Synthesis and Structure of Cu(II) and Zn(II) Coordination Compounds with Tetrafluorophenyl-Substituted Pyrazole Ligands

Mononuclear coordination compounds Cu(L1)2(H2O) (1) and Zn(L2)2·1.41H2O (2) are synthesized by reacting copper(II) or zinc(II) salts with 5-methyl-1-(2,3,5,6-tetrafluorophenyl)-1H-pyrazole-3-carbohydrazide (L). During the synthesis of complex 1, hydrolysis occurs of the C(O)–NH hydrazide bond in initial L with the formation of 5-methyl-1-(2,3,5,6-tetrafluorophenyl)-1H-pyrazole-3-carboxylic acid (HL1), with its anions (L1)– being a part of the complex. The formation of 2 is accompanied by acylation of L, therefore, N′-acetyl-5-methyl-1-(2,3,5,6-tetrafluorophenyl)-1H-pyrazole-3-carbohydrazide is present in the deprotonated form (L2)– as ligands in the structure of the complex. The structures of the synthesized compounds are established by the single crystal X-ray diffraction analysis.