کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5418999 | 1506979 | 2006 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Gas-phase enthalpies of formation of the fluorobenzenes family and their dewar isomers from ab initio calculations Gas-phase enthalpies of formation of the fluorobenzenes family and their dewar isomers from ab initio calculations](/preview/png/5418999.png)
The standard gas-phase enthalpies of formation, at T = 298.15 K, of the complete series of fluorobenzene and their corresponding dewar isomers have been determined by means of the CBS-QB3 and G3MP2B3 composite approaches. These values have been estimated by using appropriate supporting reactions, such as, reactions of atomization or of atom substitution. The results show that there is a linear dependence between the enthalpy of the most stable n-fluorobenzene and the corresponding n-fluorodewar benzene (n = 0, 1, â¦, 6). Further, the estimates are always more negative than the experimental results and so, suggested enthalpies of formation for 1,2,3-, 1,2,4- and 1,3,5-trifluorobenzenes and for 1,2,3,4- and 1,2,3,5-tetrafluorobenzenes are those retrieved from G3MP2B3 calculations added by 8 kJ/mol. The interaction of four different M+ ions with fluorobenzene and the three difluorobenzenes shows that the Ï-interaction with 1,2-difluorobenzene is stronger than Ï-interaction on these fluorobenzenes.
Journal: Journal of Molecular Structure: THEOCHEM - Volume 778, Issues 1â3, 11 December 2006, Pages 77-84