu NCs but also provides a pathway to boost catalytic selectivity by a halogen to metal core charge transition.