Cyclohexanone oxime (CHO) and cyclopentanone oxime (CPO) in the vapor phase undergo N-OH bond scission upon excitation at 193 nm to produce OH, which was detected state selectively employing laser-induced fluorescence The measured energy distribution between fragments for both owns suggests that in CHO the OH produced is mostly vibrationally cold, with moderate rotational excitation whereas in CPO the OH fragment is also formed in upsilon '' = 1 (similar to 2%) The rotational population of OH (upsilon = 0 J) from CHO is characterized by a rotational temperature of 1440 +/- 80 K whereas the rotational populations of OH (upsilon = 0 J '') and OH (upsilon '' = 1 J '') from CPO are characterized by temperatures of 1360 +/- 90 K and 930 +/- 170 K respectively A high fraction of the available energy is partitioned to the relative translation of the fragments with f(T) values of 0 25 and 0 22 for CHO and CPO respectively In the case of CHO the A-doublet states of the nascent OH radical are populated almost equally in lower rotational quantum levels N with a preference for Pi(+) (A') states for higher N' However there is no preference for either of the two spin orbit states Pi(3/2) and Pi(1/2) of OH The nascent OH product in CPO is equally distributed in both A-doublet states of IT (A) and Pi(-) (A '') for all N '' but has a preference for the Pi(3/2) spin orbit state Experimental work in combination with theoretical calculations suggests that both CHO and CPO molecules at 193 nm are excited to the S-2 state which undergoes nonradiative relaxation to the T-2 state Subsequently molecules undergo the N-OH bond dissociation from the T-2 state with an exit barrier to produce OH (upsilon J)