@conference{
author = "Veljković, Dušan Ž. and Malinić, Miroslavka and Veljković, Ivana S. and Medaković, Vesna",
year = "2023",
abstract = "Pyramidane (tetracyclo[2.1.0.01,3.02,5]pentane, C5H4) and its derivates fall into the class of high-energy molecules with nonclasicall cage geometries [1]. Althoug pyrmidane itself has not been synthetized yet, cage molecules with strained triangular rings and an apex carbon atom were synthetized and their structures were determined. This provides an opportunity for the assessment of noncovalent bonding of the apex carbon atom in highly strained systems. Here, we analysed crystal stractures and performed interaction energies calculations to evaluate possibility of the apex carbon atom from pyramidane and pyramidane-like molecules to act as hydrogen atom acceptors in hydrogen bonds.
Analysis of crystal structures from Cambridge Structural Database (CSD) showed that there are short hydrogen-carbon contacts between apex carbon atom from pyramidane-like structures and hydrogen atoms from X-H fragments. Results of quantum chemical calculations performed on MP2/DEF2-TZVP level showed that pyramidane molecules and its derivatives can form strong hydrogen bonds involving apex carbon atom as hydrogen atom acceptor. Calculated energy of O-H•••C hydrogen bond between apex carbon atom of tetramethyl derivate of pyramidine and water was ΔE = -6.86 kcal/mol. This is significantly stronger than hydrogen bond between two water molecules (ΔE = 5.02 kcal/mol). Results of this study can by of greate importance for the recognition of nonclasical hydrogen bonds involving highly strained molecules. In addition, results presented here may help in the assessment of high-energy properties of strained cage molecules.",
publisher = "Belgrade : Serbian Crystallographic Society",
journal = "28th Conference of the Serbian Crystallographic Society, Čačak, Serbia, June 14–15, 2023",
title = "Strong hydrogen bonds involving carbon atom as hydrogen atom acceptor",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6291"
}