Vapor pressures and vaporization enthalpies of a series of esters used in flavors by correlation gas chromatography

• The vaporization enthalpies of a series of esters used in flavoring.
• Vapor pressures are also reported and compared to existing data.
• Equations are reported covering vapor pressures from T = 298.15 K to each compound’s respective normal boiling temperature.

The vaporization enthalpies of a series of esters used commercially as flavor ingredients are reported as are their vapor pressures over the temperature range T/K = (298.15 to TB). Vaporization enthalpies and vapor pressures at T = 298.15 K (ΔlgHm(298.15)/kJ ⋅ mol−1, p/Pa) for 3-methyl-2-butenyl acetate (47.8 ± 1.5, 468 ± 7.2), trans trans 2,4-hexadienyl acetate (54.7 ± 1.4, 89 ± 1.5), ethyl 2-methylpentanoate (48.4 ± 1.5, 410 ± 42), cis 3-hexenyl propionate (55.7 ± 1.0, 66.2 ± 3), allyl hexanoate (55.2 ± 1.6, 81.9 ± 10), pentyl butyrate (53.6 ± 0.6, 109 ± 1.1), isoamyl isobutyrate (51.7 ± 1.6, 180 ± 20), phenethyl acetate (61.3 ± 1.3, 13.2 ± 0.2), cis-3-hexenyl butyrate (59.9 ± 1.7, 25.7 ± 2.2), cis 3-hexenyl 2-methylbutyrate (61.5 ± 0.6, 15.3 ± 1), ethyl cinnamate (70.4 ± 1.4, 1.5 ± 0.03), phenethyl propionate (65.6 ± 1.6, 4.8 ± 0.09), cis-5-octenyl propionate (65.3 ± 1.6, 7.0 ± 0.1), heptyl butyrate (65.1 ± 1.1, 7.8 ± 0.05), phenethyl butyrate (69.7 ± 1.4, 1.9 ± 0.4), linalyl acetate (62.5 ± 0.6, 12.2 ± 0.2), citronellyl acetate (67.8 ± 1.8, 4.0 ± 0.4), and phenethyl hexanoate (78.8 ± 1.5, 0.23 ± 0.005) have been evaluated by correlation gas chromatography experiments. The vaporization enthalpies of the esters studied are reproduced within ±2.0 kJ ⋅ mol−1 using a simple additivity scheme. Constants for a third order polynomial are reported which reproduces vapor pressures and predicts normal boiling temperatures to within T = 3.0 K.

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