In: Chemistry
Conformational analysis of a molecule was performed using a global-optimisation method where the energy was evaluated using Hartree-Fock (HF) theory. The binding energy of the low-energy conformers with a host complex was then calculated using the same level of theory. It was found that the lowest-energy conformer matched well with a known X-ray crystal structure but the binding energy with the host molecule was far too small.
(i) Define the term conformer.
(ii) Explain the general principles of global optimisation of a molecule and why global optimisation is challenging to perform.
(iii) Summarise the main contributions and terms that Hartree-Fock theory captures.
(iv)Explain why the low-energy conformers might be reasonably modelled by HF theory.