Experimental thermochemical study of 2,5- and 2,6-dichloro-4-nitroanilines

Experimental thermochemical study of 4,5-dichloro-2-nitroaniline

“…Cox assumed that each group in the benzene ring produces a characteristic enthalpic increment in the enthalpy of formation in the gaseous phase, being necessary to consider a correction term of 4 kJ Á mol À1 for each ortho pair of substituents and another additional correction term of 4 kJ Á mol À1 for every set of three substituents in three consecutive carbon atoms of the benzenic ring. In previous works, it was suggested [12] and later verified [40] the necessity of an additional correction term of 22 kJ Á mol À1 , whenever the ortho pair of substituents are the chlorine atom and the nitro group, and it was also concluded [13], that the two correction terms suggested by Cox [39] should not be used when the chlorine atom and the amino group are in ortho positions due to the formation of an intramolecular bond as previously experimentally observed [6,7]; these two corrections were taken in account on the estimations made in this work.…”

“…from data of Domalski and Hearing [35] and using the following group additivity approach: 2 , cr] = 33.55 J Á K À1 Á mol À1 and due to the absence of the C p;m [C B -(NO 2 )(C B ) 2 , g] parameter in the Domalski and Hearing group additivity method [35] was used the value of 53.69 J Á K À1 Á mol À1 , estimated in a previous work [13], was used.…”

“…The present work is a contribution to the thermochemical investigation of halogenated anilines and nitroanilines carried out by the Molecular Energetics Research Group of the University of Porto, from which the fluoroanilines [3,4], chloroanilines [5][6][7][8], bromoanilines [9], iodoanilines [10], monochloronitroanilines [11,12], and two dichloro-4-nitroaniline isomers [13] have already been studied. This paper reports the standard ðp ¼ 0:1 MPaÞ molar enthalpy of formation, of 4,5-dichloro-2-nitroaniline, in the crystalline phase, at T = 298.15 K, derived from the standard massic energy of combustion, in oxygen, at the same temperature, measured by rotating-bomb combustion calorimetry.…”

Experimental thermochemical study of two chlorodinitroaniline isomers

“…and due to the absence of the value of C p;m ½C B -ðNO 2 ÞðC B Þ 2 ; g parameter in the Domalski and Hearing reported data [9] the value of 53.69 J Á K À1 Á mol À1 , as estimated in a previous work [3], was used.…”

“…This work is part of a systematic investigation of the thermochemical properties of chlorinated nitroanilines [1][2][3][4] carried out by the Molecular Energetics, Colloids and Bio-interfaces Research Group of the University of Porto.…”