VAPOR-PRESSURES AND ENTHALPIES OF SUBLIMATION OF 4 POLYMETHOXYCARBONYLBENZENES

Vapour pressures of 1,3,5-trimethoxycarbonylbenzene, 1,3,5-C6H3(COOCH3 )(3); 1,2,4,5-tetramethoxycarbonylbenzene, 1,2,4,5-C6H2(COOCH3)(4); pe ntamethoxycarbonylbenzene, C6H(COOCH3)(5); and hexamethoxycarbonylbenz ene, C-6(COOCH3)(6), have been determined, over a 20 K temperature int erval, by the Knudsen-effusion technique. From the experimental result s of this work and our previously published thermochemical quantities, the standard molar enthalpies of sublimation, and formation in crysta lline and gaseous state at the temperature 298.15 K, have been derived .