Mimicking the Cu Active Site of Lytic Polysaccharide Monooxygenase Using Monoanionic Tridentate N‑Donor Ligands

In an effort to prepare small molecule mimics of the
active site
of lytic polysaccharide monooxygenase (LPMO), three monoanionic tridentate
N donor ligands comprising a central deprotonated amide group flanked
by two neutral donors were prepared, and their coordination chemistry
with Cu­(I) and Cu­(II) was evaluated. With Cu­(I), a dimer formed, which
was characterized by X-ray crystallography and NMR spectroscopy. A
variety of mononuclear and dinuclear Cu­(II) species with a range of
auxiliary ligands (MeCN, Cl–, OH–, OAc–, OBz–, CO32–) were prepared and characterized by X-ray diffraction
and various spectroscopies (UV–vis, EPR). The complexes exhibit
structural similarities to the LPMO active site.