PHOTOPOLYMERIZATION OF CARBON-DISULFIDE YIELDS THE HIGH-PRESSURE-PHASE (CS2)(X)

Irradiation of carbon disulfide vapor at 313 nm produces a solid aeros ol of nanosized particles, which slowly aggregate and settle. Elementa l analysis shows the composition of the solid is CS (1.98), and the de nsity is 1.92 +/- 0.03 g/cm(3). Physical properties of this material w ere found to be nearly identical to Bridgman's black carbon disulfide, which is prepared from liquid CS2 at pressures above 40 kbar and temp eratures around 150 degrees C. The IR spectrum of (CS2)(x) includes fe atures at 1410 (s, br), 1298 (ms), 1250 (m), 1067 (vs), 891(w), 854 (v w), 821(w), 550 (w), 507 (w), 471 (m), and 447 cm(-1) (m). The (CS2)(x ) polymer undergoes photooxidation (lambda less than or equal to 500 n m) in the presence of molecular oxygen to produce CO, OCS, SO2, CS2, s ulfur, and a partially oxidized polymer. The relative amounts of these products vary widely with the specific experimental conditions employ ed. Vibrational spectroscopic studies of ((CS2)-C-13)(x), and the mate rial prepared by irradiating a 50/50 mixture of (CS2)-C-13/(CS2)-C-12, suggest that it predominantly consists of highly S-S cross-linked cha ins of (CS2)(x). This provides a convenient low-pressure route to an u nusual phase of CS2 and helps elucidate the primary process in the pho tolysis of CS2 vapor.