Search

A calcium complex of N-phthaloylglycine (CaNPG) has been synthesized, and its crystal structure has been characterized by X-ray diffraction method. The FT-IR and fluorescence spectra for CaNPG have been recorded. N-phthaloylglycine ligand coordinates to Ca ion through the carboxylate O atoms as a bidentate ligand, and Ca ion does not play an important role in florescence spectrum. In order to support experimental findings and also investigate molecular surfaces, natural bond orbital (NBO) and nonlinear optical (NLO) optical properties of CaNPG complex, density functional theory calculations have been performed by hybrid B3LYP level. The very small energy gap between α-spin frontier molecular orbitals (FMOs) is demonstrated that CaNPG is a very reactive, chemically soft and optically active complex. The high stabilization energies of hyperconjugative interactions are also demonstrate that the charge mobility in CaNPG is very high. As consistent with above findings, first static hyperpolarizability of CaNPG has been found to be 10 times higher than pNA which is a NLO material. [ABSTRACT FROM AUTHOR]

• Synthesis of mono- and bis-Schiff base ligands of 3,5-diamino-1,2,4-triazole along with their transition metals complexes. • Experimental (IR, UV-Vis, 1HNMR, 13CNMR, ESI-MS) and computational characterization at B3LYP/6-311G(d.p) was done. • Thermal stability and fluorescence properties of compounds were evaluated. • In vitro evaluation of the synthesized ligands and their corresponding 3 d -metal complexes against five pathogenic bacterial species. • Enzyme inhibitory evolution of compounds against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The aim of this project was to introduce novel bioactive compounds through the design and synthesis of two mono-Schiff bases, 4- [(5-amino-1H-1,2,4-triazol-3-yl)imino]methylbenzene-1,3-diol (L1) and 2- [(5-amino-1H-1,2,4-triazol-3-yl)imino]methyl}-6-methoxyphenol (L2) and one bis-Schiff base, 2,2′-{1H-1,2,4-triazole-3,5-diylbis [nitrilomethylylidene]}bis(6-methoxyphenol) (L3) together with their complexes of transition metals [VO(IV), Cr(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)]. The molecular structures of as-synthesized Schiff bases were explicitly confirmed by physical, spectral, analytical and computational studies. Quantum chemical calculations based on density functional theory (DFT) were performed at B3LYP/6-311+G(d.p) level to explore the optimized geometrical structures, molecular electrostatic potential (MEP), Mulliken atomic charges (MAC) and frontier molecular orbital (FMO) analysis of the as-synthesized ligands. The FMO energy gaps were rationalized to be 0.162, 0.158 and 0.138 eV for ligands (L1), (L2) and (L3) , respectively which can efficiently polarize their chemical structures. As-synthesized metal complexes have good agreement with their purposed structures with octahedral geometry except vanadium complexes, which have square pyramidal geometry. As-synthesized compounds were also evaluated through thermogravimetry and fluorescence analysis. Additionally, the compounds were also scrutinized for antibacterial activity against five bacterial strains (Halomonas halophila, Chromohalobacter israelensis, Escherichia coli, Chromohalobacter salexigens and Halomonas salina) and enzyme inhibition bioassay against butyrylcholinesterase (BChE) and acetylcholinesterase (AChE). The results showed that the complexes (15) and (1) were the most active inhibitors of BChE and AChE enzymes with 94.60% and 90.90% activity, respectively. Moreover, all the compounds also exhibited significant antibacterial activity. It has been found that the metal complexes displayed more biological activity in contrary to parent ligands as a result of chelation. [Display omitted] [ABSTRACT FROM AUTHOR]