On the Synergy of Coulombic and Chelate Effects in Bidentate Diboranes: Synthesis and Anion Binding Properties of a Cationic 1,8-Diborylnaphthalene
On the Synergy of Coulombic and Chelate Effects in Bidentate Diboranes: Synthesis and Anion Binding Properties of a Cationic 1,8-Diborylnaphthalene
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双齿乙硼烷中库仑效应和螯合效应的协同作用：阳离子 1,8-二硼基萘的合成和阴离子结合性能
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
F. Gabbaï
中科院分区：
文献类型：
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作者：
Haiyan Zhao;F. Gabbaï
作为双齿刘易斯酸阴离子络合化学研究的一部分，我们进行了1-（二均三甲苯基硼基）-8-（1′-硼杂-9 ′-硫杂蒽基）萘（1）与三氟甲磺酸甲酯的反应。该反应通过硫原子的烷基化进行，得到由外围锍单元修饰的双齿乙硼烷（[2]+）。这种新的乙硼烷以三氟甲磺酸盐的形式被分离出来，它与氟离子和叠氮离子反应，分别形成相应的阴离子螯合物2-μ2-F和2-μ2-N3。在氯仿中进行的滴定实验表明，[2]+的氟化物结合常数超过1至少4个数量级。这些结果得到了光谱、结构和计算数据的支持，表明螯合效应和库仑效应是相加的，可以结合起来提高双齿刘易斯酸的阴离子亲和力。
As part of our investigation in the chemistry of bidentate Lewis acids for anion complexation, we have carried out the reaction of 1-(dimesitylboryl)-8-(1′-bora-9′-thia-anthryl)naphthalene (1) with methyltriflate. This reaction proceeds via alkylation of the sulfur atom to afford a bidentate diborane ([2]+) decorated by a peripheral sulfonium unit. This new diborane, which has been isolated as the triflate salt, reacts with both fluoride and azide anions to form the corresponding anion chelate complexes 2-μ2-F and 2-μ2-N3, respectively. Titration experiments carried out in chloroform indicate that the fluoride binding constant of [2]+ exceeds that of 1 by at least 4 orders of magnitude. These results, which are supported by spectroscopic, structural, and computational data, show that chelate and Coulombic effects are additive and can be combined to boost the anion affinity of bidentate Lewis acids.