Using vector correlation to probe the influence of vibrational state selection on the photodissociation dynamics of HN3

State-selected photodissociation of hydrozoic acid is investigated by vibrationally exciting the molecule in the region of the second overtone of its N-H stretching motion (3ν1) and then photodissociating it using 532 nm light. Measurement of the resulting NH fragment rotational state distribution and vector correlation reveals that photodissociation from initial nuclear configurations with an extended N-H bond leads to a substantially hotter rotational state distribution as well as a more pronounced 〈vj〉 correlation than from nearly isoenergetic single-photon dissociation at 355 nm. These observations are interpreted as indicating that the region of the excited electronic surface accessed and hence the forces experienced by the molecule are different in the two isoenergetic photodissociation experiments.