Synthesis and characterization of a copper (II) compound with a new N3Py2 core ligand: Influence of methyl substitution on structural parameters and catalytic mimicking activity

A mononuclear copper (II) compound [Cu(L1)](ClO4)2 1 containing nonheme N3Py2 pentadentate ligand N1,N3-dimethyl-N1-(3-(methyl(pyridin-2-ylmethyl)amino)propyl)-N3-(pyridin-2-ylmethyl)propane-1,3-diamine) have been synthesized and characterized by several methods. A new ligand L1 has been prepared by methylation of secondary -NH of L2 (N1-(pyridin-2-ylmethyl)-N3-(3-((pyridin-2-ylmethyl)amino)propyl)propane-1,3-diamine) at and characterized by NMR spectroscopy. Compound 1 has been characterized by single-crystal X-ray crystallography and spectroscopic techniques. It crystallizes in a centrosymmetric space group P21/n and adopts a distorted square-pyramidal geometry with τ5= 0.13. We also prepared compound [Cu(L2)](ClO4)2 2, and its structural properties were compared with 1. The geometry of 1 is nearly SP, while compound 2 is intermediate between SP and TBP. We then investigated the applications of 1 and 2 in phenoxazinone synthase and catecholase activity. The results suggest compound 1 was more effective in both activities than 2.