EXPERIMENTS ON THE GENERATION OF 2-COORDINATE PHOSPHORYL SPECIES BY FRAGMENTATION OF 7-PHOSPHANORBORNENE AND 3-PHOSPHOLENE DERIVATIVES

2,6-Di-tert-butyl-4-methylphenylphosphenite (ArOP=O) was released into the gas phase on heating a neat sample of a 7-phosphanorbornene deriv ative 6 bearing this aryloxy substituent at 300-degrees-C (0.01 mm). A ttempts to prepare 1-adamantyl phosphenite similarly were not successf ul. Irradiation of 6 in 1,2-dichloroethane at 254 nm failed to cause r elease of the phosphenite, but when some alcohol was present fragmenta tion proceeded readily to give the H-phosphonate (ArOPH(O)OR). It was deduced that the species undergoing the fragmentation was a 5-coordina te adduct of 6 and the alcohol. Similar behavior was observed for the other esters and also for a P-phenyl oxide and a P-phenyl sulfide in t he 7-phosphanorbornene series, as well as for a 3-phospholene oxide. I sotope exchange experiments with (OH2)-O-18 proved the influence of th e irradiation on the formation and fragmentation of the 5-coordinate a dduct. Earlier literature reports that 2-coordinate species are releas ed on irradiation of 7-phosphanorbornene and 3-phospholene derivatives therefore need reinterpretation.