Kinetics and Process Parameter Studies in Highly Selective Air Oxidation of Side-Chain Alkyl Groups in Picolines, 2-Methylnaphthalene, and Pseudocumene

1999 ◽  
Vol 3 (3) ◽  
pp. 227-231 ◽  
Author(s):  
Sudip Mukhopadhyay ◽  
Sampatraj B. Chandalia
Keyword(s):  
Process Parameter ◽  
Side Chain ◽  
Air Oxidation ◽  
Alkyl Groups

scholarly journals Antimicrobial Porous Surfaces Prepared by Breath Figures Approach

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1266 ◽  
Author(s):  
Alexandra Muñoz-Bonilla ◽  
Rocío Cuervo-Rodríguez ◽  
Fátima López-Fabal ◽  
José Gómez-Garcés ◽  
Marta Fernández-García
Keyword(s):  
Block Copolymers ◽  
Side Chain ◽  
Porous Films ◽  
Narrow Pore Size Distribution ◽  
Breath Figures ◽  
Gram Positive Bacteria ◽  
Alkyl Groups ◽  
Porous Surfaces ◽  
Cationic Copolymers ◽  
Ordered Porous

Herein, efficient antimicrobial porous surfaces were prepared by breath figures approach from polymer solutions containing low content of block copolymers with high positive charge density. In brief, those block copolymers, which were used as additives, are composed of a polystyrene segment and a large antimicrobial block bearing flexible side chain with 1,3-thiazolium and 1,2,3-triazolium groups, PS54-b-PTTBM-M44, PS54-b-PTTBM-B44, having different alkyl groups, methyl or butyl, respectively. The antimicrobial block copolymers were blended with commercial polystyrene in very low proportions, from 3 to 9 wt %, and solubilized in THF. From these solutions, ordered porous films functionalized with antimicrobial cationic copolymers were fabricated, and the influence of alkylating agent and the amount of copolymer in the blend was investigated. Narrow pore size distribution was obtained for all the samples with pore diameters between 5 and 11 µm. The size of the pore decreased as the hydrophilicity of the system increased; thus, either as the content of copolymer was augmented in the blend or as the copolymers were quaternized with methyl iodide. The resulting porous polystyrene surfaces functionalized with low content of antimicrobial copolymers exhibited remarkable antibacterial efficiencies against Gram positive bacteria Staphylococcus aureus, and Candida parapsilosis fungi as microbial models.

Assessing the Effect of Ligand Proximity on Chiroptical and Other Properties in Cobalt(III) Model, Tyrosine-Like Complexes

1995 ◽  
Vol 60 (12) ◽  
pp. 2097-2106 ◽  
Author(s):  
František Jursík ◽  
Ronald D. Archer
Keyword(s):  
Amino Acid ◽  
Inductive Effect ◽  
Lewis Acidity ◽  
Side Chain ◽  
Ground State Structure ◽  
Amino Acid Side Chain ◽  
State Structure ◽  
Reduction Potentials ◽  
Alkyl Groups ◽  
C Nmr

A series of new cobalt(III) octahedral complexes of the general formula Na[Co(ohb-aa)2] (ohb-aa = N-(o-hydroxybenzyl)amino acid anion); amino acid = glycine, (S)-α-alanine, α-aminoisobutyric acid, (S)-valine, (S)-norvaline and (S)-leucine) were prepared by the charcoal catalyzed reaction of the appropriate ligand with [Co(NH3)6]3+ in alkaline aqueous solution. Complexes obtained have, regardless of the amino acid used, the same facial all-trans symmetry (CoN2O4 chromophore) with the vicinal effects as the entire source of the optical activity. 13C NMR spectra reveal that the leucine derivative has, due to the steric reasons, a different ground state structure. Absorption maxima reflect a positive inductive effect from the amino acid side chain carbon atoms. Complexes of the ligands bearing electrophobic alkyl groups exhibit more negative E1/2 in comparison with the glycine derivative, reduction of which occurs at a more positive potential. Reduction potentials do not correlate with cobalt(III) Lewis acidity modulated by ligands.

The impact of vinylene bridges and side chain alkyl groups on the solid state structures of tricyanovinyl-substituted thiophenes

CrystEngComm ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 128-132
Author(s):  
Phuong-Truc T. Pham ◽  
Victor G. Young ◽  
Mamoun M. Bader
Keyword(s):  
Solid State ◽  
Side Chain ◽  
Alkyl Groups ◽  
The Impact ◽  
Solid State Structures

The goal of this work is to examine the solid state structures of compounds that have been designed for increased conjugation and solubility, as these factors are important if these compounds are to be used in the solid state.

Phenomenological Kinetics of Isothermal Wet Air Oxidation: Operating Severity Factor and Recalcitrance Index

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Khaled Belkacemi ◽  
Safia Hamoudi
Keyword(s):  
Phenolic Compounds ◽  
Carboxylic Acids ◽  
Molecular Size ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Severity Factor ◽  
Alkyl Groups ◽  
Structural Parts ◽  
Oxidation Efficiency ◽  
Recalcitrance Index

In the present investigation, the kinetics governing wet air oxidation (WAO) of organic pollutants is modeled by two distinct parallel kinetic terms corresponding to a readily oxidizable and a recalcitrant structural parts of the pollutant molecule involving the concept of thermodynamic severity factor. The developed model was successfully applied to several classes of organic water pollutants including phenolic compounds as well as mono- and di-carboxylic acids. In the offshoot of the model, a recalcitrance index was proposed classifying the pollutant molecules according to their resistance to oxidation. For the carboxylic acids, it was found that the recalcitrance towards WAO was inversely correlated to the molecular size and weight. Acetic acid proved to be the more recalcitrant component. As for the phenolic compounds, the oxidation efficiency was shown to be affected by the nature of the substitutents present on the phenolic ring. The electron donating substitutents such as alkyl groups (CH3 or –C2H5) confer to the molecule an enhanced reactivity towards WAO. On the contrary, electron-accepting substitutents, such as methoxy groups, lower the oxidation and consequently enhance the recalcitrance.

Thermal Behaviors of N-Octadecylated Poly( Ethyleneimine) with Different Grafting Ratios

2011 ◽  
Vol 332-334 ◽  
pp. 2085-2088 ◽  
Author(s):  
Yi Ping Yin ◽  
Hai Feng Shi ◽  
Li Juan Li ◽  
Xing Xiang Zhang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Behavior ◽  
Chemical Structure ◽  
Side Chain ◽  
Scanning Calorimetry ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Grafting Ratio ◽  
Grafting Density ◽  
Alkyl Groups ◽  
Linear Increment

A series of N-octadecylated polyethyleneimine (PEI18C) comblike polymers with different grafting ratios, through N-alkylation method, have been successfully prepared. The chemical structure and thermal behavior of PEI18C comblike polymers with different grafting ratios has been characterized by Fourier transformed infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Experimental shows that C18 alkyl groups have been successfully grafted onto PEI backbones, and the thermal behavior of PEI18C comblike polymers with different grafting ratios exhibit the linear increment with the grafting ratio of alkyl groups. It can be attributed to the effect of the grafting density of alkyl side groups along PEI backbones. The detailed investigation and discussion is carried out from the viewpoint of side chain crystallization and molecular packing behaviors.

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