Synthesis, Structures, and Reactivity of Copper(I) Complexes Supported by a Rigid Dinucleating Ligand

Abstract

Abstract Herein, we report the diverse Cu I chemistry of a dinucleating ligand L that features two iminopyridine chelates bridged by a 1,8‐diaminoxanthene linker {L = (1 E ,1′ E )‐ N , N′ ‐(2,7‐di‐ tert ‐butyl‐9,9‐dimethyl‐9 H ‐xanthene‐4,5‐diyl)bis[1‐(pyridin‐2‐yl)methanimine]}. The ligand L leads to the formation of discrete bimetallic species, or metallopolymers, as a result of syn ‐parallel or anti ‐parallel mutual disposition of the chelating units. The reaction of L with [Cu(NCMe) 4 ] + forms the discrete bimetallic complexes [Cu 2 (L)(NCMe) 2 ] 2+ ( 1 ) or [Cu 2 (L) 2 ] 2+ ( 2 ), depending on the solvent and the ligand‐to‐metal ratio. In contrast, the reaction of L with CuX (X = Cl, Br) forms the metallopolymers [Cu 2 (L)(Br) 2 ] n ( 3 ) and {[Cu 3 (L) 2 Cl 2 ][CuCl 2 ]} n ( 4 ). The compounds were characterized by X‐ray crystallography, NMR spectroscopy, mass spectrometry, electrochemistry, and DFT calculations. The reaction of compound 1 with O 2 in CH 2 Cl 2 was found to lead to a mixture of Cu II products of which tetrametallic [Cu 4 (L) 4 (OH) 3 (Cl)] 4+ and [Cu 4 (L) 2 (OH) 4 ] 4+ were identified by X‐ray crystallography.