| One of the goals of chemical dynamics is to investigate the moment during a reaction in which the fragile process of bond cleavage and formation occur, sometimes on a subpicosecond time scale. Technological limitations usually prevent the direct investigation of such short lived transition states. For the dynamicist who is not equipped with an elaborate femtosecond apparatus, there is still a way of studying short lived transition states. Conclusive information on the life-time and geometry of the transition state may be obtained by: (1) determining the partitioning of energy among the products of a reaction and (2) studying the preferred direction of motion, i.e. the anisotropy, of the receding fragments.; The first section of this dissertation presents the results of several photodissociation reactions. The use of isotopic substitution and alignment effects due to polarization of the photolyis light provide insight on the mechanism. All the experiments involve detecting an atomic species (H, D or S) using the classic technique of laser induced fluorescence. The molecules investigated are methanol, ethanol, dimethyl ether, ethylene sulfide, acetylene and ethylene.; The second section of this thesis discusses several bimolecular gas phase reactions. The reactions studied range from simple three body processes such as C({dollar}sp1{dollar}D) + H{dollar}sb2{dollar} and Hg({dollar}sp3{dollar}P{dollar}sb1{dollar}) + H{dollar}sb2{dollar}, to more complex reactions such as H or O({dollar}sp1{dollar}D) + acetylene and propyne. These experiments show how a vast amount of information can be obtained from the nascent Doppler profile of an atomic species produced from a reaction. |
