Electronic transitions of protonated benzene and fulvene, and of C6H7 isomers in neon matrices.

ABSTRACT

Electronic transitions of protonated benzene (à (1)B(2)←X̃ (1)A(1), origin at 325 nm) and α-protonated fulvene (à (1)A'←X̃ (1)A', at 335 nm) trapped in 6 K neon matrices have been detected. The cations were produced from several different precursors, mass-selected, and co-deposited with neon. After neutralization of the cations, the electronic transitions of cyclohexadienyl (onsets at 549 and 310 nm) and α-hydrogenated fulvene (532 and 326 nm) radicals were identified. Upon excitation of cyclohexadienyl to the B̃ (2)B(1) state, photoisomerization to an open-chain structure and α-hydrogenated fulvene was observed.