Investigation of temperature dependent electrical and impedance characteristics of bulk Zn0.95Co0.05O

Journal of Sol-Gel Science and Technology - Zn0.95Co0.05O was synthesized by sol-gel method and then Zn0.95Co0.05O pellet was prepared to investigate its structural, morphological, electrical, and...     

Novel N‐Alkylbenzimidazole‐Ruthenium (II) complexes: Synthesis and catalytic activity of N‐alkylating reaction under solvent‐free medium

In this article, direct N‐alkylation reactions of amines with alcohols derivatives have been investigated. For this purpose, a new series ruthenium (II) complexes bearing N‐coordinated benzimidazole complexes with have been synthesized and fully characterized by elemental analysis, FT‐IR, ¹H NMR and, ¹³C NMR spectroscopies. Additionally, the structures of the complexes 2b and 2c have been confirmed by X‐ray crystallography. Although the N‐alkylating reaction is usually performed in toluene, the catalytic study of complexes 2a‐d has carried out no additional solvent and alcohol acted both as solvent and reactant of alkylating by using a little excess of alcohols. Surprisingly, conversion and selectivity of amine product for alkylation reaction have been seen high in medium solvent‐free relative to in toluene.     

Synthesis,spectral, X-ray diffraction and DFT studies on 1-(2-methyl-2-propenyl)-3-(2,3,4,5,6-pentamethylbenzyl)benzimidazolium chloride hydrate

A new benzimidazole based N-heterocyclic carbene (NHC) salt (1) was synthesized by the reaction of benzimidazole precursor with alkyl halide. The structure of 1 was determined by elemental analysis, FT-IR, ¹H NMR and ¹³C NMR spectroscopy tecniques and X-ray crystallography. The compound crystallized in the triclinic space group P-1 with two molecules in the unit cell. The optimization of 1 was firstly performed at B3LYP/6-311G++(d,p) level, then the theoretical spectral studies performed and compared with the experimental values. Besides the frontier molecular orbital energies and chemical reactivity analysis of 1, together with the electrostatic potential and molecular electrostatic potential analyses were performed at the same level of theory.     

New 3-vinylation products of indole and investigation of its Diels-Alder reactivity: synthesis of unusual Morita-Baylis-Hillman-type products

3-Vinylindoles as precursors of carbazole and bis-indole derivatives were synthesized. Then, to form new carbazoles, Diels-Alder reactivity of these vinylindoles was studied with various dienophiles. During the cycloaddition reaction, unusual Morita-Baylis-Hillman-type products were observed. The structure and the formation mechanism of the products is discussed.     

Stereospecific synthesis of highly substituted novel carbasugar as carbonic anhydrase inhibitors: decahydronaphthalene-1,2,3,4,5,6,7-heptol

Decahydronaphthalene-1,2,3,4,5,6,7-heptol, a new polycyclitol, was synthesized starting from p-benzoquinone. An endo selective Diels-Alder cycloaddition between p-benzoquinone and 1-acetoxybutadiene followed by stereoselective reduction with NaBH₄/CeCl₃·7H₂O led to the formation of an allylic cis-diol. The formed diol was converted into its acetate with Ac₂O/pyridine, in a transformation that required inert atmosphere conditions to suppress a competing aromatization. Controlled oxidation by OsO₄ of two olefinic bonds followed by acetylation yielded the heptaacetate whose structure was established unequivocally via application of X-ray crystallographic methods. Removal of the acetate groups by NH₃ provided the target heptol. In addition, the carbonic anhydrase inhibitory potency of the title compound was investigated and it was shown to be a potent inhibitor compared to the standard CA inhibitors.     

Synthesis of Novel Thioethers and Sulfoxide Compounds

Abstract

Thiosubstituted butadiene and butenyne compounds were synthesized from the reactions of 1,1,3,3,4,4-hexachloro-1-butene or 1,1,2,4,4-pentachlorobuta-1,3-diene with different thiols in EtOH/H₂O solution of NaOH. Tris(thio)substituted butadiene compound was treated with potassium tert-butoxide to obtain tris(thio)substituted butatrienyl halide compound. The novel sulfoxide compounds were synthesized from the reactions of polyhalobutadiene compounds with aliphatic thiols in CHCl₃ with m-CPBA at 0°C. The structures of the novel compounds were characterized by micro analysis, FT-IR, ¹H-NMR, ¹³C-NMR, and MS.     

Asymptotics of eigenvalues for regular Sturm-Liouville problems with eigenvalue parameter in the boundary condition

In this paper we obtain asymptotic estimates of eigenvalues for regular Sturm-Liouville problems having the eigenparameter in the boundary condition. The method is based on an iterative procedure solving the associated Riccati equation and producing an asymptotic expansion of the solution in the higher powers of 1/λ1/2 as λ→∞.