Synthesis of pyrimidine Schiff base transition metal complexes: characterization,spectral and electrochemical analyses,and photoluminescence properties

Research on Chemical Intermediates - This study includes the synthesis, characterization, electrochemical analysis and photoluminescence properties of a Schiff base ligand bearing a pyrimidine ring...     

Conjugated Polymer Nanoparticle–Graphene Oxide Charge‐Transfer Complexes

The game‐changing role of graphene oxide (GO) in tuning the excitonic behavior of conjugated polymer nanoparticles is described for the first time. This is demonstrated by using poly(3‐hexylthiophene) (P3HT) as a benchmark conjugated polymer and employing an in situ reprecipitation approach resulting in P3HT nanoparticles (P3HT_NPs) with sizes of 50–100 nm in intimate contact with GO. During the self‐assembly process, GO changes the crystalline packing of P3HT chains in the forming P3HT_NPs from H to H/J aggregates exhibiting exciton coupling constants as low as 2 meV, indicating favorable charge separation along the P3HT chains. Concomitantly, π–π interface interactions between the P3HT_NPs and GO sheets are established resulting in the creation of P3HT_NPs–GO charge‐transfer complexes whose energy bandgaps are lowered by up to 0.5 eV. Moreover, their optoelectronic properties, preestablished in the liquid phase, are retained when processed into thin films from the stable aqueous dispersions, thus eliminating the critical dependency on external processing parameters. These results can be transferred to other types of conjugated polymers. Combined with the possibility of employing water based “green” processing technologies, charge‐transfer complexes of conjugated polymer nanoparticles and GO open new pathways for the fabrication of improved optoelectronic thin film devices.     

Breakdown of the resistor-network model for steady-state hopping conduction

Master equations are used to study steady-state hopping in a disordered solid. We express each site's occupancy in terms of its quasi-electrochemical potential (QECP); currents flow between sites whose QECP's differ. Coupled nonlinear circuit equations result from the steady-state condition and a boundary condition. When site-to-site QECP differences are much smaller than the thermal energyk _B T, the effect of current flow on occupancies is ignorable, and the equations reduce to those of a resistance network. But this resistor-network model fails: a) at low temperatures, b) with increasing disorder, and c) with increasing emf. We therefore study hopping conduction beyond this approximation. Exactly soluble examples show the importance of current-induced charge redistribution in non-ohmic steady-state flow.     

Reactions of cyclic oxalyl compounds,part 29: A simple synthesis of functionalized 1H-pyrimidines

Summary 4-Benzoyl-5-phenylfuran-2,3-dione (1) and the semicarbazones2, ureas and thioureas6, respectively, combine with loss of water and carbondioxide yielding the 1H-pyrimidine derivatives3 and7, respectively, in moderate yields (30–75%). Hydrolysis of3 b leads to the 1-amino-pyrimidine-2-one4.Cordially dedicated to o. Univ.-Prof. Dr. Hans Junek on the occasion of his 60th birthday     

Synthesis and Characterization of a New (E,E)-Dioxime and its Homonuclear Complexes

N′-(4′-Benzo[15-crown-5]naphthylaminoglyoxime (H₂L) and its sodium chloride complex (H₂L·NaCl) have been prepared from 2-naphthylchloroglyoxime, 4′-aminobenzo[15-crown-5] and sodium bicarbonate or sodium bicarbonate and sodium chloride. Nickel(II), cobalt(II) and copper(II) complexes of H₂L and H₂L·NaCl have a metal–ligand ratio of 1:2 and the ligand coordinates through the two N atoms, as do most of the vic-dioximes. The BF₂⁺-capped Ni(II), Co(III) and mononuclear complexes of thevic-dioxime were prepared. The macrocyclic ligands and their transition metal complexes have been characterized on the basis of IR, ¹H NMR spectroscopy and elemental analyses data.     

Investigation of therapeutic efficiency of phenytoin (PHT) labeled with radioactive 131I in the cancer cell lines

The aim of this study is to determine the incorporations of PHT radiolabeled with ¹³¹I (¹³¹I-PHT) on U-87 MG, Daoy and A549 cancerous cell lines. For this, cold and radio-labeling studies were carried out. The radio-labeling yield of ¹³¹I-PHT was obtained about 95 %. Subsequently, cell culture studies were carried out and radio-labeling yields of ¹³¹I, ¹³¹I-PHT on U-87 MG, Daoy and A549 cancerous cells were investigated. Cell culture studies demonstrated that the incorporation values of ¹³¹I-PHT on the three cell lines decreased with increasing radioactivity. Consequently, ¹³¹I-PHT may be a good radiopharmaceutical for targeting radionuclide therapy of Central Nervous System Tumors.     

The heating–cooling rate effect on thermal properties of high nickel-rich NiTi shape memory alloy

Journal of Thermal Analysis and Calorimetry - In this study, the effects of heating and cooling rate on the thermal properties of high nickel-rich Ni55Ti45 shape memory alloy were investigated....     

Experimental and Semi-Empirical and DFT Calculational Studies on (<Emphasis Type="Italic">E</Emphasis>)-2-[(2,4-Dichlorophenylimino) methyl]-<Emphasis Type="Italic">p</Emphasis>-cresol

Abstract  

The molecular and crystal structure of the title compound, C₁₄H₁₁Cl₂NO, has been determined by X-ray single crystal diffraction technique. The compound crystallizes in the orthorhombic, space group Pbca with unit cell dimensions a = 7.5537(10) ?, b = 11.5518(13) ?, c = 29.760(4) ?, M _r  = 280.14, V = 2596.8(6) ?³, Z = 8, R ₁ = 0.065 and wR ₂ = 0.191. The title compound exists in the enol–imine tautomeric form with a strong intramolecular O–H···N hydrogen bond. The dihedral angle between the two benzene rings is 37.66(15)°. The asymmetric unit in the crystal structure contains only one neutral molecule. Calculational studies were performed by using AM1, PM3, PM6 semi-empirical and DFT methods. Geometry optimizations of compound have been carried out by using three semi-empirical methods and DFT method and bond lengths, bond and torsion angles of title compound have been determined. Dipole moments (Debye) and the energy parameters of compound (kcal/mol) were calculated by using above mentioned calculation methods. Atomic charge distribution has been obtained from AM1, PM3, PM6 and DFT. In order to determine conformational flexibility on the molecule, molecular energy profile of the title compound was obtained with respect to the selected torsion angle T(N1–C7–C1–C2), which is varied from −180° to +180° in every 10 via PM3 semi-empirical method.