Room temperature bimolecular rate constants for the reactions :

1 NH + N₂H₄ ---> products

k₁ = (3.6 ± 2.2) x 10⁻¹⁵ cm³ molec⁻¹s⁻¹

2 NH + NO ---> products

k₂ = (5.78 ± 0.64) x 10⁻¹¹ cm³ molec⁻¹s⁻¹

3 NH + NO₂ ---> products

k3 = (1.61 ± 0.14) x 10⁻¹¹ cm³ molec⁻¹s⁻¹

4 BH + NO ---> products

k₄= (15.6 ± 2.3) x 10⁻¹¹ cm³ molec⁻¹s⁻¹

5 BH + C₂ H₄ ---> products

k₅ = (14.4 ± 1.7) x 10⁻¹¹ cm³ molec⁻¹s⁻¹

have been measured along with upper limits for the reaction rates of :

6 BH + O₂ ---> products

k₆ < 1.1 x 10⁻¹¹ cm³ molec⁻¹s⁻¹

7 BH + CH₄ ---> products

k₇ < 9.4 x 10⁻¹³ cm³ molec⁻¹s⁻¹

8 BH + C₂ H₆ ---> products

k₈ < 1.6 x 10⁻¹² cm³ molec⁻¹s⁻¹

9 BH + CO ---> products

k₉< 1.3 x 10⁻¹³ cm³ molec⁻¹s⁻¹

All rates were measured at 1 torr buffer pressure. The effect of temperature on the rate constants for reactions 2,3,4 and 5 has been investigated along with the effect of varying the nature of the third body. NH (X, ³∑⁻) was generated from KrF 248.5 nm excimer laser photolysis of hydrazine and detected by laser induced fluorescence at 336 nm (A--> X, Q(0,0)). BH (X, ¹∑) was produced from ArF 193 nm excimer laser photolysis of diborane and the concentration was monitored by 433.4 nm laser induced fluorescence of the A--> X, Q(0,0) transition. Ab-initio calculations of species important on the potential energy surfaces of the systems:

NH + NO, NO₂

NH₂ + NO, NO₂

BH +NO

BH₂ + NO

have been carried out in order to compliment the data obtained in the above, and future, experiments. Prompt emission observed in the 193 nm photolysis of diborane has been characterized. The emission bands and probable emitters (in brackets) were:

249.7, 208.9 nm (Boron atomic lines) *

254 - 326 nm (BH3*)

320 - 340 nm (BH₂*)

366 - 388 nm (BH3*)

423 - 450 nm (BH A - X)

Assignment of the probable emitter was based on band structure, thermochemistry and observed power dependence of each of the bands. The two bands attributed to BH3* are the first experimentally detected electronic transitions for this important species. The band attributed to B H₂* is also a new transition.

An apparatus capable of generating a pulsed supersonic molecular beam has been constructed. Software and hardware to determine the translational temperature for species in the beam has been developed and temperatures for beams of various species have been measured.