STRUCTURAL CHARACTERIZATION OF POLYBENZYLS BY HIGH FIELD ¹³C-NMR SPECTROSCOPY.

**1**3C-NMR Spectroscopy has been used for the structural characterization of polybenzyls synthesized from the polymerization of benzyl chloride catalyzed by arene chromium tricarbonyls. The **1**3C-chemical shifts for various mono-, di-, tri-, and tetrasubstituted phenyl groups in a polybenzyl have been calculated by the use of additivity parameters and compared with their observed shifts. Based on quantitative **1**3C-NMR data, several important structural parameters including the percentage of mono-, di-, tri-, and tetrasubstituted phenyl rings in the polybenzyl can be calculated. The extent of branching in a number of polybenzyls prepared under different experimental conditions was determined. The results indicate an increase in branching with the increase in reaction temperature.