𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Carbon skeletal rearrangements in 2-phenylthiophene and 2,5-diphenylthiophene under conditions of electron-impact

✍ Scribed by W. D. Weringa; H. J. M. Sinnige; Matthijs J. Janssen

Publisher
John Wiley and Sons
Year
1971
Tongue
English
Weight
553 KB
Volume
5
Category
Article
ISSN
1076-5174

No coin nor oath required. For personal study only.

✦ Synopsis

The mass spectra of %-labelled 2-phenylthiophenes and 2,5-diphenylthiophenes were studied. The label distributions for the [HCS]+, [C,H,S]+., [C,H,]+., [C&I,]+ and [C,H5]S+ ions from 2-phenylthiophene and the [HCS]+, [C,H,]+, [C&Sj+, [C8H6S]+. and [C,,H,,]+ ions from 2,s-diphenylthiophene were interpreted in terms of both carbon skeletal rearrangements in the thiophene ring and migration of the phenyl substituent. The degree of carbon scrambling in the thiophene ring appeared to be almost independent of the electron beam energy. The formation of some of the fragment ions studied seems to be so fast that no carbon scrambling could be detected at all; in neither case was complete scrambling of the carbon atoms of the thiophene ring observed. I N T R O D U C T I O N * F. de Jong, personal communication. I399 * For the synthesis of these labelled thiophenes, see Ref. Ib. * Collision induced metastables may possibly show the formation of [ilCS]+ from [MI+.. This technique was, however, not available to us.

📜 SIMILAR VOLUMES

Benzylic cleavage and McLafferty rearran
Benzylic cleavage and McLafferty rearrangement under electron ionization conditions in the fragmentation of 5,6-dialkyl-2,4-diarylpyrimidines
✍ R. Martínez Alvarez; A. Herrera Fernández; M. Chioua; P. Ramiro Pérez; N. Villal 📂 Article 📅 1999 🏛 John Wiley and Sons 🌐 English ⚖ 138 KB 👁 2 views

Several 5,6-dialkyl-2,4-diarylpyrimidines were prepared and their electron ionization (EI) mass spectra reported. The benzylic cleavage takes place easily together with an important McLafferty rearrangement. The involvement of the nitrogen atom appears to be important in the fragmentation of 5-methy

Elimination and rearrangement reactions
Elimination and rearrangement reactions in the electron impact ionization mass spectrometry of 2,4,5,5-tetrasubstituted 1,2,4-triazolidine-3-thiones
✍ Kalevi Pihlaja; Esa Mäki; Klaus Schulze; Christian Richter 📂 Article 📅 1991 🏛 John Wiley and Sons 🌐 English ⚖ 351 KB

The electron impact mass spectra of 2,4,5,5-tetrasubstitted 1,2,4triazolidine-3thiones exhibited, in addition to four main routes of fragmentation, a reaction leading to the formation of ~alkyl-l,2,Qtriazoline-3-thiows via an elimination of HR4 (R' < R4 are the substituents at C(5)) or via a McLaffe

Reactivity of unsaturated clusters. Phos
Reactivity of unsaturated clusters. Phosphoruscarbon bond activation, hydrogen migration and acetylene interconversion in the reactions of 46-electron (H)Ru3(CO)9(μ-PPh2) with Ph2PCCR (R = Ph, But, Pri). X-ray structure of Ru3(CO)9(μ-PPh2)2(μ3-η2-HCCPh): a new type of 5-vertex, 7-skeletal pair cluster
✍ Françoise Van Gastel; Shane A. MacLaughlin; Mike Lynch; Arthur J. Carty; Enrico 📂 Article 📅 1987 🏛 Elsevier Science 🌐 English ⚖ 448 KB
In the electron impact mass spectra of N
In the electron impact mass spectra of N,N′-diaryl-1,3-phenylenediamines, recorded under conditions generating the molecular ion as a base peak, the most important step involve a β-aromatic cleavage with H rearrangement, leading to the expulsion of a neutral arylamine; this fact can be used in meta isomer identification since for the corresponding 1,2- and 1,4-isomers the expulsion of an aryl radical is a competitive process
✍ Nicolae Palibroda; Castelia Cristea; Ioan A. Silberg; Ileana Chirtoc 📂 Article 📅 1999 🏛 John Wiley and Sons 🌐 English ⚖ 20 KB 👁 3 views