20.500.12556/RUL-166768 Impact of molecular and crystal structure on the melting points in halo-substituted phenyl-quinazolinones Three halo-substituted phenyl-quinazolinone derivatives were prepared and structurally characterized [1 = 3-(4-chlorophenyl)-6-iodo-2-methylquinazolin-4(3H)-one, 2 = 6-iodo-3-(4-methoxyphenyl)-2-methylquinazolin-4(3H)-one, and 3 = 7-chloro-2-methyl-3-[4-(trifluoromethoxy)phenyl]quinazolin-4(3H)-one)] in order to explore the relationship between structure and melting point in this group of compounds. Depending on the compound, molecules are interconnected by weak π∙∙∙π interactions, have I···Cl or Cl···Cl halogen bonding, or primarily form C–H∙∙∙N, C–H∙∙∙O, and π∙∙∙π interactions (no halogen bonding). The presence of the OCF$_3$ group leads to interactions between fluorine atoms that are shorter than the sum of the van der Waals radius for fluorine, suggesting that these interactions contribute to the overall lattice energy. The sequence of melting points cannot be fully explained by intermolecular interactions present in the solid state (enthalpy factor). To address this, a concept related to entropy called the functional group rotation influence, which relates to a decrease in fusion entropy caused by the rotational freedom of polyatomic groups, was introduced. Analysis of previously synthesized 3-phenylquinazolinones showed that the compounds with the highest melting point are the quinazoline-substituted and phenyl-nitro-substituted ones. Among halo-phenyl-substituted compounds, the melting point follows the sequence ortho < meta < para. Regarding the halogen atom type, the order of melting points is Cl ≈ Br > F > I for enantiopure and Br > I ≈ Cl > F for racemic compounds. Also, the melting point order correlates to halogen bond energy (I > Br > Cl > F) only when the geometry and energy of these interactions are favorable. phenyl-quinazolinones halogen bond interactions melting point functional group rotation influence fenil-kinazolinoni halogenske vezi tališče vpliv rotacije funkcionalne skupine true false true Angleški jezik Slovenski jezik Članek v reviji 2025-01-24 09:54:00 2025-01-24 09:54:01 2025-01-25 04:13:10 0000-00-00 00:00:00 2025 0 0 19 str. iss. 1, art. 39 Vol. 15 Jan. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.1:547.856 2073-4352 10.3390/cryst15010039 221536003 RAZ_Dilovic_Ivica_2025.pdf RAZ_Dilovic_Ivica_2025.pdf 1 C458605F167B733EBF9E36073449C8D9 c7d17408065df69e642e4c91951cae2f54ffbefc5b61186d750dbf4492869dcb 2c3a4dda-da31-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=198642 https://www.mdpi.com/2073-4352/15/1/39 1 f5f7babc-da2f-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=198641 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0