B-O BOND LENGTHS IN BORON-OXYGEN COMPOUNDS
B-O BOND LENGTHS IN BORON-OXYGEN COMPOUNDS
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DOI：
10.1107/s0567740868001846
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发表时间：
1968-01-01
期刊：
影响因子：
--
通讯作者：
DINGLE, TW
中科院分区：
文献类型：
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作者：
COULSON, CA;DINGLE, TW
一个简单的分子轨道处理的z-电子在各种各样的平面硼-氧化合物显示，键长的变化合理地解释在n-键顺序。与简单的Htickel方法相比，m技术方法在这里没有任何优势。在大多数硼氧化合物中，硼原子与三个或四个氧原子键合。在后一种情况下，四个BO键围绕硼原子四面体排列。当只形成三个键时，硼原子被三个氧原子对称地包围，所有四个原子近似地位于同一平面上。三角BO键的键长在1.28 - 1.43 3 3，.由于硼-氧骨架是平面的，因此可以合理地假设，作为第一近似，波函数可以分为a-和n-分子轨道。然后，类似于碳zc-电子系统，键长的任何差异都可能归因于n-键级的差异。因此，应该可以将标准的Hfickel型分析应用于含有三角键合的硼原子的分子。n键理论在BO键中的应用很少。Coulson（1964）用简单的n键理论解释了偏硼酸中内部和外部BO键之间键长的差异。Mateson（1960）用它来关联涉及取代的亚乙基硼酸的反应速率。Armstrong & Perkins（1967）使用更复杂的Pariser-Parr-Pople（PPP）方法研究了一些取代的苯基硼酸。所有
A simple molecular-orbital treatment of the z-electrons in a large variety of planar boron-oxygen compounds shows that variations in bond length are reasonably well explained in terms of a n-bond order. The m-technique method is of no advantage here as compared with the simple Htickel method.In most boron-oxygen compounds, the boron atom is bonded to three or four oxygen atoms. In the latter case, the four BO bonds are arranged tetrahedrally around the boron atom. When only three bonds are formed, the boron atom is surrounded symmetrically by three oxygen atoms, all four atoms lying approxi-mately in the same plane. The bond length of the trig-onal BO bond varies over the range 1.28 to 1.43 3,. Since the boron-oxygen framework is planar, it is reasonable to assume that, as a first approximation, the wave function can be divided into a-and n-mo-lecular orbitals. Then, in analogy to carbon zc-electron systems, any differences in bond length might be attri-buted to differences in n-bond order. Therefore, it should be possible to apply a standard Hfickel type analysis to molecules containing trigonally bonded boron atoms. Applications of n-bond theory to BO bonds are rare. Coulson (1964) has used simple n-bond theory to explain the differences in bond length between the interior and exterior BO bonds in metaboric acid. Mateson (1960) has used it to correlate reaction rates of reactions involving substituted ethyleneboronic acids. Armstrong & Perkins (1967) have used the more sophisticated Pariser-Parr-Pople (PPP) method to in-vestigate some substituted phenylboronic acids. All