Thermally Crosslinkable and Chemically Modifiable Aromatic Polyesters Possessing Pendant Propargyloxy Groups

New aromatic (co)polyesters containing pendant propargyloxy groups were synthesized by phase transfer‐catalyzed interfacial polycondensation of 5‐(propargyloxy)isophthaloyl chloride (P‐IPC) and various compositions of P‐IPC and isophthaloyl chloride with bisphenol A. FTIR and NMR spectroscopic data, respectively, revealed successful incorporation of pendant propargyloxy groups into (co)polyesters and formation of (co)polyesters with desired compositions. (Co)polyesters exhibited good solubility in common organic solvents such as chloroform, dichloromethane, and tetrahydrofuran and could be cast into transparent, flexible, and tough films from chloroform solution. Inherent viscosities and number average molecular weights of (co)polyesters were in the range 0.77–1.33 dL/g and 43,600–118,000 g/mol, respectively, indicating the achievement of reasonably high‐molecular weights. The 10% weight loss temperatures of (co)polyesters were in the range 390–420 °C, demonstrating their good thermal stability. (Co)polyesters exhibited T_g in the range 146–170 °C and T_g values decreased with increase in mol % incorporation of P‐IPC. The study of non‐isothermal curing by DSC indicated thermal crosslinking of (co)polyesters via propargyloxy groups. The utility of pendant propargyloxy group was demonstrated by post‐modification of the selected copolyester with 1‐(4‐azidobutyl)pyrene, 9‐(azidomethyl)anthracene, and azido‐terminated poly(ethyleneglycol) monomethyl ether via copper(I)‐catalyzed Huisgen 1,3‐dipolar cycloaddition reaction. FTIR and ¹H NMR spectra confirmed that click reaction was quantitative. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 588–597     

Density dependence of electron mobility in dense gases

The density (N) dependence of electron mobility (μ) in various dense gases (H₂, N₂, O₂, CO₂ and rare gases) has been calculated using a multiple-scattering approach. Deviation of the high density gas from its perfect gas behaviour has been taken into account through the temperature-dependent second virial coefficient. Multiple scattering of electrons leads to shifts in their kinetic energy and it also changes their distribution functions. This unified approach predicts both positive and negative effects. The positive (negative) effect entails on increase (decrease) of μ withN. We have assessed the available data on momentum transfer cross-sections by comparing the mobility at very low densities (Nμ)₀ with experimental results. The density dependence is studied by comparing the calculated ratioNμ)/Nμ)₀ with the observed values and other theoretical work. The Legler model which assumes a constant cross-section is inadequate for predicting the observed density dependence. We obtain good agreement with available experimental work for all the atomic and molecular species studied here.     

Line strengths and transition probabilities for allowed transitions in Fe XXI

Configuration interaction wavefunctions, transition energies, line strengths and transition probabilities for allowed transitions within then=2 complex of C-like Fe XXI have been calculated in the LS coupling scheme. We included internal, semi-internal, and all-external types of correlations. We compare our non-relativistic line strengths values with those of relativistic calculations in the Breit-Pauli approximation. The relativistic effects on line strengths are negligible for all transitions except for the transition¹ D ^e →¹ D ⁰. Experimental wavelengths are used in the calculation of transition probabilities.     

Synthesis,spectroscopic evaluation,molecular modelling,thermal study and biological evaluation of manganese(II) complexes derived from bidentate N,O and N,S donor Schiff base ligands

Manganese(II) complexes having the general composition Mn(L)₂X₂ (where L = 3‐bromoacetophenone semicarbazone, 3‐bromoacetophenone thiosemicarbazone, 1‐tetralone semicarbazone, 1‐tetralone thiosemicarbazone, flavanone semicarbazone or flavanone thiosemicarbazone and X = Cl^? or ½SO₄^2?) were synthesized. All the complexes were characterized using elemental analyses, molar conductance and magnetic moment measurements, and mass, ¹H NMR, infrared, electron paramagnetic resonance and electronic spectral studies. The molar conductance of the complexes in dimethylsulfoxide lies in the range 10–20 Ω^?1 cm² mol^?1 indicating their non‐electrolytic nature. All the complexes show magnetic moments corresponding to five unpaired electrons. The possible geometries of the complexes were assigned on the basis of electron paramagnetic resonance, electronic and infrared spectral studies. Some of the synthesized ligands and their complexes were screened for their antifungal activities against fungi Macrophomina phaseolina, Botrytis cinerea and Phoma glomerata using the food poison technique and their antibacterial activities against Xanthomonas campestris pv. campestris and Ralstonia solanacearum using the paper disc diffusion method. They showed appreciable activities.     

Optoelectronic and biological quantification of semi-conducting,crimson europium chelates with fluorinated β-keto acid and N-donor ancillary ligands

Research on Chemical Intermediates - Five luminescent ternary and one binary Europium(III) complexes were synthesised with β-keto acid as primary ligand and neocuproine(neo),...     

Quantitative Analysis of Flavonoids in Annona squamosa Leaf Extracts and Its Pellet Formulation by Validated High-Performance Thin-Layer Chromatographic Technique

JPC – Journal of Planar Chromatography – Modern TLC - Annona squamosa, commonly known as custard apple, possesses various medicinal properties such as antimicrobial, insecticidal,...     

Catalytic dioxygen activation by Co(II) complexes employing a coordinatively versatile ligand scaffold

The ligand bis(2-isobutyrylamidophenyl)amine has been prepared and used to stabilize both mononuclear and dinuclear cobalt(II) complexes. The nuclearity of the cobalt product is regulated by the deprotonation state of the ligand. Both complexes catalytically oxidize triphenylphosphine to triphenylphosphine oxide in the presence of O(2).     

The Relationship Between VHI Scores and Specific Acoustic Measures of Mildly Disordered Voice Production

This study was designed to examine the relationship between the Voice Handicap Index (VHI) and acoustic measures of voice samples common in clinical practice. Fifty participants, 38 women and 12 men, ranging in age from 19 to 80 years, with a mean age of 49 years, served as participants. Of these 50 participants, 17 participants could be included in the acoustic analysis of voice based on measures of error calculated with the TF32 software. All participants completed the VHI and provided voice samples including three trials of the sustained vowel /A/ at a comfortable loudness level as well as a connected speech sample consisting of the Zoo Passage. Acoustic measures were made with TF32 and Cool Edit software and included fundamental frequency, jitter %, shimmer %, signal-to-noise ratio, mean root-mean-square intensity, fundamental frequency standard deviation, aphonic periods, and breath groups. Results indicate that these measures were not predictive of overall VHI score, and no cohesive or predictable pattern was identified when comparing individual measures with overall VHI or with each subscale item. Likely contributions to this lack of correlation and subsequent clinical implications are discussed, as well as the direction for further research.