Triplet state of α-nitronaphthalene

Abstract

Nanosecond flash photolysis studies of α-nitronaphthalene (α-NO₂C₁₀H₇) in polar and nonpolar solvents have led to the detection of the triplet–triplet absorption spectrum of this nitrocompound. The large red shift observed in polar solvents is indicative of the intramolecular charge transfer character of the triplet state. The change of dipole moment accompanying the transition T₁→ T_n, as well as rate constants for electron and proton transfer reactions involving the T₁ state of α-NO₂C₁₀H₇, were determined. The lower reactivity in polar solvents is attributed to a reduced n-π* and increased charge-transfer character of the triplet state.