DEVELOPMENT NEW COPPER COMPLEXES WITH PHENANTHROLINE DERIVATIVES AND ISONIAZID
Copper complexes. Imidazole derivatives. Isoniazid.
The imidazole derivatives of 1-10-phenanthroline-5,6-dione (phend) have biological properties, such as DNA cleavage, antitumor and antibacterial, in addition, synthetic versatility allows the inclusion of groups that enhance their characteristics biochemical. In this context, the present work aims to synthesize and characterize new copper complexes with phenanthroline derivatives having as additional ligand chlorides and isoniazid (INH). The complexes [Cu(L)Cl2] and [Cu(L)(INH)2]Cl2 were synthesized, where L is phend and the imidazole derivatives obtained from the reaction of phend with 4-cyanobenzaldehyde and 4-nitrobenzaldehyde, named of L-CN and L-NO2 respectively. The ligands and complexes were synthesized from methodologies adapted as base similar compounds described in the literature and characterized by spectroscopic (Uv-Vis, IV and Raman), thermal and electrochemical techniques. From the vibrational spectra were observed the vibrational modes indicative of the phenanthroline system of the L ligands in 810 and 740 cm-1. The Compounds with the phend ligand show C = O stretching around 1690 cm-1 and the complexes with L-CN and L-NO2 exhibited the characteristic stretches of imidazole of these ligands. Infrared of the INH-containing complexes, it was determined that this ligand was coordinated in the bidentate form, due to the displacements of the amide modes I and II compared to the free ligand. The electronic spectra of the compounds in DMSO showed intraligant bands in the region of 260 to 400 nm, for the complexes the transitions d-d in 767, 741 and 732 nm were also observed for [Cu(phend)Cl2] (CuPhenD), [Cu(L-CN)Cl2] (CuLCN) and [Cu(L-NO2)Cl2] (CuLNO2) respectively. Complexes with INH, they presented the d-d bands at 760, 721 and 719 nm for [Cu(phend)(INH)2] Cl2 (CuPNI), [Cu(L-CN)(INH)2]Cl2 (CuCNI)and [Cu(L-NO2)(INH)2]Cl2 (CuNO2I) respectively. Additionally, thermal decomposition and thermal stability of the compounds were observed by the thermal analyzes (TG, DTG and EGA). The cyclic voltammograms of the [Cu(L)Cl2] complexes presented only one redox pair indicative of the Cu2+/Cu+ process, with E1/2 of 262 (CuPhenD), 195 (CuLCN) and 150 mV (CuLNO2). However, of the chlorides by INH it was possible to verify two redox pairs referring to Cu2+/Cu+ and Cu+/Cu0 processes.