ANALYSIS OF MACROCYCLIC POLYSTYRENES .1. LIQUID-CHROMATOGRAPHIC INVESTIGATIONS

Macrocyclic polystyrenes prepared by a single-step, pseudo-unimolecula r cyclization of a linear alpha-(diethoxyethyl)-omega-styrenylpolystyr ene can effectively be analyzed by liquid chromatography at the critic al point of adsorption. Using silica gel as the stationary phase and T HF-hexane as the eluent, the macrocyclic oligomers are separated from their linear precursors and other nonfunctional linear oligomers. The quantitative determination of the cyclization yield can be carried out via appropriate detector calibration for the linears and cyclics. Add itional information on the chemical structure of the linears and cycli cs is obtained by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. In conclusion, a possible cyclization mechanism is given including an interpretation of the MALDI behavior of the samples .