Interplay between theory and experiment: computational organometallic and transition metal chemistry.
Interplay between theory and experiment: computational organometallic and transition metal chemistry.
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DOI：
10.1021/ar9002027
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发表时间：
2010-02
影响因子：
18.3
通讯作者：
Zhenyang Lin
中科院分区：
文献类型：
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作者：
Zhenyang Lin
计算化学和理论化学提供了对分子的结构、性质和反应性的基本见解。因此，理论计算在化学研究和开发的各个领域都变得不可或缺。在这个账户中，我们介绍了我们在计算过渡金属化学领域的研究，用例子来说明理论如何影响我们对实验结果的理解，以及理论家和实验化学家之间的密切合作是如何互惠互利的。我们首先研究计算化学的使用，以阐明一些不寻常的化学键的细节。我们考虑了钛新世西格玛-硼烷络合物中的三中心、两电子成键和铑-铋络合物中的五中心、四电子成键。还研究了金属苯络合物中的成键作用。在每种情况下，理论计算都提供了对化学键的电子结构的特殊洞察。然后，我们给出一个例子，说明理论计算如何帮助确定Kappa(2)-N，N，N络合物的结构，该络合物是在加热中间苯腈配位络合物时形成的。根据合理的机理提出的初始X射线衍射结构似乎符合得很好，明显可接受的R值为0.0478。但当应用密度泛函理论计算时，优化后的几何构型与实验数据有很大的不同。通过将实验和理论相结合，我们提出了一个新的结构。值得注意的是，根据新结构对X射线衍射数据进行重新精炼后，R值略低，为0.0453。我们进一步考察了计算化学的使用，为C-H键激活机制提供了新的见解，并了解了亲核硼基配体的反应性性质，解决了计算方面的实验困难，反之亦然。最后，我们考虑了理论见解在三个非常具体的化学反应实验研究中的影响，说明了理论结果如何促进进一步的实验研究：(I)铜(I)硼配合物催化的醛的二硼化，(Ii)Ru催化的芳香族氮化物的C-H胺化，以及(Iii)乙烯基卡宾配合物的锌还原。这里给出的概念和例子是为非专业人士，特别是实验者准备的。它们一起展示了实验和理论的卓有成效的结合可能取得的一些成就。
Computational and theoretical chemistry provide fundamental insights into the structures, properties, and reactivities of molecules. As a result, theoretical calculations have become indispensable in various fields of chemical research and development. In this Account, we present our research in the area of computational transition metal chemistry, using examples to illustrate how theory impacts our understanding of experimental results and how close collaboration between theoreticians and experimental chemists can be mutually beneficial. We begin by examining the use of computational chemistry to elucidate the details of some unusual chemical bonds. We consider the three-center, two-electron bonding in titanocene sigma-borane complexes and the five-center, four-electron bonding in a rhodium-bismuth complex. The bonding in metallabenzene complexes is also examined. In each case, theoretical calculations provide particular insight into the electronic structure of the chemical bonds. We then give an example of how theoretical calculations aided the structural determination of a kappa(2)-N,N chelate ruthenium complex formed upon heating an intermediate benzonitrile-coordinated complex. An initial X-ray diffraction structure proposed on the basis of a reasonable mechanism appeared to fit well, with an apparently acceptable R value of 0.0478. But when DFT calculations were applied, the optimized geometry differed significantly from the experimental data. By combining experimental and theoretical outlooks, we posited a new structure. Remarkably, a re-refining of the X-ray diffraction data based on the new structure resulted in a slightly lower R value of 0.0453. We further examine the use of computational chemistry in providing new insight into C-H bond activation mechanisms and in understanding the reactivity properties of nucleophilic boryl ligands, addressing experimental difficulties with calculations and vice versa. Finally, we consider the impact of theoretical insights in three very specific experimental studies of chemical reactions, illustrating how theoretical results prompt further experimental studies: (i) diboration of aldehydes catalyzed by copper(I) boryl complexes, (ii) ruthenium-catalyzed C-H amination of arylazides, and (iii) zinc reduction of a vinylcarbyne complex. The concepts and examples presented here are intended for nonspecialists, particularly experimentalists. Together, they illustrate some of the achievements that are possible with a fruitful union of experiment and theory.