Computational study of physicochemical, optical, and thermodynamic properties of 2,2-dimethylchromene derivatives

A large number of heterocyclic compounds are used as drugs, mainly due to the duality of lipophilicity playing in hydrophobic interactions and solubility with at least one hydrogen bond acceptor. The study of electronic properties is then important to better understand not only these charge distribution effects but also some other physicochemical properties involved in bioactivity to directly assess the bioavailability of these compounds and a possible classification in related applications. Phytomolecules such as chromenes are very accessible molecules exhibiting a bioactivity. Our study is focused on the impact of a number of functional groups acting on some 2,2-dimethylchromene derivatives, namely their global reactivity from the frontier molecular orbitals and local reactivity from the Fukui functions, where the carbonyl group acting as an electron withdrawal group has the most relevant effect, the solubility from the partition coefficient Log P strongly depending on the charge distribution and electronegative sites, the optical effects from the delocalization in the vinyl group, as well as the evaluation of the entropy associated with the molecular flexibility also acting on the bioactivity. Despite the effects of the wave function or density methods on the order of magnitude of these properties, these compounds are consistent with the rules for a potential oral drug candidate.

The calculations of the electronic properties were performed through two levels of theory: Hartree-Fock level as a wave function-based method as an ab initio reference including some physically consistent eigenvalues and density functional theory DFT as a correlation consistent method using different functionals: hybrid or with a long-range correction. The basis set used is a 6-311++G(d,p) Pople basis set including diffuse and polarization basis functions. The basis set is adapted to the size of the molecules and consequently to the degree of electronic localization. Gaussian 09 software was used for the computation.