Raman spectroscopy study of phosphorus-containing dendrimers built from thiophosphoryl core

Abstract

The FT-Raman spectra of 10 generations of phosphorus-containing dendrimers containing P=S and P=O bonds with terminal benzaldehyde and P-Cl groups have been recorded and analyzed. The Raman spectra of dendrimers are determined by the ratio T(n)/R(n) (T(n)--number of terminal groups, R(n)--number of repeating units). This ratio trends to r-1 (r--branching functionality of repeating unit), and becomes constant, when the generation number is higher than 3. The lines full width at half height in Raman spectra of 10 generations was measured. The possibility appears to separate the lines assigned to the core, repeating units and terminal groups of dendrimers by difference spectroscopy method. The influence of the encirclement on the line frequencies and intensities was studied and due to the predictable, controlled and reproducible structure of dendrimers the information, usually inaccessible is obtained. Some lines in the Raman difference spectra have characteristic EPR-like form. The strong line at 1600 cm(-1) show marked changes of intensity in dependence of aldehyde (-CH=O) or azomethyne (-CH=N) substituents in the aromatic ring.