Quantum chemical calculations of molecular energies in crystals of two polymorphs of m-nitrophenol with respect to ESR experiment
✍ Scribed by G. Wójcik; J. Lipiński; M. M. Szostak; M. Komorowska
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 299 KB
- Volume
- 6
- Category
- Article
- ISSN
- 1616-301X
No coin nor oath required. For personal study only.
✦ Synopsis
Energy differences between mnitrophenol (mNP) molecules in the gas phase and in two crystalline polymorphic forms-the optically non-linear orthorhombic and the centrosymmetric monoclinic formhave been found by the semiempirical all-valence modified INDO method. The calculations were performed for neutral molecules and for possible ions as well as for deprotonated molecules in the three phases. The values obtained for electron affinities, hyperpolarisabilities, electronic transition energies and spin densities on atoms in open-shell structures indicate that paramagnetic species are most favoured in the orthorhombic polymorph. This tendency corroborates our ESR results on the generation of unpaired spins by near-infrared excitation.