One-Pot Synthesis and Characterization of Biomimetic Copper(I) Complexes

A modular one-pot synthesis yielding tetracoordinated-N,N,N,N-copper(I) complexes bearing imine and diimine ligands was developed. Copper aids the condensation of a pyridine or imidazole carbaldehyde with a biphenyl amine and even stabilizes labile ligands. Tetradentate and bidentate ligands were formed, the latter forming homoleptic CuL2 complexes. The identity and purity of the compounds were assessed by NMR, elemental analysis and mass spectrometry. The interconversion of different species in solution was studied by variable temperature NMR. The complexes aim to mimic the histidine copper brace of lytic polysaccharide monooxygenases (LPMOs) and bond lengths obtained from XAS and single crystal XRD for the complexes were compared to reported photoreduced LPMOs.