The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Eric W. Kaler - One of the best experts on this subject based on the ideXlab platform.
-
Influence of pH on the micelle-to-vesicle transition in aqueous mixtures of sodium dodecyl Benzenesulfonate with histidine.
The journal of physical chemistry. B, 2005Co-Authors: Yamaira I. González, Hisanori Nakanishi, Maria Stjerndahl, Eric W. KalerAbstract:Small unilamellar vesicles (∼100 nm in diameter) form spontaneously in aqueous mixtures of histidine and sodium dodecyl Benzenesulfonate. By manipulating pH, a gradual transition from micelles to v...
B. Šoptrajanov - One of the best experts on this subject based on the ideXlab platform.
-
A gradient-corrected density functional study of structure, harmonic vibrational frequencies and charge distribution of Benzenesulfonate anion on the ground-state potential energy surface
Journal of Molecular Structure, 2000Co-Authors: Lj Pejov, Mirjana Ristova, B. ŠoptrajanovAbstract:Abstract A density functional study of the structure, harmonic vibrational force field, and charge distribution of Benzenesulfonate anion combined with a solid-state FT-IR study of sodium Benzenesulfonate is presented. Two combinations of exchange/correlation functionals (BLYP and B3LYP) were employed within the quantum chemical approach, using the standard double-zeta quality 6-31+G(d) basis set for orbital expansion. The DFT predicted structure of the studied species is in a very good agreement with the available crystallographic data ( significantly better in comparison with our previous HF SCF results for Benzenesulfonate and 4-methylBenzenesulfonate anions). Both the B3LYP and BLYP/6-31+G(d) vibrational analyses of the Benzenesulfonate anion confirmed our previously proposed reassignments of several vibrational bands of this system based on the HF SCF/6-31+G(d) vibrational force field. The B3LYP predicted vibrational frequencies are superior to the BLYP ones. The Mulliken population analysis predicts a strong anionic charge delocalization over the phenyl ring (−0.54 and −0.56 e , B3LYP and BLYP levels correspondingly), whereas according to the electrostatic potential derived schemes, it is mainly localized within the SO 3 group. The latter result seems to be more in line both with the observed hydrogen bonding in the solid crystalline hydrates and with chemical intuition.
-
Ab initio quantum chemical and experimental study of structure, harmonic vibrational frequencies and internal Ph–SO 3 torsion of Benzenesulfonate anion
Journal of Molecular Structure, 2000Co-Authors: Lj Pejov, Mirjana Ristova, Z Zdravkovski, B. ŠoptrajanovAbstract:Abstract A combined quantum chemical and experimental study of the structure, harmonic vibrational frequencies, charge distribution and internal torsional motion of Benzenesulfonate anion was performed. The geometry of the anion was optimized at the HF/3-21+G(d) and HF/6-31+G(d) levels of theory, followed by numerical harmonic vibrational analysis. Furthermore, the FT-IR spectra of several metal Benzenesulfonate salts were recorded. The computed structural parameters of the anion at both levels of theory are in very good agreement with the X-ray data. Regarding the vibrational analysis, the HF/6-31+G(d) force field is significantly superior over the HF/3-21+G(d). On the basis of the HF/6-31+G(d) vibrational analysis, several important reassignments of the IR bands owing to the Benzenesulfonate anion are suggested. The larger basis set methodology gives the correct order of conformational stabilities (staggered vs. eclipsed anion conformation), while the lower basis reproduces the experimental data only upon inclusion of the zero-point energy corrections. On the basis of ab initio HF/6-31+G(d) energetics, the torsional energy levels of the Ph–SO 3 rotor were computed within a one-dimensional approach, diagonalizing the torsion Hamiltonian in the free-rotor basis. Both the Mulliken and the NPA charge-partitioning schemes predict a strong delocalization of the anionic charge over the phenyl ring, while the electrostatic potential based schemes (CHelp, CHelpG and MK) predict only a slight delocalization.
Dan Fei - One of the best experts on this subject based on the ideXlab platform.
-
micellization in binary biosurfactant synthetic surfactant systems effects of temperature and hydrophobic group structure of alkyl Benzenesulfonate
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2018Co-Authors: Lingling Kong, Hong-ze Gang, Charl J. Jafta, Zijun Wang, Dan FeiAbstract:Abstract Micellization mechanism of biosurfactant/synthetic surfactant systems is essential in predicting their industrial applications. Biosurfactant, [Glu1,Asp5]-C15 surfactin, mixing with three isomers of sodium cetyl Benzenesulfonate (SCBS) with Benzenesulfonate attached at the 2nd, 5th, 8th carbon on the alkyl chain (abbreviated as 2-SCBS, 5-SCBS, and 8-SCBS), constituted the binary biosurfactant/synthetic surfactant systems in this work. Effects of mixing ratios, temperature, and hydrophobic structures of SCBS on micellization process were investigated by surface tensiometry, steady state fluorescence measurements, dynamic light scattering, and small angle neutron scattering. The results showed that at 60 ℃ synergism in micellization occurred in surfactin/2-SCBS and surfactin/5-SCBS binary systems, while antagonism appeared in surfactin/8-SCBS binary systems. Molecular interaction in mixed micelle at 60 ℃ turned from strong attractive to strong repulsive with the Benzenesulfonate moving from the end to the middle of the alkyl chain. Surfactin exhibited weak interaction with both 5-SCBS and 8-SCBS at 25 ℃. Mixed surfactin/2-SCBS micelles were formed in spherical cylinders with more hydrophobic core and within 66 A. Mixed surfactin/5-SCBS micelles and mixed surfactin/8-SCBS micelles showed similar morphology evolutions at 25 ℃, long elliptical cylinders transformed into small spherical cylinder by reducing both length and radius ratio of cross section with increasing surfactin mole fraction.
-
Micellization in binary biosurfactant/synthetic surfactant systems: Effects of temperature and hydrophobic group structure of alkyl Benzenesulfonate
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2018Co-Authors: Lingling Kong, Hong-ze Gang, Wang Zijun, Charl J. Jafta, Dan FeiAbstract:Abstract Micellization mechanism of biosurfactant/synthetic surfactant systems is essential in predicting their industrial applications. Biosurfactant, [Glu1,Asp5]-C15 surfactin, mixing with three isomers of sodium cetyl Benzenesulfonate (SCBS) with Benzenesulfonate attached at the 2nd, 5th, 8th carbon on the alkyl chain (abbreviated as 2-SCBS, 5-SCBS, and 8-SCBS), constituted the binary biosurfactant/synthetic surfactant systems in this work. Effects of mixing ratios, temperature, and hydrophobic structures of SCBS on micellization process were investigated by surface tensiometry, steady state fluorescence measurements, dynamic light scattering, and small angle neutron scattering. The results showed that at 60 ℃ synergism in micellization occurred in surfactin/2-SCBS and surfactin/5-SCBS binary systems, while antagonism appeared in surfactin/8-SCBS binary systems. Molecular interaction in mixed micelle at 60 ℃ turned from strong attractive to strong repulsive with the Benzenesulfonate moving from the end to the middle of the alkyl chain. Surfactin exhibited weak interaction with both 5-SCBS and 8-SCBS at 25 ℃. Mixed surfactin/2-SCBS micelles were formed in spherical cylinders with more hydrophobic core and within 66 A. Mixed surfactin/5-SCBS micelles and mixed surfactin/8-SCBS micelles showed similar morphology evolutions at 25 ℃, long elliptical cylinders transformed into small spherical cylinder by reducing both length and radius ratio of cross section with increasing surfactin mole fraction.
Yamaira I. González - One of the best experts on this subject based on the ideXlab platform.
-
Influence of pH on the micelle-to-vesicle transition in aqueous mixtures of sodium dodecyl Benzenesulfonate with histidine.
The journal of physical chemistry. B, 2005Co-Authors: Yamaira I. González, Hisanori Nakanishi, Maria Stjerndahl, Eric W. KalerAbstract:Small unilamellar vesicles (∼100 nm in diameter) form spontaneously in aqueous mixtures of histidine and sodium dodecyl Benzenesulfonate. By manipulating pH, a gradual transition from micelles to v...
Min Wang - One of the best experts on this subject based on the ideXlab platform.
-
Copper Benzenesulfonate-Promoted One-Pot Synthesis of
2013Co-Authors: Min Wang, Jilei WanAbstract:Carbamatoalkyl-2-naphthol derivatives were obtained from one-pot three-component condensation of 2-naphthol, aldehydes, and carbamates catalyzed by copper Benzenesulfonate under thermal solvent-free conditions. The ef- fects of amount of catalyst, reaction temperature and solvent on the products yields were investigated. Experimental results showed that only 2 mol% copper benzenesulfoante was enough to induce the conversion. After reaction, catalyst could be recycled four times without distinct loss of catalytic activity. The structures of all products were characterized by 1 H NMR, 13 C
-
efficient synthesis of mono and disubstituted 2 3 dihydroquinazolin 4 1 h ones using copper Benzenesulfonate as a reusable catalyst in aqueous solution
Monatshefte Fur Chemie, 2012Co-Authors: Min Wang, Yan Liang, T T Zhang, Jing J GaoAbstract:Copper Benzenesulfonate was found to be an effective catalyst for one-pot three-component cyclocondensation of isatoic anhydride, aromatic aldehydes, and ammonium salts or primary amines in aqueous solution to afford the corresponding mono- and disubstituted 2,3-dihydroquinazolin-4(1H)-ones in good yields. The catalyst is reusable and could be recycled for several times without distinct decrease in its efficiency.
-
Zinc Benzenesulfonate–Promoted Eco-Friendly and Efficient Synthesis of 1-Amidoalkyl-2-naphthols
Synthetic Communications, 2012Co-Authors: Min Wang, Zhi Guo Song, Yan LiangAbstract:Abstract A three-component, one-pot condensation of 2-naphthol, aldehydes, and amides catalyzed by zinc Benzenesulfonate gives 1-amidoalkyl-2-naphthols in good yields at 80 °C under solvent-free conditions. The catalytic activities of zinc benzenesulfoante and 12 other metal Benzenesulfonates were compared. After the reaction, zinc benzenesulfoante can be recycled several times without distinct loss of catalytic activity.
-
zinc Benzenesulfonate promoted eco friendly and efficient synthesis of 1 amidoalkyl 2 naphthols
Synthetic Communications, 2012Co-Authors: Min Wang, Zhi Guo Song, Yan LiangAbstract:Abstract A three-component, one-pot condensation of 2-naphthol, aldehydes, and amides catalyzed by zinc Benzenesulfonate gives 1-amidoalkyl-2-naphthols in good yields at 80 °C under solvent-free conditions. The catalytic activities of zinc benzenesulfoante and 12 other metal Benzenesulfonates were compared. After the reaction, zinc benzenesulfoante can be recycled several times without distinct loss of catalytic activity.
-
Metal Benzenesulfonates/Acetic Acid Mixtures as Novel Catalytic Systems: Application to the Protection of a Hydroxyl Group.
ChemInform, 2011Co-Authors: Min Wang, Jingjing Gao, Zhi Guo SongAbstract:A surprising synergistic effect is observed when metal Benzenesulfonates (Co, Al, Ni etc.) and acetic acid are used as catalytic system for the tetrahydropyranylation of alcohols or phenols.