A pulse molecular beam of Cl2SO was photodissociated at 248 and 193 nm. The time-of-flight distributions were observed for the photofragments, Cl, ClSO and SO. The primary processes are Cl + ClSO (I), 2Cl + SO (II) and Cl2 + SO (III). At 193 nm the measured translational energy distributions imply a vibrationally excited ClSO fragment in process (I), and a simultaneous dissociation in process (II). The relative quantum yield is φI < φII. At 248 nm a radical process (I) is dominant compared to a molecular process (III). 相似文献
In order to synthesize four stereoisomers of cystathionine (CYT), D- and L-homocysteines (D- and L-Hcy) were synthesized from methionine (Met) by a facile procedure. L-Met was reacted with dichloroacetic acid in concentrated hydrochloric acid under reflux to give (4S)-1,3-thiazane-2,4-dicarboxylic acid hydrochloride [(4S)-TDC.HCl]. L-Hcy was obtained by treatment of (4S)-TDC.HCl with hydroxylamine. D-Hcy was also synthesized from D-Met via (4R)-TDC.HCl intermediate. The obtained D- and L-Hcy were condensed with (R)- and (S)-2-amino-3-chloropropanoic acid hydrochlorides under alkaline conditions to give four stereoisomers of CYT. 相似文献
The permeability and diffusivity of hydrogen in molybdenum was measured by the time-lag method using molybdenum membranes prepared by electron beam melting and cleaned by argon ion etching. Measurements were also made on membranes prepared in this manner and subsequently coated with palladium. The inconsistencies in the previous data, a consequence of surface effects, have been clarified. The activation energy for H-diffusion in Mo is 10.6 KJ/mol. 相似文献
The effect of anharmonicity in the residual molecule A-B in the photodissociation process A-B-C + hv → A-B + C is examined. It is shown that even if the transition probability for the V-T energy transfer process A-B (u = n) + C → A-B (v ? n') + C is not appreciably affected by the anharmonicity, the partial linewidth can be dramatically modified. 相似文献
