Thermodynamic Study of Three Phenanthroline Derivatives

In the context of an ongoing study on the thermodynamic characterization of nitrogen heterocyclic compounds, this communication is concerned with the experimental thermophysical and thermochemical studies that have been recently developed on three phenanthroline derivatives – neocuproine, bathophenanthroline and bathocuproine (figure 1)[1,2]. These compounds exhibit properties that make them relevant ligands in coordination chemistry and potential candidates for their use as charge carrier transporting materials in organic semiconductor devices [3] The thermal behaviour of the two compounds has been studied using differential scanning calorimetry and thermogravimetric analysis. In order to determine the respective standard molar enthalpies of sublimation, measurements were carried out using Knudsen effusion mass loss/mass spectrometry, a quartz crystal microbalance technique and high-temperature vacuum drop-microcalorimetry. Static bomb combustion calorimetry has been used to determine the standard molar enthalpy of formation in the crystalline phase. From these values, it has been possible to derive the standard molar enthalpy of formation of the given compounds for the gaseous and liquid phases. The results obtained provide a deeper understanding of the phase transition behaviour for these compounds from condensed phases to the gaseous phase, shedding light on molecular decomposition and both intra and intermolecular forces inherent to the species. This knowledge contributes to the comprehensive characterization of the thermodynamic properties of these nitrogen heterocyclic compounds. Keywords: Phenanthroline Derivatives; Phase Transitions; Thermophysical Study; Thermochemical Properties; Calorimetric Study. References [1] J.M. Silva Ferraz. et al. Thermodynamic Study of Neocuproine, IJUP 2022, Porto, Portugal (Book of Abstracts, Chemistry IV Session, Oral Communication) [2] J.M. Silva Ferraz et al. Thermophysical Analysis of Phenanthroline Derivatives, MEDICTA 2023, Porto, Portugal (Book of Abstracts, Section F, Oral Communication) [3] Farinhas, J.; Ferraria, A. M.; do Rego, A. M. B.; Morgado, J.; Charas, A. Chemistry Select 2016, 1 (18), 5638-5646.