XE-129 NMR-STUDIES OF HYPER-CROSS-LINKED POLYARYLCARBINOLS - RIGID VERSUS FLEXIBLE STRUCTURES

Xenon NMR is used with adsorption measurements to infer information ab out the microstructure of some novel hyper-cross-linked polyarylcarbin ols. It is shown that rigidrod connecting units are necessary for micr oporosity in these systems, as hyper-cross-linked polymers based on fl exible structures are found to have conventional surface areas and xen on NMR spectra. A microporous polymer based on rigid triarylcarbinol m onomers shows high xenon uptake and a linear chemical shift variation with pressure at room temperature. Spin-lattice relaxation and cross-p olarization dynamics are studied at low temperatures. In this regime t he xenon has extremely long equilibration times, and the adsorption dy namics are complicated but give important insight into the polymer top ology. The data are compared with two possible models of the polymer m icrostructwre.