Photodissociation of ICN at 266 nm and BrCN at 230 nm using brute force orientation

This Letter presents measurements of the CN fragment from photolysis of BrCN at 230 nm and ICN at 266 nm. Supersonically cooled samples were spatially oriented using a strong uniform electric field. An enhanced signal from the CN fragment of ICN was seen when the dissociation laser was polarized parallel to the orientation field, and the degree of enhancement agreed with calculation of a pure parallel transition. Dissociation of BrCN displayed an enhancement which fell below the upper limit assuming a pure parallel transition at a rotational temperature of 1.5 K, implying contributions from a perpendicular transition. (C) 1999 Elsevier Science B.V. All rights reserved.