- 作者: 潘貫; 徐明達
- 作者服務機構: Chemistry Research Center, National Taiwan University
- 中文摘要:
The reaction rate for the reduction of cyanocobalamin (B12) with Ti(III) in HCl and KCl solutions at constant ionic strength was followed by spectrophotometric measurements at 15°, 20°, 25° and 30℃. The reaction rate was found to be of pseudo-first-order with respect to B12 and of second-order with resoect to B12 and Ti(III) in HCl solutions. The second-order rate constant was given by K0= {k1k2k3/(k_1 k_2)}/{1+(k1/ k_1)[H+]+Kb} for the processes, (I) B12+H2O+……HB…, (II)
k2
HB..+Ti(III)……(Bridged compound, X)+H+, and (III) X→B12r+Ti(IV). The values of K0 obtained were 0.80~1.29 liter mole¯1 sec¯1 in the range of ionic strength 0.2~0.5M at 30°. The average activation energy was 20.5 kcal mole¯1. - 英文摘要: --
- 中文關鍵字: --
- 英文關鍵字: --