title: Substituent effects on the thermochemistry of thiophenes. a theoretical (G3(MP2)//B3LYP and G3) study.
abstract: Very good linear correlations between experimental and calculated enthalpies of formation in the gas phase (G3(MP2)//B3LYP and G3) for 48 thiophene derivatives have been obtained. These correlations permit a correction of the calculated enthalpies of formation in order to estimate more reliable "experimental" values for the enthalpies of formation of substituted thiophenes, check the reliability of experimental measurements, and also predict the enthalpies of formation of new thiophenes that are not available in the literature. Moreover, the difference between the enthalpies of formation of isomeric thiophenes with the same substituent in positions 2 and 3 of the ring has been analyzed. Likewise, a comparison of the substituent effect in the thiophene and benzene rings has been established.
authors.affiliation: Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain. rnotario@iqfr.csic.es
authors.forename: Rafael
authors.initials: R
authors.lastname: Notario
authors.forename: Manuel
authors.initials: M
authors.lastname: Temprado
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Roux
authors.forename: Joel F
authors.initials: JF
authors.lastname: Liebman
mesh_terms: D015394:Molecular Structure; D011789:Quantum Theory; D013696:Temperature; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D013876:Thiophenes