Solution and emulsion behavior of highly soluble carboxylate surfactants with α-substituted phenoxy group

2020 ◽  
Vol 299 ◽  
pp. 112130
Author(s):  
Mingzhu Yang ◽  
Binglei Song ◽  
Delun Du ◽  
Xiaomei Pei ◽  
Zhenggang Cui
Keyword(s):  
Phenoxy Group

scholarly journals Study of Kinetics, Equilibrium and the Influence of Steric Effects on Proton-Transfer in the Reactions of 2, 2, 4- and 2, 6- Substituted Anilines with 2-Phenoxy-3,5-dinitropyridine in DMSO

2010 ◽  
Vol 7 (1) ◽  
pp. 253-259 ◽  
Author(s):  
Basim H. Asghar
Keyword(s):  
Proton Transfer ◽  
Steric Effect ◽  
Nucleophilic Attack ◽  
Steric Effects ◽  
Substituted Anilines ◽  
Phenoxy Group ◽  
Kinetics Studies ◽  
Zwitterionic Intermediate ◽  
Rate Limiting ◽  
Step Mechanism

Kinetic and equilibrium results for the reactions of 2-phenoxy-3,5-dinitropyridine (1), with a series of 2, 2, 4- and 2, 6- substituted anilines (2a-f), in the presence of DABCO in DMSO are reported. The reactions yield the 2-anilino derivatives (5), without the accumulation of intermediates. Kinetics studies are compatible with a two-step mechanism involving initial nucleophilic attack by amine at the ring carbon substituted by phenoxy group followed by either base-catalyzed or uncatalyzed conversion to the product. The base-catalyzed pathway is likely to involve rate-limiting proton-transfer from the zwitterionic intermediate to base. This work indicates a steric effect to proton transfer in reactions involving 2, 6-disubstituted anilines. The results were compared with those for reactions of 1, 3, 5-trinitrobenzene with anilines.

Discotic liquid crystals of transition metal complexes 38†: peripheral chain substituent position effect on columnar mesophase and stacking structures of novel phthalocyanine-based liquid crystals

2007 ◽  
Vol 11 (07) ◽  
pp. 503-512 ◽  
Author(s):  
Masahiro Ichihara ◽  
Ayumi Suzuki ◽  
Kazuaki Hatsusaka ◽  
Kazuchika Ohta
Keyword(s):  
Liquid Crystals ◽  
Position Effect ◽  
Optical Microscope ◽  
Central Core ◽  
Ortho Position ◽  
Discotic Liquid Crystals ◽  
Isotropic Liquid ◽  
X Ray ◽  
Phenoxy Group ◽  
Columnar Mesophases

In order to clarify the peripheral chain substitution position effect on columnar mesophase and stacking structures, we have synthesized three novel series of discotic liquid crystals (1-3) having octakis(phenoxy)phthalocyaninato copper(II) as a central core and one peripheral chain at the para position (1), meta position (2) or ortho position (3) of each phenoxy group, and three more novel series of discotic liquid crystals (4-6) having the same central core and two peripheral chains at para and meta positions (4), meta and meta positions (5) or ortho and meta positions (6) of each phenoxy group. Their columnar mesophase and stacking structures were investigated with a polarizing optical microscope, a differential scanning calorimeter and a temperature-dependent X-ray diffractometer. According to the results, their columnar mesophase and stacking structures strongly depended on the peripheral chain substitution positions and the number of peripheral chains. Derivatives 3 and 5 are viscous isotropic liquid at room temperature. Derivatives 1, 2, 4 and 6 exhibit various kinds of columnar mesophases: 1 Colhd; 2 Colhd and Colho; 4 Colhd, Colrd(P21/a), Coltet.d and Cub ( Pn [ three bar ] m ); 6 Colhd, Colrd(P21/a) and Colrd(X). Moreover, derivatives 1, 4 and 6 exhibit disordered columnar mesophases. However, derivative 2 only exhibits an ordered columnar mesophase and its X-ray diffraction pattern shows a sharp reflection corresponding to a very short intracolumnar stacking distance of 3.33 Å. Thus, we can drastically change the mesophase and stacking structures by the peripheral chain substitution positions and the number of peripheral chains at each phenoxy group. This is a new way of controlling mesomorphic structure.

scholarly journals Anionic iodotyrosine residues are required for iodothyronine synthesis

1998 ◽  
pp. 227-231 ◽  
Author(s):  
JJ de Vijlder ◽  
MT den Hartog
Keyword(s):  
Ph Dependence ◽  
Coupling Reaction ◽  
Product Formation ◽  
Hydroxyl Group ◽  
Dissociation Curve ◽  
Anion Formation ◽  
Phenoxy Group ◽  
A Value ◽  
Gradual Loss

Biosynthesis of iodothyronines in thyroglobulin occurs by oxidative coupling of two iodotyrosine residues catalyzed by thyroperoxidase. To study the mechanism of iodothyronine formation, iodine-free thyroglobulin was non-enzymatically iodinated and after removal of non-incorporated iodide, incubated with lactoperoxidase and glucose oxidase between pH 4 and 9. The amount of thyroxine (T4). 3,5,3'-tri-iodothyronine (T3), 3,3',5'-tri-iodothyronine (rT3) and 3,3'-di-iodothyronine (T2) formed was measured by radioimmunoassays after hydrolysis of thyroglobulin. T4 is synthesized out of two di-iodotyrosine (DIT) residues in thyroglobulin. The pH dependence of T4 formation fits the dissociation curve of the DIT phenoxy group (pKa 6.5). The formation of T2, synthesized out of two mono-iodotyrosine (MIT) residues, shows a quite different pH dependence. Below pH 6, T2 synthesis could not be observed, while above pH 7.4 a relatively large increase occurred. The values up to pH 8 fitted the dissociation curve of the MIT-phenoxy group with a pKa of 8.7. The gradual loss in enzymatic activity of peroxidase and oxidase in the reaction made the values obtained above pH 8 unreliable. The importance of the ionization of the phenoxy group for the coupling reaction was further consolidated by showing that the pH-dependent oxidation of 2-methoxy-phenol (guaiacol) had 50% maximal product formation at pH 7, a value concordant with pKa 7.0 for the ionization of the phenoxy group of this agent. T3 and rT3 synthesis followed mainly the ionization curve of the inner-ring hydroxyl group, indicating that this ring has the greatest influence on hormonogenesis. Since anion formation facilitates the removal of an electron under oxidative conditions, the pH dependence agrees with the involvement of phenoxy radicals in iodothyronine synthesis, a process that most likely also occurs in vivo since it is mainly T4 that is formed in thyroglobulin.

Synthesis, characterization, and optical and surface properties of (4-(trifluoromethylthio)phenoxy) copper(ii) phthalocyanine

2018 ◽  
Vol 42 (8) ◽  
pp. 6013-6022 ◽  
Author(s):  
Armağan Günsel ◽  
Ahmet T. Bilgiçli ◽  
Hasan Pişkin ◽  
Nagihan Çaylak Delibaş ◽  
M. Nilüfer Yarasir ◽  
...  
Keyword(s):  
Surface Properties ◽  
Copper Phthalocyanine ◽  
Synthesis And Characterization ◽  
Phenoxy Group

This paper reports on the synthesis and characterization of a non-peripherally tetra-substituted copper phthalocyanine containing a 4-(trifluoromethylthio)phenoxy group.

Observations regarding the crystal structures of non-halogenated phenoxyboronsubphthalocyanines having para substituents on the phenoxy group

CrystEngComm ◽  
2011 ◽  
Vol 13 (3) ◽  
pp. 914-919 ◽  
Author(s):  
Andrew S. Paton ◽  
Graham E. Morse ◽  
Alan J. Lough ◽  
Timothy P. Bender
Keyword(s):  
Crystal Structures ◽  
Phenoxy Group

scholarly journals 2-(4-Hydroxyphenyl)-4,6-dimethyl-2,3-dihydropyrimidin-1-ium acetate

IUCrData ◽  
2018 ◽  
Vol 3 (7) ◽  
Author(s):  
Kedila Rasheeda ◽  
Seranthimata Samshuddin ◽  
Phadke N. Swathi ◽  
Vijaya D. P. Alva ◽  
Joel T. Mague ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Phenoxy Group ◽  
Compound C

In the title compound, C12H15N2O+·C2H3O2 −, the phenoxy group is nearly perpendicular [80.73 (11)°] to the dihydropyrimidinium ring. In the crystal, O—H...O, N—H...O and C—H...O hydrogen bonds form corrugated layers parallel to the ac plane.

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