CYCLODEXTRIN-INDUCED FLUID SOLUTION ROOM-TEMPERATURE PHOSPHORESCENCE FROM ACENAPHTHENE IN THE PRESENCE OF 2-BROMOETHANOL

A 1:1 stoichiometric ratio and a formation constant of 130 l mol-1 were obtained for the binary inclusion complex between acenaphthene and beta-cyclodextrin (CD). On addition of 2-bromoethanol, effective quenching of the fluorescence emission and enhancement of the room-temperature phosphorescence (RTP) of acenaphthene is observed. The use of 2-bromoethanol as an external "heavy atom" to obtain room-temperature phosphorescence in fluid solutions is discussed. The RTP emission from acenaphthene included in beta-CD was optimized and characterized. The apparent formation constant of the ternary associate was determined to be 880 l mol-1 by the use of RTP enhancement in the presence of 1% 2-bromoethanol. The data indicate a ternary association between acenaphthene, beta-CD and the bromo alcohol. The use of sodium sulfite, for chemical deoxygenation, to obtain RTP emission from a non-heavy atom-containing luminophor is shown to be feasible. The kinetics of the deoxygenation reaction were established and a photochemical catalytic effect on the reaction was demonstrated.