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Thermochemical properties of two benzimidazole derivatives: 2-Phenyl- and 2-benzylbenzimidazole

2005; Elsevier BV; Volume: 37; Issue: 11 Linguagem: Inglês

10.1016/j.jct.2005.02.008

1096-3626

Manuel A.V. Ribeiro da Silva, María D.M.C. Ribeiro da Silva, Luı́sa M.P.F. Amaral, José Elguero, Pilar Jiménez, Marı́a Victoria Roux, Juan Z. Dávalos, Manuel Temprado, Pilar Cabildo, Rosa M. Claramunt, Otília Mó, Manuel Yáñez,

thermodynamics and calorimetric analyses

The standard (p∘ = 0.1 MPa) molar enthalpy of formation for gaseous 2-phenylbenzimidazole (2-PhBIM) and 2-benzylbenzimidazole (2-BzBIM) were derived from the standard molar enthalpies of combustion, at T = 298.15 K, measured by static bomb calorimetry, and the standard molar enthalpy of sublimation, at T = 298.15 K, measured by Calvet microcalorimetry in the case of 2-phenylbenzimidazole or derived from the variation of the vapour pressures, determined by the Knudsen effusion technique, with temperatures between (393 and 412) K for 2-benzylbenzimidazole. Heat capacities, in the temperature ranges from (268.15 to 322.10) K for 2-phenylbenzimidazole and (270.15 to 316.02) K for 2-benzylbenzimidazole, were also measured with a differential scanning calorimeter. Empty CellΔcHm∘(cr)/kJ·mol-1ΔcrgHm∘(T=298.15K)/kJ·mol-12-Phenylbenzimidazole (2-PhBIM)−6679.8 ± 0.9123.0 ± 1.72-Benzylbenzimidazole (2-BzBIM)−7327.1 ± 4.0136.2 ± 0.5