Insights into Unconventional Intramolecular CH center dot center dot center dot CO Interaction in Os-3(CO)(9)(mu-H)(2)(mu(3)-eta(1): eta(1): eta(2)-C16H8) Crystal: A QTAIM, NCI, and NBO Exploration

This work presents a study investigating the inter- and intramolecular interactions within the Os-3(CO)(9)(mu-H)(2)(mu(3)-eta(1): eta(1): eta(2)-C16H8) crystal. The crystal's behavior is analyzed by comparing experimental distances, revealing intriguing interactions. In the isolated molecule, an unconventional pyrene-C-H center dot center dot center dot CO interaction is observed, an electron transfer from s(C-H) to pi*(CO). Strikingly, the Quantum Theory of Atoms in Molecules identifies similarities to an intramolecular charge-inverted hydrogen bond, despite its relatively low stability due to proximity to critical points. Energy surface scans demonstrate that the interaction arises from van der Waals strain induced by the crystal's packing structure. The proximity between carbonyl and pyrene facilitates electron transfer between sigma(C-H) and pi*(CO) at distances similar to the crystal structure. A significant correlation is established between total energy and the ratio ( j V | /G) of potential energy density (V) to Lagrangian kinetic energy (G) at bond (BCP) and ring (RCP) critical points, underscoring the role of electron delocalization on the pseudo-ring in determining the existence and characteristics of these interactions. In conclusion, this study provides valuable insights into molecular interactions within the Os-3(CO)(9)(mu-H)(2)(mu(3)-eta(1): eta(1): eta(2)-C16H8) crystal, enriching our understanding of crystal interactions and offering perspectives for further exploration in this field.