Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The vaporization enthalpies at T/K = 298.15 and vapor pressures from T/K = (298.15 to Tnb (normal boiling temperature)) of muscalure (Z-9-tricosene) and empenthrin [(E)-(RS)-1-ethynyl-2-methylpent-2-enyl (1RS)-cis-trans-2,2-dimethyl-3-(2-methylprop-1-enyl)-cyclopropane-carboxylate], have been evaluated by correlation gas chromatography. Commercial samples of muscalure also contain a small amount of E-9-tricosene. Vaporization enthalpies of [(114.4 +- 1.0) and (114.5 +- 1.0)] kJ*mol 1 and vapor pressures, p/Pa = [(1.2 +- 0.1) and (1.1 +- 0.1)]*10 4, both at T/K = 298.15 have been evaluated for Z and E-9-tricosene, respectively. Empenthrin is also a mixture of possibly four diasteriomers. Two of the diasteriomers, empenthrin 1 and 2, are separated by the chromatography and are characterized by the order of their elusion off the column. Vaporization enthalpies of [(87.2 +- 4.8) and (87.0 +- 4.8)] kJ*mol 1 and vapor pressures, p/Pa = [(594 +- 380) and (601 +- 383)]*10 4, also at T/K = 298.15 have been evaluated for the two diasteriomers, empenthrin 1 and 2, respectively. Vapor pressure equations generated by correlation for muscalure predict a boiling temperature at p/Pa = 133 of Tb/K = 449 (lit. 453) and for empenthrin 1 and 2 at p/Pa = 101325 of Tnb/K = 567.9 and 569.2 (lit. 568.7). The vapor pressure values for empenthrin at T/K = 298.15 serve as a test case for comparing the accuracy of vapor pressure measurements using other GC retention time methods on environmentally sensitive materials.