Shimaa Hussien - Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, ۱۱۷۱۱, Cairo, Egypt.
Tarik Elsayaed Ali - Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, ۱۱۷۱۱, Cairo, Egypt.

Geometry, global energetic and dipole moment of the studied structures ۱-۴ in the ground state are calculated using the DFT/B۳LYB/۶-۳۱۱++G (d,p) level of theory.  It has been uncovered that compounds containing ۱, ۲, ۳-thiazaphosphinine and ۱, ۲-azaphospholes bearing a Chromone ring structure displays noteworthy biological properties. The studied compounds ۱-۴ are non-planar, as indicated from the dihedral angles. Using frontier molecular orbital (FMO) analysis, various spectroscopic and quantum chemical parameters are evaluated. Besides, absorption energies, oscillator strength, and electronic transitions of ۱, ۲, ۳-thiazaphosphinine and ۱, ۲-azaphospholes ۱-۴ molecules have been derived at TD-DFT/CAM-B۳LYP/۶-۳۱۱++G (d, p) computations utilizing a PCM and measured in different solvents polar and non-polar experimentally in Uv-Vis spectra. The second-order perturbation interactions between donor and acceptor MOs of the ground state and the natural bond orbital (NBO) analysis show a localization and delocalization of electron density, intermolecular Charge Transfer CT character of n-π*, π-π* transitions. The calculated at the same level of theory which NLO, α, Δα and first order β were showed promising optical properties. For the understanding of reactivity points, the molecular electrostatic potential surfaces (MEPS) plots have been computed. All the calculations have been performed in the gas phase.

DFT/TD-DFT/ B۳LYB/۶-۳۱۱++G (d, p), MEPS, NLO and NBO analysis, Optoelectronic Application, Uv-Vis Spectra, ۲, ۳-Thiazaphosphinine, ۱, ۲-Azaphospholes