Reply to the Comment on 'Realization of Lewis Basic Sodium Anion in the NaBH3- Cluster'

摘要

We reply to the comment by S. Pan and G. Frenking who challenged our interpretation of the Na-:-> BH3 dative bond in the recently synthesized NaBH3- cluster. Our conclusion remains the same as that in our original paper (https:// doi.org/10.1002/anie.201907089 and https://doi.org/10.1002/ange.201907089). This conclusion is additionally supported by the energetic pathways and NBO charges calculated at UCCSD and CASMP2(4,4) levels of theory. We also discussed the suitability of the Laplacian of electron density (OTAIM) and Adaptive Natural Density Partitioning (AdNDP) method for bond type assignment. It seems that AdNDP yields more sensible results. This discussion reveals that the complex realm of bonding is full of semantic inconsistencies, and we invite experimentalists and theoreticians to elaborate this topic and fcisolutions incorporating different views on the dative bond. Chemical bond is a key concept in chemistry and related sciences. The paradox is that despite being intuitive and used for centuries, chemical bond still lacks a rigorous physical definition. From a quantum mechanical point of view, there is no corresponding operator to claim a bond to be an observable physical quantity. This physical limitation is still pushing hot debates among experimentalists and theoreticians and has led to a pronounced diversity of chemical bond definitions. Nevertheless, some golden standards are widely accepted by the chemical community, including the classical Lewis definition (which exists for more than a century)([1,2]) and recommendations documented by IUPAC.([3])