I have optimised the geometry of the dimer of a molecule using pcm solvent model and B3LYP functional with 6311++G(d,p) basis set in Gaussian 09 software. There is possibility of C-H...O H bonding as seen from the H...O distance but NBO analysis shows very small values of E(2) for any two donor and acceptor orbitals between the two units. The binding energy of the dimer is 7.4 kcal/mol. Also, there is possibility of dipole-dipole interaction between two carbonyl groups of two units but I do not know how to study that interaction strength. How can I check what is the stabilising factor here, if not H bonding?
You could have Gaussian calculate the absolute dipole moment of your monomer molecules; then you check your optimized geometry how those dipoles then would stand and apply the general formula for dipole-dipole interaction:
https://web.chem.ox.ac.uk/teaching/Physics%20for%20CHemists/Electricity/Dipoles.html
(the last formula at the bottom)
Then you should receive an energy which you can subtract from your binding energy; the remainder is the binding part that's not from dipole force.
- Badges
- Science topic
- Similar topics
- Computer Communications (Networks)
- Simulators