Theoretical investigation of intramolecular π-type hydrogen bonding and internal rotation of 2-cyclopropen-1-ol, 2-cyclopropen-1-thiol and 2-cyclopropen-1-amine
Abstract
Theoretical computations utilising both CCSD and MP2 methods and the cc-pVTZ basis set have been carried out to determine the structures of several conformations as well as the internal rotation potential energy functions for 2-cyclopropen-1-ol, 2-cyclopropen-1-thiol and 2-cyclopropen-1-amine. The energies and wavefunctions for these potential functions have also been computed. Each of these molecules has an energy minimum corresponding to a conformation with intramolecular π-type hydrogen bonding. The π bonding stabilisation is about 2.3 kcal/mole for the alcohol, 2.1 kcal/mole for the thiol, and about 2.5 kcal/mole for the amine. The results for the thiol demonstrate a rare example of intramolecular π-type hydrogen bonding. The calculated O-H, S-H, N-H, and C=C stretching frequencies have also been compared for the conformations with and without the π-type hydrogen bonding. The C=C stretching frequency is substantially lower in all cases for the hydrogen bonded conformers.
- Publication:
-
Molecular Physics
- Pub Date:
- June 2019
- DOI:
- 10.1080/00268976.2018.1554192
- Bibcode:
- 2019MolPh.117.1404O
- Keywords:
-
- π-type hydrogen bonding;
- internal rotation;
- 2-cyclopropen-1-ol;
- 2-cyclopropen-1-thiol;
- 2-cyclopropen1-amine