RT info:eu-repo/semantics/article T1 π-Stacking isomerism in polycyclic aromatic hydrocarbons: The 2-Naphthalenethiol dimer A1 Saragi, Rizalina Tama A1 Calabrese, Camilla A1 Juanes San José, Marcos A1 Pinacho Gómez, Ruth A1 Rubio García, José Emiliano A1 Pérez Cuadrado, Cristobal A1 Lesarri Gómez, Alberto Eugenio K1 Aromatic compounds K1 Compuestos aromáticos K1 Chemical structure K1 Química K1 23 Química AB π-Stacking is a common descriptor for face-to-face attractive forces between aromatic hydrocarbons. However, the physical origin of this interaction remains debatable. Here we examined π-stacking in a model homodimer formed by two thiol-substituted naphthalene rings. Two isomers of the 2-naphthalenethiol dimer were discovered using rotational spectroscopy, sharing a parallel-displaced crossed orientation and absence of thiol–thiol hydrogen bonds. One of the isomers presents C2 symmetry, structurally analogous to the global minimum of the naphthalene dimer. The experimental data were rationalized with molecular orbital calculations, revealing a shallow potential energy surface. Noncovalent interactions are dominated by dispersion forces according to SAPT energy decomposition. In addition, the reduced electronic density shows a diffuse and extended region of inter-ring interactions, compatible with the description of π-stacking as a competition between dispersion and Pauli repulsion forces. PB American Chemical Society SN 1948-7185 YR 2022 FD 2022 LK https://uvadoc.uva.es/handle/10324/57927 UL https://uvadoc.uva.es/handle/10324/57927 LA eng NO The Journal of Physical Chemistry Letters, 2023, vol. 14, n. 1, p. 207–213 NO Producción Científica DS UVaDOC RD 03-jun-2024