Selective hydroxylation of methyl groups by platinum salts in aqueous medium. Direct conversion of ethanol to ethylene glycol

1990 ◽  
Vol 112 (14) ◽  
pp. 5628-5629 ◽  
Author(s):  
Jay A. Labinger ◽  
Andrew M. Herring ◽  
John E. Bercaw
Keyword(s):  
Ethylene Glycol ◽  
Aqueous Medium ◽  
Direct Conversion ◽  
Methyl Groups ◽  
Platinum Salts ◽  
Selective Hydroxylation

The synthesis and stereochemistry of the ternary cobalt(III) complex with a stereospecific ligand derived from (S)-leucine

1986 ◽  
Vol 51 (2) ◽  
pp. 318-326 ◽  
Author(s):  
Milan Strašák ◽  
Pavol Novomeský
Keyword(s):  
Ir Spectroscopy ◽  
Aqueous Medium ◽  
Absorption Spectroscopy ◽  
Absolute Configuration ◽  
Nmr Spectra ◽  
Methyl Groups ◽  
Electron Absorption Spectroscopy ◽  
Electron Absorption ◽  
C Nmr

A new stereospecific ligand, ethylenediamine-N,N'-di(S)-α-isocapronic acid, was synthesized by condensation of (S)-leucine with 1,2-dibromoethane in alkaline aqueous medium. It follows from the 1H and 13C NMR spectra that the terminal methyl groups are chemically and magnetically nonequivalent. Of the four theoretically possible isomers of the ternary cobalt (III) complex with ethylenediamine, separation on catex yielded only one, whose absolute configuration was determined by a combination of 1H and 13C NMR, electron absorption spectroscopy and CD and IR spectroscopy.

Visible light-induced direct conversion of aldehydes into nitriles in aqueous medium using Co@g-C3N4 as photocatalyst

2019 ◽  
Vol 119 ◽  
pp. 76-81 ◽  
Author(s):  
Fooleswar Verma ◽  
Prashant Shukla ◽  
Smita R. Bhardiya ◽  
Manorama Singh ◽  
Ankita Rai ◽  
...  
Keyword(s):  
Visible Light ◽  
Aqueous Medium ◽  
Direct Conversion

Short oligo(ethylene glycol) chain incorporated thermoresponsive microgels: from structural analysis to modulation of solution properties

Soft Matter ◽  
2020 ◽  
Vol 16 (33) ◽  
pp. 7845-7859
Author(s):  
Priyanshi Agnihotri ◽  
Ritu Raj ◽  
Dinesh Kumar ◽  
Abhijit Dan
Keyword(s):  
Structural Analysis ◽  
Ethylene Glycol ◽  
Aqueous Medium ◽  
Solution Properties ◽  
Glycol Methacrylate ◽  
Colloidal Properties

This work reports the synthesis, structural analysis and colloidal properties in aqueous medium of thermoresponsive PNIPAM-based microgels incorporating short oligo(ethylene glycol) methacrylate comonomers.

Detection of Interfacial Structures of Poly(ethylene glycol), Poly(propylene glycol) and Their Copolymers at Liquid/Solid Interfaces Using Sum Frequency Generation Vibrational Spectroscopy

2003 ◽  
Vol 790 ◽  
Author(s):  
Chunyan Chen ◽  
Jie Wang ◽  
Mark A. Even ◽  
Zhan Chen
Keyword(s):  
Ethylene Glycol ◽  
Vibrational Spectroscopy ◽  
Molecular Level ◽  
Fused Silica ◽  
Methyl Groups ◽  
Poly Ethylene Glycol ◽  
Sum Frequency ◽  
Interfacial Structures ◽  
Poly Ethylene ◽  
Poly Propylene

ABSTRACTWe have applied sum frequency generation (SFG) vibrational spectroscopy, a submonolayer surface sensitive analytical technique, to study interfacial structures of poly (ethylene glycol) (PEG), poly (propylene glycol) (PPG), their solutions, their copolymers, and copolymer solutions while contacting different media including air, fused silica, and various polymers.For the first time, conformations of polyether materials at various interfaces have been shown at the molecular level in situ. Depending on the hydrophobicity of the solid contacting media, the liquid polymers PEG and PPG show different conformations at different interfaces, which can be correlated to molecular interactions at these interfaces. The favorable interaction between hydrophobic media and the hydrophobic segments, methylene or methyl groups, of polyethers causes an ordered conformation with these groups standing up at the interface. The unfavorable interaction between hydrophilic media and hydrophobic segments of the polyethers induces interfacial methylene or methyl groups to have a random structure or to lie down at the interfaces, indicated by the weakening or even absence of SFG signals. For comparison, interfaces between aqueous PEG or PPG solutions and air, polystyrene (PS), poly(methyl methacrylate) (PMMA), and fused silica have also been investigated. In addition, we have studied conformations of pluronics at various interfaces, showing that different blocks have different interface activities. The interfaces are always dominated by the PPG segments. The studies on molecular level interfacial structures of PEG, PPG and pluronics will help us to understand and control the interfacial behavior of liquids at interfaces.

Direct conversion of cellulose into ethanol catalysed by a combination of tungstic acid and zirconia-supported Pt nanoparticles

2019 ◽  
Vol 55 (30) ◽  
pp. 4303-4306 ◽  
Author(s):  
Haiyan Song ◽  
Pan Wang ◽  
Shi Li ◽  
Weiping Deng ◽  
Yanyun Li ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Pt Nanoparticles ◽  
Direct Conversion ◽  
Tungstic Acid

Direct conversion of cellulose to ethanol is achieved by using a combination of H2WO4 and Pt/ZrO2 catalysts in an aqueous medium.

Deprotective activity of nanosized globular partially quaternized poly(tertiary amine)s in peptide synthesis

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Pascal Chapon ◽  
Jean Coudane ◽  
Henri Garreau ◽  
Michel Vert ◽  
Jean Alain Ferhentz ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Aqueous Medium ◽  
Room Temperature ◽  
Heterogeneous Systems ◽  
Protecting Groups ◽  
Hydrophobic Core ◽  
Poly Ethylene Glycol ◽  
Solid Supports ◽  
Spacer Arm ◽  
Poly Ethylene

AbstractBifunctional polybases of the partially quaternized poly[thio-1-(N,Ndiethylaminomethyl) ethylene] type (Q(PTDAE),X, with X = percentage of N-quaternization) are able to catalyze various reactions including lipophilic reagents temporarily entrapped in the hydrophobic core of the globules. In this contribution it is shown that benzyloxycarbonyl (Z) and fluoromethyloxycarbonyl (Fmoc) protecting groups of peptides are cleaved at room temperature in a few minutes in an aqueous medium at pH 7,4. Deprotection was also effective when peptides were attached to solid supports of the Merrifield type provided a hydrophilic spacer arm of the poly(ethylene glycol)-type was inserted between beads and the built up peptide moieties. However, unhooking was observed when the hydrophilic spacerpeptide bond was an ester but not when it was of the amide type. The work shows that Q(PTDAE),X globules exhibit enzyme-like activity in a homogeneous aqueous medium and in heterogeneous systems as well.

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