Synthesis of Two Alnustone-Like Natural Diarylheptanoids via 4 + 3 Strategy

The first total synthesis of (4E,6E)-1,7-bis(3,4-dihydroxyphenyl)-hepta-4,6-dien-3-one and an alternative synthesis of (4E,6E)-1,7-bis(4-hydroxyphenyl)-hepta-4,6-dien-3-one, two natural diarylheptanoids, mainly based on Claisen–Schmidt condensation were described. The crucial steps of the syntheses were the condensation of OH-protected 4-aryl-2-butanones with OH-protected 3-aryl-acrylaldehydes by the in situ enamination and then deprotection of OH groups to give the corresponding natural diarylheptanoids.     

Approximate analytical solutions of a two-term diatomic molecular potential with centrifugal barrier

Approximate analytical bound state solutions of the radial Schr?dinger equation are studied for a two-term diatomic molecular potential in terms of the hypergeometric functions for the cases where q?≥?1 and q?=?0. The energy eigenvalues and the corresponding normalized wave functions of the Manning–Rosen potential, the ‘standard’ Hulthén potential and the generalized Morse potential are briefly studied as special cases. It is observed that our analytical results are the same with the ones obtained before.     

Synthesis and spectroscopic studies of mixed-ligand and polymeric dinuclear transition metal complexes with bis-acylhydrazone tetradentate ligands and 1,10-phenanthroline

Two types of dinuclear copper(II) and nickel(II) complexes with two tetradentate N2O2 donor ligands 1,4-bis(1-anthranoylhydrazonoethyl)benzene (L1), 1,4-bis(1-salicyloylhydrazonoethyl)benzene (L2) and N,N'-bidentate heterocyclic base [1,10-phenonthroline (phen)] have been synthesized and characterized by elemental analysis, infrared spectra, UV-vis electronic absorption spectra and magnetic susceptibility measurements. The reaction of metal(II) acetates with the solution containing ligand and 1,10-phenonthroline in methanol gives mixed-ligand dinuclear metal(II) complexes with general formula [M2L(phen)2]Cl2 (L=L1 or L2), whereas, the ligands react with metal(II) acetates to form polymeric dinuclear complexes with general formula [(M2L2)n] (L=L1 or L2). In the complexes, the ligands act as dianionic tetradentate and coordination takes place in the enol tautomeric form with the enolic oxygen and azomethine nitrogen atoms while the phenolic hydroxyl and amino groups of aroylhydrazone moiety do not participate in coordination. The effect of varying pH and solvent on the absorption behavior of both ligands and complexes has been investigated.     

Synthesis and EPR studies of vanadyl tetrakis(selenodiazole)porphyrazine

Tetrakis(selenodiazole)porphyrazine and its vanadyl (VO²⁺) complex have been prepared and characterized by FT-IR, UV–vis, and MALDI-MS. The magnetic properties of the complex have been investigated by EPR spectroscopy.     

Facile conversion of pyridine propargylic alcohols to enones: stereochemistry of protonation of allenol

The conversion of 4-pyridyl propargylic alcohols 1 to the (E)-propenones 3 and propynones 2 occurs under mild reaction conditions, pyridinium chloride in methanol at room temperature. (Z)-4-Pyridyl propenones 11 are detected as initial products when large substituents such as trimethylsilyl, tert-butyl and phenyl are attached at C-3 of the propynols and these (Z)-enones 11 are isomerised to the (E)-isomers 3 under the reaction conditions. In the presence of deuterated solvent, both hydrogens at the double bond of enone 3d are deuterated. An allenol is proposed as intermediate whose preferential protonation occurs at the less hindered side giving the (Z)-enone. The propargylic alcohols, pyridin-2-yl 12 and quinolin-4-yl 5, are converted to (E)-enones 13 and 7, respectively.     

Polyurethane elastomers with hydrolytic and thermooxidative stability. I. Polyurethanes with N-alkylated polyamide soft blocks

Segmented polyurethanes with N-alkylated amides as soft blocks as prepared. Comparisons are made with both a poly(ester urethane) and a poly(ether urethane) with the same hard block; the poly(amide urethane) is more hydrolytically stable than the polyester containing material and demonstrates greater thermooxidative stability than that with the polyether moiety. The aliphatic poly(amide urethane)s remain transparent upon exposure to uv light.     

Relativistic solution in D-dimensions to a spin-zero particle for equal scalar and vector ring-shaped Kratzer potential

The Klein-Gordon equation in D-dimensions for a recently proposed ring-shaped Kratzer potential is solved analytically by means of the conventional Nikiforov-Uvarov method. The exact energy bound states and the corresponding wave functions of the Klein-Gordon are obtained in the presence of the non-central equal scalar and vector potentials. The results obtained in this work are more general and can be reduced to the standard forms in three dimensions given by other works.