Photodissociation of gaseous 2-nitrophenol at 266 and 355 nm was investigated by probing the nascent OH products with the laser-induced-. uorescence (LIF) technique. Rotational state distributions of the OH photofragments were measured and characterized by Boltzmann temperatures of 900 +/- 40 K and 1070 +/- 80 K at 266 and 355 nm, respectively. The OH photoproducts were found to be vibrationally cold at both photolysis wavelengths. Preferential populations of the OH F-1 (Pi(3/2)) spin-orbit state and Pi(+)Lambda-doublet state were observed at both photolysis wavelengths. We have proposed a mechanism for OH production involving the photoisomerization to form aci-nitro isomers, which then dissociate into OH fragments. (C) 2008 Elsevier B.V. All rights reserved.