The ONN-complexes of dioxomolybdenum(VI) with dibasic 2-hydroxy-1-naphthaldehyde<Emphasis Type="Italic"> S</Emphasis>-methyl/allyl-4-phenyl-thiosemicarbazones

New dioxomolybdenum(VI) complexes were prepared by reacting S-methyl/allyl-4-phenyl-thiosemicarbazones of 2-hydroxy-1-naphthaldehyde (L ¹ H₂ and L ² H₂) and [MoO₂(acac)₂] in methyl, ethyl and propylalcohols. In the complexes the doubly deprotonated ligands are coordinated to molybdenum as tridentate ONN-donors through phenolic-oxygen, azomethine- and thioamide-nitrogen. The solid complexes of general formula [MoO₂L(ROH)] which contain an alcohol (ROH) as second ligand were characterized by physico-chemical and spectroscopic methods. The fluorescence emission intensities of the compounds were recorded in chloroform, and the intensity changes were evaluated depending on chelation and time. The structure of the S-allyl-4-phenyl-thiosemicarbazone complex has been determined by the single crystal X-ray diffraction method. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and characterization of a new fluorene ligand and its complexes with cobalt(II), copper(II), and ruthenium(II)

A new fluorene ligand, benzo[15-crown-5]-5H-pyrido[3′,2′:4,5]cylopenta[1,2-b]pyridin-5-ylidenehydrazone (bph), has been synthesized from the reaction of 4,5-diazafluoren-9-one with 4′-formylbenzo-15-crown-5. The Co(II), Cu(II), and Ru(II) complexes of the ligand were prepared and characterized. The metal-to-ligand ratio of the Co(II) and Cu(II) complexes was found to be 2:1 and that of the Ru(II) complex was found to be 1:1. The ligand and complexes have been characterized by FTIR, UV–visible, ¹H NMR and fluorescence spectra, as well as elemental analyses and mass spectra.     

Comparing the effect of sub-critical water extraction with conventional extraction methods on the chemical composition of Lavandula stoechas

The volatile extract composition of Lavandula stoechas flowers obtained by hydrodistillation (HD), subcrtical water extraction (SbCWE) and organic solvent extraction under ultrasonic irradiation (USE) were estimated by gas chromatography-mass spectrometry (GC-MS). One hundred and twenty four components were detected in SbCWE extracts while 94 and 65 signals were gained from HD and USE extracts, respectively. Most of the constituents were identified. The major compounds in all three extracts were fenchon, camphor, myrtenyl acetate, myrtenol and 1,8-cineol, but they differ in quantitatively. The total monoterpene hydrocarbons are higher in HD and USE extracts than those of SbCWE extract. However, SbCWE extract had higher concentration of light oxygenated compounds which contributes to the fragrance of the oil in a major extension. Heavy-oxygenated compounds was also in higher abundance in SbCWE extract (9.90%) than those of HD and USE extracts (3.19 and 4.78%, respectively). Effect of temperature on the extraction yield of SbCWE was investigated and while oil yield was increasing with an increase in temperature, a decrease in the extraction ability of sub-critical water toward the more polar compounds such as, 1,8-cineol, camphor and fenchon, was observed. Kinetic studies shown that SbCWE is clearly quicker than conventional alternatives. Most of components of volatile compounds were extracted at 15min.     

Schiff base substitute polyphenol and its metal complexes derived from o‐vanillin with 2,3‐diaminopyridine: synthesis,characterization, thermal,and conductivity properties

Poly‐2,3‐bis[(2‐hydroxy‐3‐methoxyphenyl)methylene]diamino pyridine (PHMPMDAP) that a new Schiff base polymer has been synthesized and characterized by spectroscopy, elemental, and thermal analyses techniques. This azomethine polymer was found to form complexes readily with Cu(II), Zn(II), Co(II), Pb(II), and Fe(II). From IR and UV‐Vis studies, the phenolic oxygen and imine nitrogen of the ligand were found to be the coordination sites. Thermogravimetric analysis (TGA) data indicate the polymer to be more stable than the monomer. The structure of the polymer obtained was confirmed by FT‐IR, UV‐Vis, ¹³C‐NMR, and ¹H‐NMR. Characterization was undertaken by TGA, size exclusion chromatography (SEC), and solubility tests. Also, electrical conductivities of PHMPMDAP and polymer–metal complexes are measured by four probe technique. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis and characteristics of <Emphasis Type="Italic">N</Emphasis>-(glyoxyldioxime)-<Emphasis Type="Italic">N</Emphasis>′-(2-hydroxybenzylidene)-1,4-diaminonaphthalene and its metal complexes

A new vic-dioxime, N-(glyoxyldioxime)-N′-(2-hydroxybenzylidene)-1,4-diaminonaphthalene, was synthesized proceeding from naphthalene. Its complexes of nickel, copper and cobalt were prepared. The vicdioxime and its complexes were charecterized by FT-IR, UV, ¹H NMR, mass spectrometry, elemental analysis, DTA/TG analysis techniques and conductometric measurements. Published in Russian in Zhurnal Obshchei Khimii, 2008, Vol. 78, No. 5, pp. 797–802. The text was submitted by authors in English.     

Chitosan based hybrid hydrogels for drug delivery: Preparation,biodegradation, thermal,and mechanical properties

In the present paper, biodegradable hybrid hydrogels were prepared by using chitosan as a natural polymer and polyurethane containing azomethine as a synthetic polymer for the drug delivery application for 5-fluorouracil. The fabricated hydrogels were characterized via FT-IR and SEM analysis. Besides, the thermal, mechanical, and wettability properties, water uptake, biodegradation, protein absorption, drug loading, and release behaviors of the hybrid hydrogels were studied. The obtained results indicated that the fabricated hybrid hydrogels have exhibited good mechanical, hydrophilic, water uptake, and biodegradation behaviors. The hybrid hydrogels also showed 50% drug release amounts and they could be a good candidate for the controlled delivery of 5-FU due to these properties.     

Experimental and Theoretical Spectral(FT-IR,Raman,NMR,UV-Vis and NLO)Analysis of a Potential Anti-Tumor Drug:1-Methyl-6-Nitro-1H-Benzimidazole

In the present work, the experimental and the theoretical spectroscopic properties of 1-Methyl-6-Nitro-1H- Benzimidazole were investigated. The FT-IR (400~4 000 cm-1) and FT-Raman spectra (100~4 000 cm-1) of 1-Methyl-6-Nitro-1H- Benzimidazole in the solid phase were recorded. Also, experimental NMR and UV spectra of titled molecule were measured. To interpret the experimental data, geometric parameters, vibrational frequencies, NMR, UV spectra and NLO analysis of the optimized molecule were calculated using ab initio Hartree–Fock (HF) method and density functional theory (B3LYP) method with the 6-31++G(d,p) and 6-311++G(d,p) basis sets. Vibrational bands were assigned based on the potential energy distribution using the VEDA 4 program. The theoretical results showed good agreement with the experimental values.     

Genetic programming modelling for the electrical resistivity of Cu–Zn thin films

Using quantum hydrodynamic (QHD) model and standard reductive perturbation method, we have investigated the formation and characteristics of space-charge solitary waves and double layers in n-type compensated drifting semiconductor plasma with varying doping profiles. Through numerical analysis, it is shown that the structures of space-charge solitary waves and double layers depend significantly on electron drift and compensation parameter which measures a comparative proportion of the donor, acceptor and intrinsic ion concentrations.     

The electromagnetic energy with the truncation method for a five-dimensional rotating black hole in a uniform magnetic field

We consider a charged five-dimensional Myers–Perry black hole in a uniform magnetic (test) field. Using the Komar mass formula, we calculate the total energy of the electromagnetic field within the truncation three-sphere for a five-dimensional rotating black hole with two equal-rotation parameters and two equal-magnetic field strengths. We show that the total electromagnetic energy takes the minimum value when the five-dimensional rotating black hole acquires a non-zero net electric charge Q.     

High diastereoselectivity induced by intermolecular hydrogen bonding in [3 + 2] cycloaddition reaction: experimental and computational mechanistic approaches

A diastereoselective [3 + 2] cycloaddition of N‐aryl substituted maleimides with N,α‐diphenyl nitrone possessing 11‐hydroxyundecyloxy as a flexible substituent was performed. Experimental and comprehensive mechanistic density functional theory studies reveals that intermolecular H‐bonding and steric repulsive interaction predominate exo‐Z and exo‐E cycloaddition transition states, respectively. The reaction proceeded smoothly depending on the reactants and gave a good yield of (syn) cis‐isoxazolidine or (anti) trans‐isoxazolidine as a single diastereomer.