Structural and Stereochemical Analysis of Some 9-Phenyl-8-N-substituted Thiocarbamoyl-7,8-Diazabicyclo [4.3.0]non-6-enes by NMR and Mass Spectrometric Techniques

In this study the structural and stereo chemical analysis of some 9-Phenyl-8-N-Substituted thiocarbamoyl-7,8-diazabicyclo[4.-3.0] and the new synthesized 5-Methyl–9-phenyl-8-N-Substituted-thiocarbamoyl-7, 8-diazabicyclo[4.-3.0]non-6-enes derivatives were studied by 2D NMR, 1D NOE experiments and electron impact mass spectrometry were reported. The N-substituted thiocarbamoyl compounds were mixtures of diastereomers as evidenced by differing Rf values on TLC plates. They were separated by successive applications of preparative TLC and structures were elucidated by IR, ¹R-NMR, ¹³C-NMR, DEPT, 2D-NMR and EI-MASS techniques. The is-trans isomerism of the compounds were determined by means of ¹H-NMR, ¹³C-NMR and 1D NOE difference experiments. The conformation analysis of the bicyclic ring system was based on NOE difference experiments and NOESY spectra of compound-11. For the application of 1D NOE experiments, compound 11 was selected.     

Synthesis,characterization, aggregation and thermal properties of a novel polymeric metal-free phthalocyanine and its metal complexes

A novel polymeric metal-free phthalocyanine (M = 2H) and its metal complexes (M = Zn, Cu, Co and Ni) were prepared by the tetramerization reaction of 3,6,9-Tris(p-tolylsulfonyl)-1,11-bis(3,4-dicyanophenoxy)-3,6,9-triazaundecane 5 with the appropriate materials. The electrical conductivities of the metal-free phthalocyanine and the metal complexes, measured in air, were found to be ∼10⁻⁶–10⁻⁵ S m⁻¹. The aggregation property of the zinc complex 7 was investigated with Ni²⁺, Cu²⁺, Co²⁺, Pb²⁺, Cd²⁺ and Ag⁺ cations. Thermal analysis of the polymers were done by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) at a heating rate of 10 °C min⁻¹ under a nitrogen atmosphere. All the novel compounds were characterized by using elemental analysis, UV–Vis, FT–IR, NMR and MS spectral data and DSC, DTA/TG techniques.     

(Liquid + liquid) equilibria of (water + propionic acid + alcohol) ternary systems

(Liquid + liquid) equilibrium (LLE) data of the solubility (binodal) curves and tie-line end composition were examined for mixtures of {water (1) + propionic acid (2) + octanol or nonanol or decanol or dodecanol (3)} at T = 298.15 K and 101.3 ± 0.7 kPa. The reliability of the experimental tie-line data was confirmed by using the Othmer-Tobias correlation. The LLE data of the ternary systems were predicted by UNIFAC method. Distribution coefficients and separation factors were evaluated for the immiscibility region.     

Topical use of liposomal copper palmitate formulation blocks porphyrin-induced photosensitivity in rats

Photodynamic therapy (PDT) is a new treatment modality that uses porphyrin derivatives and visible light, especially for the treatment of cancer. However, PDT with certain photosensitisers can cause prolonged skin photosensitization. This is particularly true for Photofrin II (Photofrin)-mediated PDT where patients are required to avoid direct exposure to sunlight for a period of 4-6 weeks. This is the only long-term adverse reaction to the drug. Recent studies have shown that topical copper treatment avoids this type of inflammatory reaction. In this study, we have tested the efficiency of the liposomal formulation of copper palmitate on porphyrin-photosensitized rats. Initially, adult male Sprague-Dawley rats were rendered photosensitive either by administration of Photofrin or aminolevulinic acid (ALA), a precursor of protoporphyrin IX (PpIX). Prior to this, their dorsal skin was shaved and treated topically with a cream consisting of either empty or copper palmitate-encapsulated liposomal formulation. After being kept in a dimmed light environment, the rats were exposed to visible light, and inflammatory responses were inspected. Histological studies revealed that no inflammatory cells were present at the skin sites treated with liposomal cream containing copper palmitate in the Photofrin-sensitized group while no reduction in the number of inflammatory cells was observed at the skin samples treated with the empty liposomes. In conclusion, the data demonstrate the significant protective effect of topically-applied liposome-encapsulated copper palmitate against both Photofrin and ALA-induced PpIX photosensitivity.     

Liquid phase equilibria of (water + propionic acid + oleyl alcohol) ternary system at several temperatures

(Liquid–liquid) equilibrium (LLE) data are investigated for mixtures of (water + propionic acid + oleyl alcohol) at 298.15, 308.15 and 318.15 K and atmospheric pressure. The solubility curves and the tie-line end compositions of liquid phases at equilibrium were determined, and the tie-line results were compared with the data predicted by the UNIFAC method. The phase diagrams for the ternary mixtures including both the experimental and correlated tie-lines are presented. The distribution coefficients and the selectivity factors for the immiscibility region are calculated to evaluate the effect of temperature change. The reliability of the experimental tie-lines was confirmed by using Othmer–Tobias correlation. It is concluded that oleyl alcohol may serve as an adequate solvent to extract propionic acid from its dilute aqueous solutions. The UNIFAC model correlates the LLE data for 298.15, 308.15 and 318.15 K with a root mean square deviation of 5.89, 6.46, and 6.69%, respectively, between the observed and calculated mole concentrations.     

Chemoenzymatic polycondensation of <Emphasis Type="Italic">para</Emphasis>-benzylamino phenol

para-Benzylamine substituted oligophenol was synthesized via enzymatic oxidative polycondensation of 4-(benzylamino)phenol (BAP). Polymerization involved only the phenolic moiety without oxidizing the sec-amine (benzylamine) group. Chemoselective polycondensation of BAP monomer using HRP enzyme yielded oligophenol with sec-amine functionality on the side-chain. Effects of various factors including solvent system, reaction pH and temperature on the polycondensation were studied. Optimum polymerization process with the highest yield (63 %) and molecular weight (M_n = 5000, degree of polymerization ≈ 25) was achieved using the EtOH/ buffer (pH 5.0; 1: 1 vol. ratio) at 25°C in 24 h under air. Characterization of the oligomer was accomplished by ¹H NMR and ¹³C NMR, Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), ultraviolet-visible spectroscopy (UV-Vis), cyclic voltammetry (CV) and thermogravimetric analysis (TGA). The polymerization process involved the elimination of hydrogen from BAP, and phenolic-OH end groups of the oligo(BAP), confirmed using ¹H NMR and FT-IR analyses. The oligomer backbone possessed phenylene and oxyphenylene repeat units, and the resulting oligomer was highly soluble in common organic solvents such as acetone, CHCl₃, 1,4-dioxane, N,N-dimethylformamide (DMF), tetrahydrofurane (THF) and dimethylsulfoxide (DMSO). Oligo(BAP) was thermally stable and exhibited 5 % and 50 % mass loss determined by thermogravimetric analysis at 247°C and 852°C, respectively.     

Unusual Electro‐Optic Kerr Response in a Self‐Stabilized Amorphous Blue Phase with Nanoscale Smectic Clusters

We investigated the electro‐optic response in the “foggy” amorphous blue phase (BPIII) as well as in the isotropic phase. To the best of our knowledge, such a study has not yet been performed due to the very limited thermal range of BPIII. In this study, we used a single‐component chiral bent‐core liquid crystal with a self‐stabilized BPIII, which is stable over a wide temperature range. The results show that the response time is on the order of hundreds of microseconds in the isotropic phase and increases to 1–2 ms in the BPIII (at T_I?BP–T <1), then drastically increases up to a few tens of milliseconds upon further cooling in BPIII. Such an unusual behavior was explained on the basis of the high rotational viscosity and/or the existence of nanoscale smectic (Sm) clusters. The Kerr constant was also measured and found to be ～500 pm V^?2, which is the largest among bent‐core BP systems reported so far and comparable with that of polymer‐stabilized BPs.     

Free standing double walled boron nanotubes

Based on density functional calculations we propose stable structures of free standing double walled boron nanotubes in the form of two single walled boron nanotubes (SWBNTs) inside one another. Puckering of the boron sheets allows the inner atoms of the outer wall and outer atoms of the inner wall to be matched giving sp-type hybrid σ bonding between the walls. The structural stability, in the case of double walled tubes, increases as the bond interaction between the walls strengthens. All the optimized structures reported in this study are electronically conducting in good agreement with the previously calculated metallic behavior of the experimentally observed SWBNTs.     

(Liquid + liquid) equilibria of (heptane,or hexane,or cyclohexane + toluene + 1,3-dimethyl-2-imidazolidinone) ternary systems at T = 298.15 K

Experimental (liquid + liquid) equilibrium data for the mixtures of (heptane, or hexane, or cyclohexane + toluene + 1,3-dimethyl-2-imidazolidinone) were determined at T = 298.15 K and P = 101.3 kPa. The solubility (binodal) curves and tie-line end compositions are reported for the related mixtures and presented as complete phase diagrams. Distribution coefficients and separation factors were evaluated for the immiscibility region. The reliability of the experimental tie-line results was verified by using the Othmer–Tobias correlation. The experimental tie-line data were correlated by UNIQUAC model, which gave satisfactory representation for the systems. It was observed that the separation of toluene from cyclohexane is easier to achieve than from heptane and hexane.