Manuscript Title A Key Cu(II)2(μ-OH)2 Core Structure Preorganized by N 6-Dinucleating Ligand for the Catalytic Alkane Oxidation with H2O2

The catalytic activity of [Cu2(Budpa2)(ClO4)2](ClO4)2 (1), [Cu2(Biphdpa2)](ClO4)4 (2), and [Cu2(OH)2(Biphdpa2)](ClO4)2 (3) in the oxidation of cyclohexane with H2O2 were examined to clarify roles of a Cu2(μ-OH)2 core structure. Budpa2 and Biphdpa2 are N6-hexadentate dinucleating ligands, in which two dpa tridentate donors are linked by 1,4-butyl and 3,3’-dimethylbiphenyl tethers, respectively. 2 and 3 showed higher catalytic activity than 1. The crystal structures, spectroscopic studies, and detailed reaction analyses revealed that a Cu(II)2(μ-OH)2 core is a key structure for the formation of a Cu(III)2(μ-O)2 reaction intermediate to enhance the catalytic activity in the alkane oxidation with H2O2.