## Abstract The kinetics of the gasβphase thermal isomerization between __trans__β and __cis__β1,2βbis(trifluoromethyl)β1,2,3,3βtetrafluorocyclopropane as well as their decomposition to __trans__β and __cis__βperfluoroβ2βbutene, respectively, and CF~2~, was studied in the temperature range of 473β5
Identification of cis- and trans-1-phenyl-2-cyano-cyclobutane in the thermal copolymerization of styrene and acrylonitrile
β Scribed by A. Ferrando; G. Goffredi; P.L. Cantini; E. Bencini
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 451 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0014-3057
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β¦ Synopsis
A complete one-and two-dimensional nuclear magnetic resonance (NMR) study was carried out on the styrene-acrylonitrile (SAN) dimer fraction of a sample of SAN thermal copolymer. A crude sample of SAN oligomers was first fractionated by distillation and then the dimers were isolated by thin-layer chromatography. The structures and stereochemistry of these compounds were then determined by NMR and the presence of disubstituted cyclobutanes was pointed out. This suggests that the Flory mechanism of initiation must be taken into account in spontaneous styrene-acrylonitrile copolymerimtion.
π SIMILAR VOLUMES
## Abstract ^13^C NMR spectra were measured for a series of ethyl __cis__β and __trans__β2β(__p__βsubstituted β phenyl) β 1 β cyclopropanecarboxylates. The effects of the __para__ substituents and the geometry on the chemical shifts are discussed.
The photolysis of SOz at 3080 A, FWHM = I50 A, and 22Β°C has been investigated in the presence of cis-and trans-CzFzH2. Quantum yield measurements for the photosensitized isomerization of cis-C2FZH2 to trans-CzFzH2 have been made for a variation in the [SO2]/[czs-C2F2H2] ratio from 0.992 to 253. The
Both cis-2-(isocyanomethyl)-5,5-dimethyl-2-oxo-4-phenyl-upon dehydration gave 1a. Thus, both (Β±)-1a and (2S,4S)-(Οͺ)-1a were prepared, and their molecular structures were 1,3,2-dioxaphosphorinane (1a) and the trans epimer 1b have been prepared as potentially useful chiral isocyano-determined by singl
This work examines the isomeric cis-trans equilibrium of the 1 ,Zdihaloethylenes in several solvents (benzene, acetonitrile and water), by means of quantum chemical calculations involving the continuum model of solvation developed by Rivail's group. The need to take into account beyond the dipole mo