Kinetic and Theoretical Study of the Effect of Molecular Sieve Structure on the Selectivity to Propylbenzenes in Alkylation of Benzene with Isopropyl Alcohol

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Title:Kinetic and Theoretical Study of the Effect of Molecular Sieve Structure on the Selectivity to Propylbenzenes in Alkylation of Benzene with Isopropyl Alcohol
Creators:
Čejka, Jiří
Žilková, Naděžda
Šponer, Judit E.
Wichterlová, Blanka
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 63, 11, pp. 1769-1780
Uncontrolled Keywords:anti-Markovnikov rule, <i>Ab initio</i> calculation, Molecular sieves, n-Propylbenzene formation, Alkylation of benzene, Heterogeneous catalysis, Zeolites, Isopropyl alcohol

Abstract

The alkylation of benzene with isopropyl alcohol was investigated over molecular sieves of different structural types and acidity by kinetic measurements and <i>ab initio</i> quantum chemical calculations. The formation of n-propylbenzene occurring <i>via</i> bimolecular transalkylation between isopropylbenzene and benzene is enhanced by the appropriate geometry of the reaction space and the acidity of molecular sieves. n-Propylbenzene was formed over medium and large pore molecular sieves with such inner channel architecture which enables the approach of isopropylbenzene and benzene to form the reaction complex. Mesoporous sieves of MCM-41 structure provided only isopropylbenzene with some amount of diisopropylbenzenes. For the fully relaxed complex consisting of protonated isopropylbenzene and benzene, the computations verified the transfer of propyl group from one benzene molecule to another forming again isopropylbenzene. When the geometrical conditions modelling the channel intersections of ZSM-5 and ZSM-11 structures were considered n-propylbenzene was formed. The anti-Markovnikov type of proton transfer from the arenium cation to the propene part of the complex is promoted by the steric constraints present in the channel intersections of ZSM-5 and ZSM-11 zeolites.

Title:Kinetic and Theoretical Study of the Effect of Molecular Sieve Structure on the Selectivity to Propylbenzenes in Alkylation of Benzene with Isopropyl Alcohol
Creators:
Čejka, Jiří
Žilková, Naděžda
Šponer, Judit E.
Wichterlová, Blanka
Uncontrolled Keywords:anti-Markovnikov rule, <i>Ab initio</i> calculation, Molecular sieves, n-Propylbenzene formation, Alkylation of benzene, Heterogeneous catalysis, Zeolites, Isopropyl alcohol
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:63
Number:11
Page Range:pp. 1769-1780
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19981769UNSPECIFIED
ID Code:1419
Item Type:Article
Deposited On:06 Feb 2009 17:09
Last Modified:06 Feb 2009 16:09

Citation

Čejka, Jiří; Žilková, Naděžda; Šponer, Judit E.; Wichterlová, Blanka (1998) Kinetic and Theoretical Study of the Effect of Molecular Sieve Structure on the Selectivity to Propylbenzenes in Alkylation of Benzene with Isopropyl Alcohol. Collection of Czechoslovak Chemical Communications, 63 (11). pp. 1769-1780. ISSN 0010-0765

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