Amel Djedouani

Bis[3‐acetyl‐6‐methyl‐2H‐pyran‐2,4(3H)‐dionato]bis­(dimethyl sulfoxide)copper(II)

Laboratoire d0Electrochimie des Matériaux Moléculaires et Complexes, Département de Génie des Procédés, Faculté des Science de l0Ingénieur, Université Farhat Abbes de Setif, DZ-19000 Sétif, Algeria, Département de Chimie, Faculté des Sciences et Sciences de l0Ingénieur, Université A. Mira de Béjaia, Route Targua Ouzmour 06000 Béjaia, Algeria, and Laboratoire de Chimie Moléculaire, du Contrôle de l0Environnement et de Mesures Physico-Chimiques, Département de Chimie, Faculté des Sciences, Université Mentouri 25000, Constantine, Algeria

Zwitterionic 6-methyl-2-oxo-3-[1-(ureido­iminio)eth­yl]-2H-pyran-4-olate monohydrate

The title compound, C9H11N3O4·H2O, was prepared by the reaction of dehydroacetic acid and semicarbazide hydrochloride. It crystallizes in a zwitterionic form with cationic iminium and anionic enolate groups. In the crystal structure, the almost planar molecules are held together by N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds, some of them involving the water molecules.

4-Hy-droxy-6-methyl-3-[3-(thio-phen-2-yl)acrylo-yl]-2H-pyran-2-one.

The title compound, C13H10O4S, crystallizes with two molecules in the asymmetric unit in which the rings make dihedral angles of 3.9 (1) and 6.0 (1)°; this planarity is due in part to the presence of an intramolecular O—H⋯O hydrogen bond, which generates an S(6) ring in each molecule. Both molecules represent E isomers with respect to the central C=C bond. In the crystal, molecules are linked by C—H⋯O interactions into a three-dimensional network.

Liquid-liquid extraction of metal ions, DFT and TD-DFT analysis for some pyrane derivatives with high selectivity for Fe(II) and Pb(II)

ABSTRACT Liquid-liquid extraction of metal ions using pyrane derivatives was studied. Fe2+, Zn2+, Cu2+, Co2+, Cd2+, Ni2+, and Pb2+ were extracted from the aqueous phase into the organic phase and the extractability for each metal was determined by atomic absorption. Interestingly, a competitive extraction was also investigated and then examined at different pH in order to explore the effect of the different substituent groups on metal extraction. We found high selectivity towards Fe2+ (91.8%) and Pb2+ (90.7%). In addition, geometry optimizations of the ground and excited-states of the selective ligands in order to get better insight into the geometry and the electronic structure were carried out by DFT and TD-DFT calculations.

Bis(3-acetyl-6-methyl-2-oxo-2H-pyran-4-olato)bis-(dimethyl sulfoxide)nickel(II).

In the title compound, [Ni(C8H7O4)2{(CH3)2SO}2], the NiII atom is located on a crystallographic centre of symmetry and has a distorted octahedral coordination geometry of type MO6. The bidentate dehydroacetic acid (DHA) ligands occupy the equatorial plane of the complex in a trans configuration, and the dimethyl sulfoxide (DMSO) ligands are weakly coordinated through their O atoms in the axial positions.

Crystal structure and DFT study of the zwitterionic form of 3-{(E)-1-[(4-ethoxyphenyl)iminiumyl]ethyl}-6-methyl-2-oxo-2H-pyran-4-olate

The title Schiff base compound crystallizes in the zwitterionic form. The resulting iminium and hydroxyl groups are linked by a charge-assisted intramolecular N+—H⋯O− hydrogen bond, and the conformation about the C=N bond is E.

Crystal structure of (E)-1-[4-({4-[(4-meth-oxy-benzyl-idene)amino]-phen-yl}sulfan-yl)phen-yl]ethan-1-one.

The title Schiff base compound, C22H19NO2S, crystallized with two independent molecules (A and B) in the asymmetric unit. Both molecules have an E conformation about the C=N bond. The two molecules differ in the orientation of the aromatic rings with respect to each other. The outer 4-methoxybenzene ring is inclined to the central benzene ring and the outer 4-acetylbenzene ring by 1.80 (19) and 63.73 (19)°, respectively, in molecule A, and by 6.72 (18) and 68.53 (19)°, respectively, in molecule B. The two outer benzene rings are inclined to one another by 63.77 (18) and 63.19 (18)° in molecules A and B, respectively. In the crystal, the individual molecules stack in columns along [010], and are linked by a number of C—H⋯π interactions, forming slabs lying parallel to (001).

Crystal structure of (E)-4-hy-droxy-3-{1-[(4-hy-droxy-phen-yl)imino]-eth-yl}-6-methyl-2H-pyran-2-one.

In the title Schiff base, C14H13NO4, which adopts the phenol–imine tautomeric form, the dihedral angle between the planes of the benzene and heterocyclic (r.m.s. deviation = 0.037 Å) rings is 53.31 (11)°. An intramolecular O—H⋯N hydrogen bond closes an S(6) ring. In the crystal, molecules are linked by O—H⋯O hydrogen bonds to generate C(11) chains propagating in the [010] direction. A weak C—H⋯O link is also observed, leading to the formation of R 5 5(32) rings extending parallel to the (101) plane.