Comment on "The Nature of Chalcogen-Bonding-Type Tellurium-Nitrogen Interactions": Fixing the Description of Finite-Temperature Effects Restores the Agreement Between Experiment and Theory

The Field of Main Group Lewis Acids and Lewis Superacids: Important Basics and Recent Developments

New developments in the field of Lewis acidity are highlighted, with the focus of novel Lewis acids and Lewis superacids of group 2, 13, 14, and 15 elements. Several important basics, illustrated by modern examples (classification of Donor-Acceptor (DA) complexes, amphoteric nature of any compound in terms of DA interactions, reorganization energies of main group Lewis acids and the role of the energies of frontier orbitals) are presented and discussed. It is emphasized that the Lewis acidity phenomena are general and play vital role in different areas of chemistry: from weak "atomophilic" interactions to the complexes of Lewis superacids.

Best-Practice DFT Protocols for Basic Molecular Computational Chemistry

Nowadays, many chemical investigations are supported by routine calculations of molecular structures, reaction energies, barrier heights, and spectroscopic properties. The lion's share of these quantum-chemical calculations applies density functional theory (DFT) evaluated in atomic-orbital basis sets. This work provides best-practice guidance on the numerous methodological and technical aspects of DFT calculations in three parts: Firstly, we set the stage and introduce a step-by-step decision tree to choose a computational protocol that models the experiment as closely as possible. Secondly, we present a recommendation matrix to guide the choice of functional and basis set depending on the task at hand. A particular focus is on achieving an optimal balance between accuracy, robustness, and efficiency through multi-level approaches. Finally, we discuss selected representative examples to illustrate the recommended protocols and the effect of methodological choices.

Reply to a Comment on "The Nature of Chalcogen-Bonding-Type Tellurium-Nitrogen Interactions"

We reply to the comment by J.‐M. Mewes, A. Hansen and S. Grimme (MHG), who challenged the accuracy of our r_e value for the N⋅⋅⋅Te distance in (C₆F₅)Te(CH₂)₃NMe₂ determined by gas electron diffraction (GED). We conclusively demonstrate that MHG′s quoted reference calculations are less accurate than they claim for solid state and gas phase. We show by higher level calculations, that we did not miss substantial contributions from open‐chain conformers. Refinements on simulated scattering data show that such contributions would have had only an almost negligible effect on r_e(N⋅⋅⋅Te). MHG suggested the use of a H0‐tuned GFN method for calculating vibrational corrections r_a−r_e, but this did not change these values substantially. Alternative amplitude calculations using higher level analytic harmonic and numeric cubic force fields (PBE0‐D3BJ/def2‐TZVP) yield a GED value for r_e(N⋅⋅⋅Te)=2.852(25) Å that is well within the experimental error of our original value 2.918(31) Å but far from the 2.67(8) Å predicted by MHG. A now improved error estimation accounts for inaccuracies in the calculated auxiliary values. The gas/solid difference of the weak N⋅⋅⋅Te interaction is in a realistic range compared to other systems involving weak chemical interactions.

We reply to the comment which challenged the accuracy of our r_e value for the N⋅⋅⋅Te distance in (C₆F₅)Te(CH₂)₃NMe₂ determined by gas electron diffraction. We show by higher level calculations, that we did not miss substantial contributions from open‐chain conformers.

Comment on "The Nature of Chalcogen-Bonding-Type Tellurium-Nitrogen Interactions": Fixing the Description of Finite-Temperature Effects Restores the Agreement Between Experiment and Theory

Mitzel and co-workers recently presented an intriguing molecule displaying a tellurium-nitrogen interaction. Structural data obtained in the solid and in gas phase indicated a large increase of the Te-N equilibrium distance re from 2.64 to 2.92 Å, respectively. Although some DFT calculations appear to support the large re in gas phase, we argue that the lions share of the increase is due to an incomplete description of finite-temperature effects in the back-corrected experimental data. This hypothesis is based on high-level coupled-cluster (CC) and periodic DFT calculations, which consistently point towards a much smaller re in the isolated molecule. Further support comes through MD simulations with a tuned GFN2-xTB Hamiltonian: Calibrated against a CC reference, these show a six-times larger influence of temperature than with the originally used GFN1-xTB. Taking this into account, the back-corrected re in gas phase becomes 2.67±0.08 Å, in good agreement with high-level CC theory and most DFT methods.