当前位置: X-MOL 学术Russ. J. Inorg. Chem. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Kinetics and Thermodynamics of the Template Synthesis and of an Acidic Decomposition of the Clathrochelate Iron(II) Tris-Cyclohexanedion-1,2-Dioximate (Nioximate) Formed by a Cross-Linking with Methylboronic Acid
Russian Journal of Inorganic Chemistry ( IF 1.8 ) Pub Date : 2020-10-30 , DOI: 10.1134/s0036023620100162
A. L. Pomadchik , A. S. Belov , E. G. Lebed , Ya. Z. Voloshin

Abstract—

The title complex is formed in a quantitative yield in diluted solutions and the kinetics of its template synthesis and its acidic decomposition were photometricaly studied. The effective synthesis rate constants were determined as the pseudo-first-order rate constants with respect to the concentration of Fe2+ ions. The orders with respect to those of nioxime, CH3B(OH)2 and H+ ions are equal to 3, 1 and –1, respectively. The plausible pathway of its assembly includes a reversible formation of the protonated pseudooctahedral iron(II) tris-nioximate, followed by its monodeprotonation and addition of CH3B(OH)2. Thus obtained pseudooctahedral intermediate undergoes a rate-determining stage of double cyclization with elimination of two molecules of water and structural rearrangement as well, thus giving the trigonal-prismatic iron(II) semiclathrochelate monocation. The latter complex easily undergoes a cross-linking with CH3B(OH)2, resulted in elimination of H+ ion and in formation of the title clathrochelate. Its acidic decomposition rate constants were also obtained as the pseudo-first-order rate constants, but with respect to the concentration of this complex. This rate substantially increases with increase in activity of H+ ions and decreases in the presence of CH3B(OH)2.



中文翻译:

甲基硼酸交联形成的笼形螯合物铁(II)三环己烷二酮-1,2-二氧肟酸酯(Nioximate)的模板合成和酸性分解的动力学和热力学

摘要-

在稀释溶液中以定量产率形成标题配合物,并对其光度法研究了其模板合成和酸性分解的动力学。将有效合成速率常数确定为相对于Fe 2+离子浓度的拟一级反应速率常数。关于尼肟,CH 3 B(OH)2和H +离子的顺序分别等于3、1和–1。其组装的可能途径包括可逆地形成质子化的伪八面体三氧肟酸铁(II),然后进行单去质子化并添加CH 3 B(OH)2。。如此获得的拟八面体中间体经历了双环化的速率确定阶段,其中消除了两个水分子并进行了结构重排,从而得到了三角棱晶型铁(II)半铁螯合物单阳离子。后者的络合物​​容易与CH 3 B(OH)2发生交联,从而消除H +离子并形成标题笼形螯合物。还获得了其酸性分解速率常数作为拟一级反应速率常数,但相对于该配合物的浓度而言。该速率随着H +离子活性的增加而显着增加,而在CH 3 B(OH)2的存在下降低。

更新日期:2020-10-30
down
wechat
bug