Effect of phosphorus on the electronic and optical properties of naphthoxaphospholes: theoretical investigation

Density functional theory (DFT) and time-dependent DFT calculations were performed to elucidate the electronic and optical properties of 2-R-naphthol[2,3-d]xaphosphoies (R-NOP5). On the basis of the calculated results, the poor 7r overlap between the 3p(z) orbital of P atom and the 2p(z) orbitals of other atoms and increasing polarity of P atom result in a reduced energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital. When these two effects are considered simultaneously, the absorption energies obtained for the Si state can be below 3.00 eV according to replace the P atom of oxaphosphole ring by As atom (increasing the poor pi overlap) and change the functional groups (increasing polarity). The origin of these two effects is the inherent size of the 3p orbital of P atom. The role of P atom in the control of the electronic and optical properties of R-NOPs is clearly elucidated. [GRAPHICS] .