“…A literature survey showed the scarcity of thermodynamic data for heteropolycyclic compounds that motivated our involvement in a systematic study of compounds structurally formed by two benzene rings fused to a pentagonal or hexagonal central ring, containing oxygen, sulfur or nitrogen as heteroatoms [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. This work has been developed in a “duo dynamic” between the experimental and computational studies of those species, with the main goal of determining their thermodynamic properties, among others.…”