Unravelling the importance of hydrogen bonds and dihydrogen interactions in the supramolecular assembly of a caryolan-1-ol derivative: an experimental and theoretical investigation

We report here the synthesis of a caryolan-1-ol derivative, namely [(1R, 2S, 5R, 8S)-1-hydroxy-4,4,8-trimethyltricyclo[6.3.1.02,5]dodecan-6-one] (3), characterized by structural single-crystal X-ray diffraction, FTIR and 1H and 13C NMR spectroscopies. The crystal structure reveals weak noncovalent interactions along with O-H center dot center dot center dot O hydrogen bonding interactions that forms 1D network architectures. Hirshfeld surfaces and their twodimensional fingerprint plots allow us to visualize the intermolecular contacts and their relative contributions to the total Hirshfeld surface for the compound. A comparative analysis against related compounds was carried out. The interaction energies for the molecular pair involving O-H center dot center dot center dot O hydrogen bonds indicated a dominant contribution to packing stabilization coming from the Coulombic components. Energy framework calculations afforded to analyse and visualize the topology of the intermolecular interactions responsible for the crystal packing, showing that dispersion energy prevail over the electrostatic one in the structure of 3. Theoretical calculations have been performed to analyse the unconventional noncovalent interactions observed in the solidstate structure of 3 using the quantum theory of atoms in molecules (QTAIM), noncovalent interactions plot (NCIplot) and natural bond orbital (NBO) computational tools.