(Solid + liquid) equilibria, i.r., and semi-empirical studies of carbazole with selected tertiary amides

• Published in: The Journal of chemical thermodynamics 2001-05, Vol.33 (5), p.565-579
• Main Authors: Jamróz, Małgorzata E., Dobrowolski, Jan Cz, Polaczek, Jerzy, Szafrański, Andrzej M., Kazimirski, Jan K., Lisicki, Zygmunt
• Format: Article
• Language: English
• Subjects: amides; carbazole; Chemistry; Exact sciences and technology; General and physical chemistry; hydrogen bond; i.r; Liquid-solid equilibria; Phase equilibria; semi-empirical; solid + liquid
• ISSN: 0021-9614; 1096-3626
• DOI: 10.1006/jcht.2000.0770

(Carbazole +tert -amide) systems were investigated through measurement of (solid + liquid) equilibria (s.l.e.), i.r. study, and semi-empirical calculations. The s.l.e. studies included three systems, namely (carbazole + tetramethylurea, orN , N - diphenylacetamide, or N -acetylcarbazole). In spite of the identical tertiary N-atom, andC=O group occurring in each studied amide assumed to dominate molecular interactions, the liquidus curves have revealed the presence of a hydrogen-bond complex only in the first system. The remaining two are simple eutectic systems, probably owing to sterical hindrance exhibited by large substituents. Each system, as well as (carbazole +N, N - dimethylformamide) were studied using i.r. spectroscopy in 1,1,2,2-tetrachloroethene solutions. In contrast to s.l.e. data, hydrogen-bond formation manifested itself in each system studied by the i.r. method. The enthalpy of complex formation was determined from the spectroscopic data for each system except for (carbazole +N -acetylcarbazole). The i.r. studies were supported by semi-empirical calculations performed for the optimized hydrogen-bond geometries.