Structure-energy relationships in unsaturated esters of carboxylic acids. Thermochemical measurements and ab initio calculations.
Standard molar enthalpies of formation in the gaseous state of a series of alkyl 3-methylbut-2-enoates have been obtained from combustion calorimetry and results from the temperature dependence of the vapor pressure measured by the transpiration method. To verify the experimental data, we have performed ab initio calculations of all compounds. Enthalpies of formation derived from the G3MP2 method are in excellent agreement with the experimental results. Quantitative analysis of strain effects in alkyl 3-methylbut-2-enoates was discussed in terms of deviations of deltafH degrees m(g) from the group additivity rules. Energetics of the cis-trans isomerization of carboxylic acid derivatives was studied using G3MP2 and DFT methods. Values of strain and cis-trans corrections derived in this work provide further improvement on the group-contribution methodology for prediction of the thermodynamic properties of compounds relevant to biodiesel.
Emel'yanenko
Vladimir N
VN
Department of Physical Chemistry, University of Rostock, 18051 Rostock, Germany.
Toktonov
Alexey V
AV
Kozlova
Svetlana A
SA
Verevkin
Sergey P
SP
Andrushko
Vasyl
V
Andrushko
Natalia
N
Börner
Armin
A
D000085:Acetates / Q000737:chemistry; D002087:Butyrates / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D008956:Models, Chemical; D009574:Nitro Compounds / Q000737:chemistry; D011312:Pressure; D013237:Stereoisomerism; D013696:Temperature; D013816:Thermodynamics; D014835:Volatilization
C508635:6-(nitrooxy)hexyl-(2z)-4-(acetyloxy)-3-(4-(methylsulfonyl)phenyl)-2-phenylbut-2-enoate; D000085:Acetates; D002087:Butyrates; D002264:Carboxylic Acids; D004952:Esters; D009574:Nitro Compounds