Mehmet Aslantaş

Chemical fixation of CO2 into cyclic carbonates by azo-containing Schiff base metal complexes

Two new ligands containing a –NN– group, 4-((E)-(4-bromophenyl)diazenyl)-2-((E)-(phenylimino)methyl)phenol (L1H, 2), 4-((E)-(4-bromophenyl)diazenyl)-2-((E)-((4-ethylphenyl)imino)methyl)phenol (L2H, 3) and their metal complexes were synthesized. The synthesized metal complexes were used as catalysts for the chemical fixation of CO2 into cyclic carbonates using epoxides which were used as both substrate and solvent. According to analytical, UV-visible and IR data, the metal complexes are formed by coordination of the N and O atoms of the ligands and the metal : ligand ratio was found to be 1 : 2 for all the complexes. The TG and DTA results showed that these complexes had good thermal stability. The molecular structures of ligand 2 (L1H) and its ZnII complex 4 (Zn(L1)2) were determined by single crystal X-ray diffraction studies. After choosing the most active catalyst (Zn(L1)2, 4), optimization studies were performed by changing various parameters. Ionic liquids have been found to have a positive effect and showed the most active performance with (bmim)PF6 + Zn(L1)2 (4) as a binary catalytic system.

The NIGMS structural biology facility at the NSLS

With the advent of structural genomics and the post-genomic era, there is an increased demand for synchrotron radiation facilities for macromolecular structural biology [1]. Several of the existing facilities are affiliated in one or more ways with the newly created Centers for Structural Genomics, leaving individual investigators with little to no access to synchrotron radiation. To provide synchrotron access for these small groups, the National Institute of General Medical Sciences (NIGMS) established the X6A facility at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The purpose is to provide synchrotron access to individual macromolecular crystallography groups and to the biological/biochemical and biophysical community at large. It is the X6A mission to assist expert and nonexpert crystallographers and provide training to interested individuals in the areas from protein purification to the determination of the molecular atomic coordinates.

Spectroscopic, thermal and voltammetric studies of crystalline complex trans-N,N′-bis(salicylidene)-1′,2′-cyclohexanediamine with Cu(II)

The dimeric complex, [C20H20CuN2O2]2, has been prepared and characterized by thermal analysis, IR spectroscopy and single-crystal X-ray diffraction techniques. The Cu atom in the binuclear complex exists in a distorted square-pyramidal configuration, defined by three O atoms and two N atoms. The crystal structure is stabilized by intermolecular C-H...O hydrogen bonding interaction. The electrochemical property of the complex was investigated in CH2Cl2 by cyclic voltammetry at 100 mV s(-1) scan rate.

Correction: Chemical fixation of CO2 into cyclic carbonates by azo-containing Schiff base metal complexes

Correction for ‘Chemical fixation of CO2 into cyclic carbonates by azo-containing Schiff base metal complexes’ by Mesut Ikiz et al., New J. Chem., 2015, DOI: 10.1039/c5nj00571j.

Crystal structure of rac-3-hy­droxy-2-(p-tol­yl)-2,3,3a,4,7,7a-hexa­hydro-1H-4,7-methano­isoindol-1-one

In the title compound, C16H17NO2, the cyclohexene ring adopts a boat conformation, and the five-membered rings have envelope conformations with the bridging atom as the flap. Their mean planes are oriented at a dihedral angle of 86.51 (7)°. The molecular structure is stabilized by a short intramolecular C—H⋯O contact. In the crystal, molecules are linked by O—H⋯O hydrogen bonds forming chains propagating along [100]. The chains are linked by C—H⋯π interactions, forming slabs parallel to (001).

Single crystal X-ray structure and optical properties of anthraquinone-based dyes

This study focuses on the preparation, single crystal X-ray diffraction, characterization, and optical properties of some anthraquinone-based dyes. The anthraquinone-based antimicrobial dye N-{2-[(9,10-dioxo-9,10-dihydroanthracen-1-yl)amino]-2-oxoethyl}-N,N-dimethylbutan-1-aminium chloride monohydrate (III) was obtained from 1-aminoanthraquinone (I) via 2-chloro-N-(9,10-dioxo-9,10-dihydroanthracen-1-yl)acetamide (II) using known preparation and characterization methods. Single crystal X-ray diffraction analysis of III revealed a monoclinic system, space group P21/n, Z = 4. Photoluminescence properties of anthraquinone dyes I–III were also investigated. These dyes gave an intense emission (λmax = 341 nm) upon the irradiation by UV light and showed photoluminescence quantum yields of 73 %, 66 %, and 61 % with long excited-state lifetimes of 6.87 ns, 6.14 ns, and 5.69 ns, respectively. These anthraquinone dyes are of interest as an organic light emitting material for electroluminescent devices.