Acke Guillaume, Van Damme Sofie, Havenith Remco W A, Bultinck Patrick
Ghent Quantum Chemistry Group, Department of Inorganic and Physical Chemistry, Faculty of Science, Ghent University, Faculty of Science, Krijgslaan 281, S3, Ghent, 9000, Belgium.
Theoretical Chemistry, Zernike Institute for Advanced Materials and Stratingh Institute for Chemistry, University of Groningen, Groningen, AG, 9747, The Netherlands.
J Comput Chem. 2018 Apr 5;39(9):511-519. doi: 10.1002/jcc.25095. Epub 2017 Nov 2.
The zz component of the nucleus independent chemical shift or the NICSzz is commonly used as a quantifier of the (anti)aromatic character of a (sub)system. One of the underlying assumptions is that a position can be found where the "aromatic" ring currents are adequately reflected in the corresponding NICSzz value. However, as the NICSzz is the result of an integration over the entire space, it no longer explicitly contains the information needed to quantify the separate contributions arising from underlying current density patterns. In this study, we will show that these contributions can be revealed by resolving the NICSzz into orbitals, sign, and positions. Our analysis of benzene in terms of these resolutions shows that the same underlying current density can lead to highly complex shielding patterns that vary greatly depending on the position of the NICSzz-probe. As such, our results indicate that any analysis solely based on NICSzz-values can lead to results that are difficult to interpret, even if the system under study is considered to be well-known. © 2017 Wiley Periodicals, Inc.
核独立化学位移的zz分量（即NICSzz）通常用作（子）体系（反）芳香性的量化指标。其潜在假设之一是，能够找到一个位置，使得“芳香”环电流在相应的NICSzz值中得到充分反映。然而，由于NICSzz是整个空间积分的结果，它不再明确包含量化由潜在电流密度模式产生的单独贡献所需的信息。在本研究中，我们将表明，通过将NICSzz分解为轨道、符号和位置，可以揭示这些贡献。我们根据这些分解对苯进行的分析表明，相同的潜在电流密度可能导致高度复杂的屏蔽模式，这些模式会因NICSzz探针的位置而有很大差异。因此，我们的结果表明，即使所研究的体系被认为是众所周知的，任何仅基于NICSzz值的分析都可能导致难以解释的结果。© 2017威利期刊公司
