Adnan Cetin

Synthesis and characterization of conjugated polymers containing phenyl and bithiophene: controlling of optical properties with molarity

Conjugated polymers containing phenyl and bithiophene units are synthesized by conventional polycondensation and crossing-coupling method of carboxylic acids with halides. The structure of both polymers formed by adding the ester group to the first polymer was confirmed by means of Fourier transform infrared (FTIR), nuclear magnetic resonance techniques, differential scanning calorimetry, and thermogravimetry and elemental analysis. The molecular weight distribution values of polymers were determined with a gel permeation chromatography (GPC) system. The optical properties of these different polymers with synthesis methods and structures were investigated for different molarities. The molar extinction coefficient values of the polymers decrease with increasing molarity. Transmittance (T) values of the polymers are increased with ester group addition and decreasing molarity. We obtained two types (direct and indirect allowed band gaps) of band gaps. The direct allowed optical band gap (Egd) values of poly(2,2′ bithiophene terephthalate) (polyBTTP) are lower than the indirect allowed optical band gap (Egid) values of poly(5-phenyl-2,2′ bithiophene) (polyPBT). The direct and indirect allowed band gap values of the polymers can be decreased with ester group addition and increasing molarity. The refractive index of the polymers can be decreased with decreasing molarity, increasing wavelength, and ester group addition.

Unsymmetrical pyrazole-based new semiconductor oligomer: synthesis and optical properties

Poly(p-phenylene-1-(2,5-dimethylphenyl)-5-phenyl-1H-pyrazole-3,4-dicarboxy amide) (poly(PDPPD)) was synthesized from reactions of p-phenylene-diamine and 1-(2,5-dimethylphenyl)-5-phenyl-1H-pyrazole-3,4-dicarbonyl dichloride (monomer) by heating under solvent. This newly synthesized poly(PDPPD) was characterized by 1H, 13C-NMR, FT-IR, gel permeation chromatography (GPC). In addition, we investigated optical properties of the poly(PDPPD) containing the substituted pyrazole ring at different molarities. The average transmittance (Tavg) values of the poly(PDPPD) in the visible (V) region were higher than the Tavg values in the near-ultraviolet (NU) region. The Tavg values of the poly(PDPPD) in the NU and visible (V) region decreased with increasing molarity. The absorption band edge (Absbe) value of the poly(PDPPD) decreased with increasing molarity. It was observed that the optical band gap (Eg) of the poly(PDPPD) value decreased more with increasing molarity. The refractive index of the poly(PDPPD) decreased with increasing wavelength and decreasing molarity. The structure of the poly(PDPPD) in the lowest energy was optimized by DFT calculation and its HOMO–LUMO orbitals were plotted.

Some pyrazoles derivatives: Potent carbonic anhydrase, α-glycosidase, and cholinesterase enzymes inhibitors

A series of substituteed pyrazol‐4‐yl‐diazene derivatives were found to be effective inhibitors against α‐glycosidase, cytosolic carbonic anhydrase I and II isoforms (hCA I and II), butyrylcholinesterase (BChE), and acetylcholinesterase (AChE) with Ki values in the range of 33.72 ± 7.93 to 90.56 ± 27.52 nM for α‐glycosidase, 1.06 ± 0.16 to 9.83 ± 0.74 nM for hCA I, 0.68 ± 0.12 to 7.16 ± 1.14 nM for hCA II, 44.66 ± 10.06 to 78.34 ± 17.83 nM for AChE, and 50.36 ± 13.88 to 88.36 ± 20.03 nM for BChE, respectively. Recently, inhibition of these metabolic enzymes has been considered as a promising factor for pharmacologic intervention in a diversity of disturbances, such as diabetes, glaucoma, obesity, epilepsy, cancer, and neurodegenerative diseases.

Synthesis of Pyrazoles via Electrophilic Cyclization of Alkynes Containing Thiophene

Background: Pyrazole is a simple aromatic ring an organic compound of the heterocyclic series that characterized five-membered ring structure which comprises located adjacent two nitrogen atoms and three carbon atoms. In recent years interest in the pyrazole chemistry excessively has increased due to many a wide range of properties. Because they have a wide range of specific properties such as biological activities, pharmaceutical i.e., Pyrazoles were also applied successfully in many fields; medicine, agricultural, industry, pharmaceutical chemistry so that pyrazole chemistry was quite an interesting area of research for the synthesis of their derivatives and investigates new methods. Methods: Research and online content related to synthesis pyrazole and electrophilic cyclization of molecules are reviewed. Excerpts are used to illustrate key themes about chemistry of organic substances bearing pyrazole group. All the solvents and chemical materials were purchased. All the reagents were used directly without purification. Results: The new substitute α,β-alkynic hydrazones was prepared by heating directly from thiophene-2-acetyl chloride and terminal alkyne via a palladium-catalyzed coupling reaction then a series of the new substituted pyrazole derivatives were converted via electrophilic cyclization by catalyst and characterizations of each compound were indicated by the help of spectral data. Conclusion: The new different substitute pyrazoles were synthesized via copper mediated electrophilic cyclization. Firstly, the various hydrazones derivatives were carried out by the condensation reactions of the propargyl ketone that prepared from phenyl acetylene and acyl chloride with hydrazines. The various pyrazoles contain that thiophene were obtained by electrophilic cyclization copper(I) iodide and the various hydrazones. In addition, synthesized of substitute pyrazoles may be apply the other fields because of their diverse and potent biological properties. For this reason, the syntheses of different pyrazole compounds are becoming more importance.