Cyclodimerisation and cyclotrimerisation during the ring-opening reactionsof ethylene sulfide (thiirane) over acidic molecular sieves and alumina

Citation
A. Fasi et al., Cyclodimerisation and cyclotrimerisation during the ring-opening reactionsof ethylene sulfide (thiirane) over acidic molecular sieves and alumina, CATAL LETT, 76(1-2), 2001, pp. 95-98
Citations number
9
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics","Chemical Engineering
Journal title
CATALYSIS LETTERS
ISSN journal
1011-372X → ACNP
Volume
76
Issue
1-2
Year of publication
2001
Pages
95 - 98
Database
ISI
SICI code
1011-372X(2001)76:1-2<95:CACDTR>2.0.ZU;2-Q
Abstract
The transformations of ethylene sulfide were studied at three reaction temp eratures (423, 473 and 523 K) on different acidic molecular sieves (HZSM-5, HY and AlMCM-41) and alumina in a pulse system. The main reaction pathways were found to be desulfurisation, cyclo-oligomerisation, the latter being more important. In this reaction channel mainly direct dimer (six-membered ring: 1,4-dithiane) and trimer (1,4,7-trithiacyclononane) formation occurre d. The former product was always predominant, however, 1,4,7-trithiacyclono nane was also significant, especially on molecular sieves with larger pore openings and alumina. At elevated temperatures 2-methyl-1,3-dithiolane (a f ive-membered cyclic molecule) was also detected. This molecule was formed i n the highest amount on HZSM-5 among the catalysts applied revealing that a more constrained environment is advantageous for this dimerisation type to occur.