DFT study of Raman spectra of phosphorus-containing dendrons built from cyclotriphosphazene core

Abstract

The FT-Raman spectra of the zero and first generations of phosphorus-containing dendrons with terminal oxybenzaldehyde and PCl groups and one ester function have been recorded and analyzed. The structural optimization and normal mode analysis were performed for dendrons on the basis of the density functional theory (DFT). The calculated geometrical parameters, harmonic vibrational frequencies and Raman scattering activities are predicted in a good agreement with the experimental data. The experimental Raman spectra of dendrons were interpreted by means of potential energy distribution. Relying on DFT calculations the lines of the core, repeating units and terminal groups of dendrons were assigned.The influence of the encirclement on the line frequencies and intensities was studied and due to the predictable, controlled and reproducible structure of dendrons the information, usually inaccessible is obtained. The polarizabilities and lipophilicity of dendrons were estimated. The strong line at 1600cm−1 show marked changes of intensity in dependence of aldehyde (СНО), ester (OСO) or azomethyne (СНN) substituents in the aromatic ring.