Experimental and Computational Study on the Thermochemistry of Bromoanilines

Abstract

Abstract The standard (p° = 0.1 MPa) molar enthalpies of formation of 2-, 3-, and 4-bromoaniline, 2,4-, 2,5-, and 2,6-dibromoaniline, and 2,4,6-tribromoaniline were derived from the standard molar enthalpies of combustion, in oxygen, which yields CO2(g), N2(g), and HBr·600H2O(l), at T = 298.15 K, measured by using rotating-bomb calorimetry. The standard molar enthalpies of sublimation, or vaporization, of these compounds at T = 298.15 K were measured by using Calvet microcalorimetry, and so their standard molar enthalpies of formation in the gaseous state were derived. The enthalpies of fusion of the solid compounds were determined by DSC. The gas-phase enthalpies of formation were also estimated by density functional theory calculations performed at the BP86/6-31+G* level. As a result it is confirmed that thermodynamic data is consistent with intramolecular N–H···Br hydrogen bonding.