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

Abstract

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.