Intramolecular charge shift reaction, rate constants

A large red shift observed in polar solvents was indicative of the intramolecular charge transfer character of the triplet state. The change of dipole moment accompanying the transition Tj - Tn, as well as rate constants for electron and proton transfer reactions involving the T state of a-nitronaphthalene, were determined. The lower reactivity in polar solvents was attributed to a reduced n-n and increased charge transfer character of the triplet state... 

Study of the role of counterions and solvents on ion-pairing effects which influence charge-transfer reactions of donor-acceptor model compounds has continued with a study of bicyclooctatetraenyl dianion (1 )." Rate constants have been determined, by NMR spectroscopy, for bond shift (A bs) and intramolecular charge transfer (fccr) in the alkali metal salts (1 /2M+) in THF-solvent-separated ion pairs (SSIPs) (l /2Na+) is the first example of a sodium salt of a dianion to undergo charge transfer by SSIPs and it is surmized that formation of the sodium-bridged CIP transition structure is relatively unfavourable. 

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