Hakan Arslan

Bio: Hakan Arslan is an academic researcher from Mersin University. The author has contributed to research in topics: Crystal structure & Chemistry. The author has an hindex of 25, co-authored 127 publications receiving 2019 citations. Previous affiliations of Hakan Arslan include Georgia Institute of Technology & Emory University.

Antimicrobial Activity of Some Thiourea Derivatives and Their Nickel and Copper Complexes

Abstract: Five thiourea derivative ligands and their Ni 2+ and Cu 2+ complexes have been synthesized. The compounds were screened for their in vitro anti-bacterial activity using Gram-positive bacteria (two different standard strains of Staphylococcus aureus , Staphylococcus epidermidis , Enterococcus faecalis , Streptococcus pyogenes , Bacillus cereus ) and Gram-negative bacteria ( Esherichia coli , Pseudomonas aeruginosa , Enterobacter cloacae , Proteus vulgaris , Enterobacter aerogenes ) and in vitro anti-yeast activity ( Candida albicans , Candida krusei , Candida glabrata , Candida tropicalis , Candida parapsilosis ). The minimum inhibitory concentration was determined for all ligands and their complexes. In vitro anti-yeast activity of both ligands and their metal complexes is greater than their in vitro anti-bacterial activity. The effect of the structure of the investigated compounds on the antimicrobial activity is discussed. Keywords: Thiourea derivatives; Complexes; Antibacterial activity; Antifungal activity;

Synthesis and characterization of copper(II), nickel(II) and cobalt(II) complexes with novel thiourea derivatives

Abstract: A novel series of thiourea derivatives, namely, N,N-diphenyl-N′-(4-phenyl-benzoyl)thiourea (HL1), N,N-diphenyl-N′-(4-chloro-benzoyl)thiourea (HL2) and N,N-di-n-propyl-N′-(4-chloro-benzoyl)thiourea (HL3), and its metal complexes has been prepared and characterised by elemental analysis, i.r. spectroscopy, 1H-n.m.r. spectroscopy, mass spectrometry and single crystal X-ray diffraction. The ligand coordinates to NiII, CuII and CoII in a bidentate manner yielding essentially neutral complexes of the type cis-[ML2]. N.m.r. spectra and single crystal X-ray diffraction analysis revealed the presence of a distorted tetrahedral coordination ML2 complex.

Heavy metals in street dust in bursa, turkey

Abstract: The trace element contents of street dust samples collected from streets in the Bursa City, Turkey, have been determined by flame-atomic absorption spectrometry after digestion with aqua regia. The mean concentration levels of Pb, Ni, Cd, Zn and Mn were found to be 210, 67, 3.1, 57 and 500 μg/g, respectively. A good correlation between the number of cars or total number of vehicles and the metal contents is found.

Theoretical and experimental studies on N-(6-methylpyridin-2-yl-carbamothioyl)biphenyl-4-carboxamide

Abstract: A novel thiourea derivative, N -(6-methylpyridin-2-yl-carbamothioyl)biphenyl-4-carbox amide, is synthesized and characterized by elemental analysis, FT-IR, NMR and single crystal X-ray diffraction study. There are two independent molecules A and B in the asymmetric unit. The short bond lengths of the C-N bonds in the central thiourea fragment indicate partial double bond character in this fragment of the title compound. These results can be explained by the existence of resonance in this part of the molecule. Each A and B molecule is stabilized with an intramolecular N-H•••O hydrogen bond which results in the formation of a pseudo six membered ring. In addition, the independent molecules are linked into a chain along the c axis by weak N-H•••S intermolecular hydrogen bonds. The conformational behavior and structural stability of the optimized geometry of the title compound were also investigated by utilizing ab- initio calculations with 6-31G* basis set at HF, BLYP, and B3LYP levels. The calculated parameters are in good agreement with the corresponding X-ray diffraction values.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Hydrogen Bonding in the Electronic Excited State

Abstract: Because of its fundamental importance in many branches of science, hydrogen bonding is a subject of intense contemporary research interest. The physical and chemical properties of hydrogen bonds in the ground state have been widely studied both experimentally and theoretically by chemists, physicists, and biologists. However, hydrogen bonding in the electronic excited state, which plays an important role in many photophysical processes and photochemical reactions, has scarcely been investigated.Upon electronic excitation of hydrogen-bonded systems by light, the hydrogen donor and acceptor molecules must reorganize in the electronic excited state because of the significant charge distribution difference between the different electronic states. The electronic excited-state hydrogen-bonding dynamics, which are predominantly determined by the vibrational motions of the hydrogen donor and acceptor groups, generally occur on ultrafast time scales of hundreds of femtoseconds. As a result, state-of-the-art femtos...