Experimental and theoretical investigations of copper (I/II) complexes with triazine-pyrazole derivatives as ligands and their in situ C-N bond cleavage

Two copper complexes, Cu(SCN)(MpzT-(EtO)) (1) (MpzT-(EtO) = L3) and CuCl(HO)(MpzT-O) (2) (MpzT-O = L4) were synthesized by the reaction of 2,4,6-tri(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine (L1) or 2,4,6-tri(1H-pyrazol-1-yl)-1,3,5-triazine (L2) with CuCl·2HO in anhydrous ethanol and methanol, respectively. The complexes were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single crystal X-ray diffraction and X-ray powder diffraction. The structural characterizations and quantum mechanical calculations of the two complexes were analyzed in detail. It was found that an in site reaction occurred during the synthesis process of complexes 1 and 2, likely due to catalytic property of copper ions which leads to the C-N bond cleavage to generate new organic species, namely, MpzT-(EtO) (L3) and MpzT-O (L4)