Reaction mechanism of diphenylborinic acid with D-fructose in aqueous solution
Reaction mechanism of diphenylborinic acid with D-fructose in aqueous solution
复制标题
二苯基硼酸与D-果糖在水溶液中的反应机理
DOI：
10.1016/j.molliq.2015.07.062
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
and Koji Ishihara
中科院分区：
文献类型：
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作者：
Yukika Sobue;Tomoaki Sugaya;Satoshi Iwatsuki;Msahiko Inamo;Hideo D. Takagi;Akira Odani;and Koji Ishihara
对d-果糖与d-果糖不能三齿配位的二苯硼酸（Ph 2 B（OH））反应进行动力学研究，以解决反应机理，为解决硼酸（RB（OH）2）与d-果糖的两步反应机理找到线索。标题反应为一步反应，在Ph_2B（OH）上有大量过量的果糖存在，反应符合准一级反应条件，表明RB（OH）_2与果糖的反应是先快速形成二配位络合物，然后缓慢形成三配位络合物. Ph 2B（OH）的动力学反应性远高于其共轭碱二苯基硼酸根离子（Ph 2B（OH）2−）。结果表明，Ph 2B（OH）2−与CHES缓冲液相互作用形成外球复合物，而Ph 2B（OH）与CHES缓冲液之间没有观察到相互作用。游离的硼酸根离子和被束缚在外球络合物中的硼酸根离子分别与果糖通过稳定的二元和三元外球络合物形成螯合物。
The reaction ofd-fructose with diphenylborinic acid (Ph2B(OH)), to whichd-fructose cannot coordinate tridentately, was kinetically investigated in order to solve the reaction mechanism, and to find a clue to resolve the two-step reaction mechanism of boronic acid (RB(OH)2) withd-fructose. The title reaction was a single-step reaction under the pseudo first-order conditions with large excessd-fructose over Ph2B(OH), which suggests that the reaction of RB(OH)2withd-fructose consists of the fast formation of a two-coordinate complex followed by the slow formation of a three-coordinate complex. The kinetic reactivity of Ph2B(OH) was considerably higher than that of its conjugate base, diphenylborinate ion (Ph2B(OH)2−). It was shown that Ph2B(OH)2−interacted with CHES buffer to form an outer-sphere complex, whereas no interaction was observed between Ph2B(OH) and CHES buffer. Both the free borinate ion and the restrained borinate ion into the outer-sphere complex react withd-fructose to form the chelate complex via stable binary and ternary outer-sphere complexes, respectively.