Synthesis, spectroscopic characterization, and antimicrobial activity of cobalt(II) complexes of acetone-N(4)-phenylsemicarbazone: crystal structure of [Co(HL)2(MeOH)2](NO3)2

Synthesis, spectroscopic characterization, density functional theory study, antimicrobial and antioxidant activities of curcumin and alanine-curcumin Schiff base

In this work, a novel Schiff-base derived from curcumin and L-Alanine was synthesized under microwave conditions in excellent yield. The structural characterization has been carried out from their elemental analyses, FTIR, UV-Vis and 13C-NMR and 1H-NMR spectral techniques. The Schiff base (Cur-Ala) and curcumin (Cur) have been screened for their antimicrobial activity toward some pathogens clinically important microorganisms: Bacillus subtilis, Escherichia coli and Staphylococcus aureus, Aspergillus niger and Candida albicans. Result found that the Schiff base was more active than the curcumin. The antibacterial and antifungal activities of Cur-Ala can be attributed to its greatest dipole moment, as shown by theoretical calculations. Also, the antioxidant activity of Schiff base and curcumin were studied by DPPH, cupric ion reducing antioxidant capacity and o-phenanthroline techniques. Results indicate that Cur-Ala and Cur show more antioxidant activities than the standard antioxidants (BHT and BHA). Quantum chemical parameter calculations of Cur-Ala and Cur have been investigated by DFT using B3LYP/6-31G (d,p) basis set method to calculate the optimized structure, atomic charges, MESP, global reactivity descriptors and thermomolecular proprieties of both molecules.Communicated by Ramaswamy H. Sarma.

Stereoselective polymerization of methyl methacrylate and rac-lactide mediated by iminomethylpyridine based Cu(ii) complexes

Iminomethylpyridine based copper(ii) complexes [LnCuCl2] (L_n = LA, LC–LF) and [LBCu(μ-Cl)Cl]2 have been synthesized and characterized.

A Co(ii) complex of a vitamer of vitamin B6acts as a sensor for Hg2+and pH in aqueous media

A new Co(ii) complex was prepared by template reaction, acting as a dual fluorescent sensor for Hg²⁺ions and pH in aqueous solution.

Crystal structure of (E)-2-[(2-hy-droxy-4-meth-oxy-phen-yl)(phen-yl)methyl-idene]-N-phenyl-hydrazine-1-carboxamide

The title compound, C21H19N3O3, has an E conformation about the azomethine double bond. The central moiety of the hydrazinecarboxamide moiety [-N-N-C(=O)-N-] has an almost coplanar arrangement [maximum deviation for the C atom = 0.010 (2) Å]. This central moiety is flanked by three aromatic rings and its mean plane makes dihedral angles of 24.7 (1), 72.91 (12) and 34.26 (11) Å, respectively, with the phenolic ring, the phenyl ring attached to the same C atom as the phenolic ring, and the phenyl-hydrazine ring. The adjacent phenolic and phenyl rings are twisted away from each other to reduce steric hindrance and make a dihedral angle of 80.59 (12)°. The phenolic and phenyl-hydrazine rings are inclined to one another by 28.89 (11)°. The rigidity of the mol-ecule is increased by an intra-molecular O-H⋯N hydrogen bond involving the phenolic hydrogen and the azomethine N atom. In the crystal, the carbonyl O atom forms bifurcated hydrogen bonds with the two NH atoms of the hydrazinic group, leading to the formation of chains propagating along [001]. Within the chains there are also C-H⋯O hydrogen bonds present. The chains are linked via C=O⋯π [3.4316 (18) Å] and parallel slipped π-π inter-actions, involving inversion-related benzene rings [centroid-centroid distance = 3.8850 (14) Å; inter-planar distance = 3.3895 (10) Å; slippage = 1.899 Å], forming sheets lying parallel to (100).