OICC Press Journal of Nanostructure in Chemistry 2193-8865 12 6 (December 2022) 2022 05 21 Analysis of the host–guest complex formation involving bridged hexameric pyridinium–phenyl rings in the HexaCage6+ host in suit[3]ane: insights from dispersion-corrected DFT calculations for a nanometric mechanically interlocked device 10.1007/s40097-022-00497-y EN Renato L. T. Parreira Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, Franca, SP, BR Giovanni F. Caramori Department of Chemistry, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, BR Letícia Maria Pequeno Madureira Department of Chemistry, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, BR Raul Guajardo-Maturana Facultad de Ciencias de la Salud, Instituto de Investigación Interdisciplinar en Ciencias Biomédicas SEK (I3CBSEK) Chile, Universidad SEK, Providencia, Santiago, CL Peter. L. Rodríguez-Kessler Laboratorio de Química Inorgánica y Materiales Moleculares, Facultad de Ingeniería, Universidad Autonoma de Chile, San Miguel, Santiago, CL Alvaro Muñoz-Castro Laboratorio de Química Inorgánica y Materiales Moleculares, Facultad de Ingeniería, Universidad Autonoma de Chile, San Miguel, Santiago, CL Journal Article 2022 05 21 Abstract Efficient and affordable synthetic nanometric hosts able to incorporate different species have attracted attention for further exploration of changes in chemical properties and reactivity at the nanomolecular scale. The recent incorporation of suit[3]ane, involving a host composed by two parallel hexameric platforms alternating pyridinium and phenyl rings, bridged by three p -phenylene units (Hexacage +6 ), results in a mechanically interlocked nanometric host–guest pairs. In such species, the host structure follows the contour of the guest, extends the well-developed use of charged pyridinium-based structures to Hexacage +6 , and the use of benzotrithiophene (BTT) and its alkylated derivative (THBTT). Our results show a sizable stabilization of -119.0 kcal mol −1 , in the formation of the host–guest complex, with a relevant London dispersion character contributing by ~ 60% of the stabilizing factors. This result accounts for the extended and π⋯π and C–H⋯π surface given by the BTT-aromatic core and the hexyl chains, respectively, towards the HexaCage 6+ moiety in suit[3]ane. In addition, polarization and electrostatic character also contribute to the stabilization of the host–guest complex. The removal of the alkyl chains of THBTT leads to BTT, for which the interaction energy with the HexaCage 6+ , decreases to − 49.1 kcal mol −1 , denoting the enhanced stabilization introduced by the alkyl moieties. The origin of the observed shielding patterns from 1 H-NMR experiments was also revisited. Lastly, the understanding of the role from different stabilizing terms is useful for further rationalization and design of selective and enhanced hosts towards more versatile and tunable hosts. Charge transfer integrals in the host–guest species (THBTT⊂HexaCage 6+ and BTT⊂HexaCage 6+ ) were directly evaluated as the matrix elements of Kohn–Sham Hamiltonian, defined in terms of molecular orbitals of individual host and guest molecules. Our findings are totally in line with EDA results indicating that electron transfer is not the most significant process to the host–guest stabilization. Graphical abstract Fundamental analysis of mechanically interlocked structures at the nanomolecular scale, allows envisaging further nanometric molecular machines. Explanation of the Abstract graphics: Since the formation of the host–guest structure leads to a mechanically interlocked device, a shocking picture with stunning colors, denoting inclusion and motion was selected for the art.