Synthesis, thermal, spectral, and biological properties of zinc(II) 4-aminobenzoate complexes

• Published in: Journal of thermal analysis and calorimetry 2017-08, Vol.129 (2), p.1065-1082
• Main Authors: Homzová, Katarína, Győryová, Katarína, Hudecová, Daniela, Koman, Marián, Melník, Milan, Kovářová, Jana
• Format: Article
• Language: English
• Subjects: Aminobenzoate potassium; Analytical Chemistry; Aniline; Antiinfectives and antibacterials; Antimicrobial agents; Argon; Bacteria; Biological properties; Caffeine; Carbon dioxide; Carbon monoxide; Chemistry; Chemistry and Materials Science; Complex compounds; Crystal structure; Decomposition; Distortion; Escherichia coli; Fungi; Infrared radiation; Infrared spectroscopy; Inorganic Chemistry; Ligands; Measurement Science and Instrumentation; Niacinamide; Physical Chemistry; Polymer Sciences; Spectroscopic analysis; Synthesis; Thermal analysis; Thermal decomposition; X-ray diffraction; Zinc compounds; Zinc oxide
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-017-6184-9

New zinc(II) 4-aminobenzoate complex compounds with general formula [Zn(4-NH 2 benz) 2 L 2 ]· n H 2 O, where 4-NH 2 benz = 4-aminobenzoate; L = nicotinamide (nad), isonicotinamide (inad), N -methylnicotinamide (mnad), thiourea (tu), urea (u), theophylline (tph), and caffeine (caf); n  = 0–2; were synthesised and characterised by elemental analysis, thermal analysis, and IR spectroscopy. The thermal behaviour of prepared compounds was studied by TG/DTG and DTA methods in argon atmosphere. During the thermal decomposition, organic ligand, carbon monoxide, carbon dioxide, and aniline were evolved. The final solid product of the thermal decomposition was zinc oxide. The volatile gaseous products were proved by mass spectrometry. Solid intermediate product and the final product of thermal decomposition were identified by IR spectroscopy and X-ray powder diffraction method. It was solved crystal structure of polymeric [Zn(4-NH 2 benz) 2 ], where the coordination environment around zinc(II) atom is an unsymmetrical distorted trigonal bipyramidal with chromophore ZnO 3 N 2 . The antimicrobial activity of zinc(II) carboxylate compounds was tested against various strains of bacteria, yeasts, and filamentous fungi ( S. aureus , E. coli , C. albicans , R. oryzae , A. alternata , M. gypseum ). The presence of zinc in complexes led to the increase their antimicrobial activity in comparison with free 4-aminobenzoic acid and ligands.