• Chitrani Medhi

Articles written in Journal of Chemical Sciences

• Theoretical studies on hydrogen bonding inπ-electron systems: A note on the structural features of diacetylene-hydrogen fluoride complexes

Ab initio supermolecular SCF calculations at the STO-3G level are reported for the diacetylene-hydrogen fluoride complexes. The reverse σ-complex is predicted to have somewhat higher stability and H-bond strength than the π-complexes.

• Macroscopic solvation of molecules in excited states: An MCSCF model including solvent polarization effects-I

An MCSCF model including the effects of solvent polarization is developed. The model is applied within the limitations of INDO approximations to look into the dominant effects of solvent polarization on the electronic structure in the excited states of a model system (e.g.* states of H2CO). Important features of macroscopic solvation-induced reorganization of electron density and some consequence thereof are noted.

• Basicity of some proto-typical carbonyls in the ground and some low lying excited states: Application of the orthogonal gradient method of orbital optimization in an INDO-MC-SCF framework-I

Gas phase proton affinities of formaldehyde and fluoroformaldehyde in the ground,1,3* (lowest) and3ππ* (lowest) states have been theoretically studied within the framework of the INDO-MC-SCF orthogonal gradient method developed earlier. Complete geometry optimization has been carried out for both the protonated and unprotonated bases in the ground and relevant excited states. Computed proton affinities (PA) of H2CO in different electronic states are in the following order:$$PA({}^1S_0 ) &gt; PA({}^3\pi \pi ^ * ) \sim PA({}^1n\pi ^ * ) &gt; PA({}^3n\pi ^ * )$$ In F2CO, however, the ordering turns out to be different viz PA(1S0)&gt;PA(1*)&gt;PA(3*)&gt;PA(3ππ*) for protonation at the carbonyl oxygen. For protonation at the F atom the ordering is PA(1S0)&gt;PA(3*)&gt;PA(1*)&gt;PA(3ππ*). Protonation at the oxygen atom is predicted to be energetically more favourable than protonation at one of the F atoms by approximately 30 kcal/mole in all the states studied. The role of Fermi correlation in shaping the difference in proton affinities of the singlet and triplet* states of H2CO is discussed.

• # Journal of Chemical Sciences

Volume 134, 2022
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019