PUB - Publikationen an der Universität Bielefeld

The geometric and electronic structure of [Hg(o-C6F4)]3 (1) in the gas phase, i.e. free of intermolecular interactions, was deter-mined by a synchronous gas-phase electron diffraction/mass spec-trometry experiment (GED/MS), complemented by quantum chemi-cal calculations. 1 is stable up to 498 K and the gas phase contains a single molecular form: the trimer [Hg(o-C6F4)]3. It has a planar structure of D3h sym-metry with a Hg-C distance of 2.075(5) A and a Hg-Hg distance of 3.614(7) A (both rh1). Structural differences between the crystalline and gaseous state have been analyzed. Different DFT functio-nal-basis combi-na-tions were tested, demon-stra-ting the importance to consider the relativistic effects of the mercury atoms. The combi-na-tion PBE0/-MWB(Hg),cc-pVTZ(C,F) turned out to be the most appro-priate for the geometry optimization of such organomercurials. The elec-tronic structure of 1, the nature of the chemical bonding in C-Hg-C fragments and the nature of the Hg···Hg inter-actions have been analyzed in terms of the Natural Bond Orbital (NBO) and Quantum Theory of Atoms in Molecules (QTAIM) approaches. The influence of the nature of halogen substi-tution on the structure of the molecules in the series [Hg(o-C6H4)]3, [Hg(o-C6F4)]3, [Hg(o-C6Cl4)]3, [Hg(o-C6Br4)]3 was also analyzed. © 2024 Wiley‐VCH GmbH.