Spectroscopic Characterization and Biological Activity of Salicylaldehyde Thiazolyl Hydrazone Ligands and their Metal Complexes

Design of New Schiff-Base Copper(II) Complexes: Synthesis, Crystal Structures, DFT Study, and Binding Potency toward Cytochrome P450 3A4

We report the synthesis and crystal structures of three new copper(II) Schiff-base complexes. The complexes have been characterized by elemental analysis and Fourier transform infrared (FT-IR) and UV-visible spectroscopies. The X-ray diffraction (XRD) analysis reveals that complexes 1 and 3 crystallize in a monoclinic space group C2/c and 2 in a triclinic space group P1̅, each adopting a square planar geometry around the metal center. We use a density functional theory method to explore the quantum chemical properties of these complexes. The calculation proceeds with the three-dimensional (3D) crystal structure characterization of the complexes in which the calculated IR and UV-vis values are comparable to the experimental results. Charge distribution and molecular orbital analyses enabled quantum chemical property prediction of these complexes. We study the drug-likeness properties and binding potentials of the synthesized complexes. The in silico outcome showed that they could serve as permeability-glycoprotein (P-gp) and different cytochrome P450 substrates. Our calculations showed that the complexes significantly bind to cytochrome P450 3A4.

Coordination and biological behaviour of 2-(p-toluidino)-N'-(3-oxo-1,3-diphenylpropylidene) acetohydrazide and its metal complexes

A series of Ni(II), Co(II), Cu(II), Mn(II), Zn(II), Zr(IV), Fe(III), Ru(III), La(III), Hf(IV) and U(VI) complexes of 2-( p-toluidino)-N'-(3-oxo-1,3-diphenylpropylidene) acetohydrazide (H2L) have been synthesised and characterised by elemental and thermal analyses (DTA, TG), molar conductances, magnetic moments, IR, 1H NMR, UV-Vis spectra and ESR measurements. The ESR spectra of solid complexes [(L)(HL)Cu2(OAc)], [Cu(HL)(H2L)(NO3)] and [CuCl (HL)(H2L)].H2O at room temperature show axial symmetry with covalent bond character, and complex [FeCl2(HL)(H2O)] has gav = 4.38, indicating a high spin (5/2) iron(III) complex. However, complexes [(HL)Mn2Cl3(H2O)4] and [RuCl2(HL)(H2O)].H2O have isotropic spectra consistent with octahedral structure. The antifungal and antibacterial activities of the ligand and its complexes were investigated.

Synthesis, magnetic, spectral and antimicrobial studies on metal complexes of 4-methylphenylaminoacetoisatin hydrazone

A new series of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Cr(III), Fe(III) and Cu(I) complexes of 4-methylphenylaminoacetoisatin hydrazone (HL) have been prepared and characterised The IR spectral data of the complexes indicate neutral bidentate, neutral tridentate or monobasic tridentate behaviour of the ligand depending on the metal ion. The ESR spectra of the complexes [Cu(OAc) (L)].0.5H2O, [CuCl(L)].0.5H2O, [Cr(Cl)(OH)2(HL)].0.5H2O, Co(NO3)2[(HL)2].2.5H2O and [(HL)(Mn)3(Cl)4(OH)2(H2O)6].H2O, are isotropic. However, those of [Cu(NO3)(L)].2.5H2O and [Cu(SO4)(H2O)(HL)], are anisotropic with ionic bond characters. The antibacterial and antifungal activities of the compounds show that some metal complexes exhibit a greater inhibitory effect than tetracycline (bacteria) and amphotricine (fungi).

First raw transition metal complexes of salicylidene and 2-hydroxy-1-naphthylidene-N-cyanoacetohydrazone

Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of salicylidene-N-cyano-acetohydrazone H2L1 and 2-hydroxy-l-naphthylidene-N-cyanoacetohydrazone H2L2 have been prepared in ethanolic solution and characterized by analytical, spectral, magnetic susceptibility, molar conductivity and TGA measurements. The analytical data show that all the complexes derived from H2L1 and H2L2 are formed in molar ratios 1M:2L, except the complexes of Mn(II), Co(II) and Cu(II) acetates of H2L2 and the complexes of Mn(II), Co(II) and Ni(II) acetates and CuCl2 of H2L1 are formed in 1:1 molar ratios. The conductance data show that all metal complexes are non-electrolytes. Electronic absorption spectra and magnetic susceptibility measurements proved that the prepared complexes have octahedral configuration except [Co(HL2)OAc] which has tetrahedral structure. The ligand field parameters were calculated for the Co(II) and Ni(II) complexes and the data show that the covalent character of the metal ligand sigma-bond is low. The ESR parameters of the Cu(II) complexes at room temperature were calculated. Thermal TGA for some solid complexes are reported.

Synthesis, spectroscopic characterization and biological activity of the metal complexes of the Schiff base derived from phenylaminoacetohydrazide and dibenzoylmethane

A new series of mono and binuclear Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), La(III), Ru(III), Hf(IV), ZrO(II) and UO2(II) complexes of phenylaminodibenzoylhydrazone have been synthesized and characterized by elementals analyses, IR UV-vis spectra, magnetic moments, conductances, thermal analyses (DTA and TGA) and electron spin resonance (ESR) measurements. The IR spectral data show that, the ligand behaves as a neutral bidentate type (15 and 16), monobasic bidentate type (6), or monobasic tridentate type (5, 7, 8, 10, 11, 13, 14, 17-21) or dibasic tridentate type 2-4, 9 and 12 towards the metal ion. Molar conductances in DMF solution indicate that, the complexes are non-electrolytes. The ESR spectra of solid complexes (9 and 10) show axial and non-axial types indicating a d(x2-y2) ground state with significant covalent bond character. However, complexes (11 and 12), show isotropic type, indicating manganese(II) octahedral geometry. Antibacterial and antifungal tests of the ligand and its metal complexes are also carried out and it has been observed that the complexes are more potent bactericides and fungicides than the ligand.