SEQUENTIAL SUBSTITUTION REACTIONS ON B10H10-2 AND B12H12-2
SEQUENTIAL SUBSTITUTION REACTIONS ON B10H10-2 AND B12H12-2
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DOI：
10.1063/1.1701367
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发表时间：
1962-01-01
影响因子：
4.4
通讯作者：
LIPSCOMB, WN
中科院分区：
文献类型：
--
作者：
HOFFMANN, R;LIPSCOMB, WN
与硼氢化物及其离子相比，D_4d_（12）O_（10）H_（10）O_（10）~（-2）和二十面体硼氢化物的B_（12）H_（12）~（-2）是非常稳定的，可视为假芳族化合物。它们还被证明[4]形成了一系列非常有趣的取代衍生物，但尚未完全鉴定，类型为BlOH1O_nXn-2，其中O =; n =; 1 O，X= F、Cl、Br或I。这表明可以制备大量顺序取代的衍生物，这使得我们对B10 H10 -2和B12 H12 -2离子的反应性进行预测，以努力包括未取代和取代的多面体离子中的共振和诱导效应，如通过我们对B10 H10 -2和B12 H12 -2的LCAO-MO描述的扩展所表述的。我们对最初的预测感到鼓舞，实验2证实了这一点。图4表明，D+的明显亲电攻击似乎在两个顶点处产生了BlOH 10 -2的优先交换，这两个顶点比其他八个B原子带更多的负电荷。根据一个具体的例子，这里研究的问题如下：假设卤素的攻击是亲电的，并且连续的
IN comparison with boron hydrides and their ions the closed polyhedral Bl oHlO-2 of D4d symmetryI· 2 and B12H12-2 of icosahedral symmetry3 are so extraordinarily stable that they can be regarded as pseudoaromatic in character. They have also been reported4 to form a very interesting series of substitution derivatives, as yet incompletely identified, of the type BlOHlO_ nXn-2 where O::; n::; lO, and X= F, Cl, Br, or I. This indication that a large number of sequentially substituted derivatives can be prepared has led us to make predictions of reactivities of the B10HlO-2 and B12H12-2 ions in an effort to include resonance and inductive effects in unsubstituted and substituted polyhedral ions as formulated by an extension of our LCAO-MO descriptions· of B10HlO-2 and B12H12-2. We are encouraged by the initial prediction, verified by experiment2. 4 that apparent electrophilic attack by D+ appears to produce preferential exchange in BlOH10-2 at the two apices, which are more negatively charged than the eight other B atoms. Formulated in terms of a specific example, the question investigated here is the following: Suppose that attack by a halogen is electrophilic and that successive