Rodrigues Silva Daniela, de Azevedo Santos Lucas, Koning Matthijs A J G, Fonseca Guerra Célia, Hamlin Trevor A
Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
Phys Chem Chem Phys. 2025 Jun 11;27(23):12569-12576. doi: 10.1039/d5cp01533b.
The chemical bond between halogenated borane Lewis acids and a variety of Lewis bases of varying strength (from strong to weak: NH, MeCN, N) has been quantum chemically explored using dispersion-corrected relativistic density functional theory (DFT) at ZORA-BLYP-D3(BJ)/TZ2P. We propose a unified picture of chemical bonding that exists on a continuum where weaker van der Waals (commonly referred to as "noncovalent") interactions at longer distances transition into stronger donor-acceptor (commonly referred to as covalent) complexes at shorter distances. Remarkably, depending on the strength of the Lewis base, an intermediate regime is observed where both van der Waals and donor-acceptor complexes are observed. This study demonstrates that a covalent component is ubiquitous across the bonding spectrum, with the stability of the minima on potential energy surfaces determined by the strength of the Lewis acid-base interaction. We advocate for classifying Lewis pairs as strongly or weakly bonded based on whether their covalent interaction is strong enough to overcome the geometric penalty of bond formation. This work elucidates the fuzzy boundaries within chemical bonding.
利用ZORA-BLYP-D3(BJ)/TZ2P水平的色散校正相对论密度泛函理论(DFT),对卤化硼烷路易斯酸与各种强度不同的路易斯碱(从强到弱:NH、MeCN、N)之间的化学键进行了量子化学研究。我们提出了一种统一的化学键图景,它存在于一个连续体上,在较长距离处较弱的范德华(通常称为“非共价”)相互作用在较短距离处转变为较强的供体-受体(通常称为共价)配合物。值得注意的是,根据路易斯碱的强度,会观察到一个中间区域,其中同时存在范德华配合物和供体-受体配合物。这项研究表明,共价成分在整个键合谱中普遍存在,势能面上极小值的稳定性由路易斯酸碱相互作用的强度决定。我们主张根据路易斯对之间的共价相互作用是否强到足以克服键形成的几何惩罚,将其分类为强键合或弱键合。这项工作阐明了化学键内的模糊边界。