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

Two novel bidentate Schiff base ligands, 2-(2-hydroxy-3,5-dichloro/diboromo) benzaldehyde-[4-(3-methyl-3-mesitylcyclobutyl)-1,3-thiazol-2-yl]hydrazone, L¹H, L²H and their transition metal complexes are reported. The new ligands and their complexes have been characterized by elemental analyses, Λ_M, infrared, u.v.–vis, ¹H- and ¹³C-n.m.r. spectroscopy, and magnetic susceptibility measurements. The thermal properties of all complexes have been investigated by TG technique. The complexes contain two monoanionic, bidentate NO ligands. It was found that all the complexes are mononuclear. Antimicrobial activities of the ligands and their complexes have been tested against five different microorganisms, and some of the complexes were found to be active against some of the microorganisms studied.     

New Route to Synthesis of Unexpected Pyridoin Derivatives: Their Structure Determination with Spectroscopic and X-Ray Methods

The new 1,2,4-triazine-3-thione derivatives were obtained by a new route using a one-step process. The structure of the compounds was determined with infrared (IR), ¹H NMR, and ¹³C NMR spectroscopic methods and elemental analysis. A representative x-ray crystallographic analysis of 3 was given, and its x-ray data are discussed in detail. This is a facile procedure and shorter than earlier methods.     

An experimental and theoretical approach to the molecular structure of 3‐{[4‐(3‐Methyl‐3‐phenyl‐cyclobutyl)‐thiazol‐2‐yl]‐hydrazono}‐1,3‐dihydro‐ indol‐2‐one

The title molecule, 3‐{[4‐(3‐methyl‐3‐phenyl‐cyclobutyl)‐thiazol‐2‐yl]‐hydrazono}‐1,3‐dihydro‐indol‐2‐one (C₂₂H₂₀N₄O₁S₁), was prepared and characterized by ¹H NMR, ¹³C NMR, IR, UV–visible, and single‐crystal X‐ray diffraction. The compound crystallizes in the monoclinic space group P21 with a = 8.3401(5), b = 5.6976(3), c = 20.8155(14) Å, and β = 95.144(5)°. Molecular geometry from X‐ray experiment and vibrational frequencies of the title compound in the ground state has been calculated using the Hartree–Fock with 6‐31G(d, p) and density functional method (B3LYP) with 6‐31G(d, p) and 6‐311G(d, p) basis sets, and compared with the experimental data. The calculated results show that optimized geometries can well reproduce the crystal structural parameters, and the theoretical vibrational frequencies values show good agreement with experimental data. Density functional theory calculations of the title compound and thermodynamic properties were performed at B3LYP/6‐31G(d, p) level of theory. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012     

Salicylaldehyde thiazolyl hydrazones as ligands

Novel bidentate Schiff base ligands, 2‐(2‐hydroxy‐5‐chloro/nitro)benzaldehyde‐[4‐(3‐methyl‐3‐mesitylcyclobutyl)‐1,3‐thiazol‐2‐yl]hydrazone, and their metal complexes have been prepared and characterized by elemental analyses, IR, ¹³C and ¹H NMR spectra, and magnetic susceptibility measurements. All the complexes were found to be mononuclear. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:617–621, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10201     

Structure of 2-{2-[3-methyl-3-(2,4,6-trimethylphenyl) cyclobutyl]-2-oxoethyl}isoindole-1,3-dione

2-{2-[3-Methyl-3-(2,4,6-trimethylphenyl)cyclobutyl]-2-oxoethyl}isoindole-1,3-dione (C₂₄ H₂₅NO₃) was synthesized, and its crystal structure was determined by X-ray crystallographic techniques. The compound crystallizes in the triclinic space group P-1, with unit cell parameters: a = 14.109(9) Å, b = 14.130(8) Å, c = 12.152(6) Å, = 105.62(5)°, = 113.75(4)°, = 98.78(5)°, V = 2039.8(19) ų, D _c= 1.223 g/cm³, and Z = 4. The crystal structure has two crystallographically independent molecules, I and II. These molecules are held together by weak intermolecular C—H···O interactions, forming a continuous chain. The dihedral angles between the N-substituted phthalimide moiety and cyclobutane ring in molecules I and II are 60.37(14) and 68.18(18)°, respectively.     

Highly sensitive sensing of zinc(II) by development and characterization of a PVC-based fluorescent chemical sensor

A sensor membrane with excellent performance based on 1-methyl-1-phenyl-3-[1-hydroxyimino-2-(succinimido)ethyl]cyclobutane has been developed for the determination of zinc(II) ions. The sensing membrane is capable of determining zinc(II) with an outstanding high selectivity over a dynamic range between 8.0×10(-8) and 1.6×10(-4) mol L(-1) with a limit of detection of 2.5×10(-8) mol L(-1) (1.6 μg L(-1)). It can be easily and completely regenerated by using 0.1 mol L(-1) EDTA solution. The optical sensor developed here was found to be stable, cost effective, easy to prepare, and has unique selectivity towards Zn(2+) ion with respect to common metal ions. The proposed sensor was then applied for the determination of zinc in tap water and hair samples with satisfactory results.     

Experimental and quantum chemical calculational studies on N‐[4‐(3‐Methyl‐3‐phenyl‐cyclobutyl)‐thiazol‐2‐yl]‐N′‐pyridin‐3ylmethylene‐hydrazine

The title molecule, N‐[4‐(3‐Methyl‐3‐phenyl‐cyclobutyl)‐thiazol‐2‐yl]‐N′‐pyridin‐3ylmethylene‐ hydrazine (C₂₀ H₂₀ N₄ S₁), was characterized by ¹H‐NMR, ¹³C‐NMR, IR, UV‐visible, and X‐ray determination. In addition to the molecular geometry from X‐ray experiment, the molecular geometry, vibrational frequencies and gauge including atomic orbital ¹H‐ and ¹³C‐NMR chemical shift values of the title compound in the ground state have been calculated using the Hartree‐Fock and density functional method (B3LYP) with 6‐31G(d, p) basis set. The calculated results show that optimized geometries can well reproduce the crystal structural parameters. By using time‐dependent density functional theory method, electronic absorption spectrum of the title compound has been predicted. © 2011 Wiley Periodicals, Inc.     

1‐Methyl‐1‐phenyl‐3‐[1‐hydroxy­imino‐2‐(succinimido)­ethyl]­cyclo­butane

In the title compound, C₁₇H₂₀N₂O₃, the cyclo­butane ring is puckered, with a dihedral angle of 19.11 (15)°. The 1‐phenyl and 3‐[1‐hydroxy­imino‐2‐(succinimido)­ethyl] groups are in cis positions. The mol­ecules are linked by O—H⋯O and C—H⋯π(benzene) interactions, forming a two‐dimensional network.     

Preparation,molecular definition,spectroscopic characterization and density functional theory calculations on N’-(4-(3-methyl-3-phenylcyclobutyl)-3-phenylthiazol-2(3H)-ylidene)benzenesulfonohydrazide

Abstract

A new sulfonyl derivative (C₂₆H₂₅N₃O₂S₂), N’-(4-(3-methyl-3-phenylcyclobutyl)?3-phenylthiazol-2(3H)-ylidene)benzenesulfonohydrazide, was prepared from a mixture of benzenesulfonylhydrazide and phenylisothiocyanate in ethanol. The 3?D crystal structure, unit-cell dimensions, space group and crystal system of compound were investigated by single-crystal X-ray diffraction (SCXRD). FT-IR spectrum in solid state was observed in the region 4000–400?cm^?1 and the ¹H and ¹³C NMR spectra were recorded in CDCl₃ solution. In order to support the experimental results, the molecular geometry, vibrational frequencies, ¹H and ¹³C chemical shifts in the ground state have been calculated by using the density functional method (DFT/B3LYP) together with 6-311?G+(d, p) basis set. A good linear correlation between experimental and theoretically predicted structural and spectral parameters was observed (R²～0.9).     

Synthesis,characterization and antimicrobial activity of the Schiff bases derived from 2,4-disubstituted thiazoles and 3-methoxysalicylaldehyde,and their cobalt(II), copper(II), nickel(II) and zinc(II) complexes

Two new Schiff base ligands containing 2,4–disubstituted thiazoles and cyclobutane rings, 4-(1-methyl-1-phenylcyclobutane-3-yl)-2-(2-hydroxy-3-methoxybenzylidenehydrazino)thiazole (L¹H), 4-(1-methyl-1-p-xylylcyclobutane-3-yl)-2-(2-hydroxy-3-methoxybenzylidenehydrazino)thiazole (L²H) and their mononuclear complexes with a 1:2 metal–ligand ratio have been prepared from acetate salts of Co^II, Cu^II, Ni^II and Zn^II in EtOH. The authenticity of the ligands and their complexes have been established by microanalyses, i.r., ¹³C- and ¹H-n.m.r. spectra, and by magnetic susceptibility and conductivity measurements. The complexes are mononuclear. Thermal properties of the ligands and complexes have been studied by t.g.a. and d.s.c. techniques. Antimicrobial activities of the ligands and their complexes have been tested against six different microorganisms; three are yeast and three are bacteria. One of the ligands and many of the complexes were found to be active against some of the microorganisms studied.