Chalcogen-Bonding Interactions in Telluroether Heterocycles [Te(CH2 )m ]n (n=1-4; m=3-7).

Marko Rodewald,Wolfgang Weigand,J Mikko Rautiainen,Tobias Niksch,Raija Oilunkaniemi,Helmar Görls,Risto S Laitinen

doi:10.1002/chem.202002510

Abstract

The Te⋅⋅⋅Te secondary bonding interactions (SBIs) in solid cyclic telluroethers were explored by preparing and structurally characterizing a series of [Te(CH2)m]n (n=1–4; m=3–7) species. The SBIs in 1,7‐Te2(CH2)10, 1,8‐Te2(CH2)12, 1,5,9‐Te3(CH2)9, 1,8,15‐Te3(CH2)18, 1,7,13,19‐Te4(CH2)20, 1,8,15,22‐Te4(CH2)24 and 1,9,17,25‐Te4(CH2)28 lead to tubular packing of the molecules, as has been observed previously for related thio‐ and selenoether rings. The nature of the intermolecular interactions was explored by solid‐state PBE0‐D3/pob‐TZVP calculations involving periodic boundary conditions. The molecular packing in 1,7,13,19‐Te4(CH2)20, 1,8,15,22‐Te4(CH2)24 and 1,9,17,25‐Te4(CH2)28 forms infinite shafts. The electron densities at bond critical points indicate a narrow range of Te⋅⋅⋅Te bond orders of 0.12–0.14. The formation of the shafts can be rationalized by frontier orbital overlap and charge transfer.

Highlights

Chalcogen bonding, which has recently been formally defined by IUPAC,[1] is a special class of secondary bonding interactions (SBIs), a term that was originally coined by Alcock.[2]
Chalcogen bonds are most prominent for the heavy chalcogen atoms tellurium and selenium and resemble the halogen,[1a,3] pnictogen and tetrel bonds[4,5] of the heavy p-block elements
The preparations were modelled after those of Morgan and co-workers, who have reported the synthesis of Te(CH2)4 from elemental tellurium and I(CH2)4I,[15] and of Te(CH2)5 from Al3Te2 and Br(CH2)5Br.[16]

Summary

Introduction

Chalcogen bonding, which has recently been formally defined by IUPAC,[1] is a special class of secondary bonding interactions (SBIs), a term that was originally coined by Alcock.[2]. The dispersion effects become more significant with increasing period number and play the major role in the interactions between the heaviest pblock elements This contribution is concerned with chalcogen bonds involving tellurium atoms. Macrocyclic unsaturated chalcogenoethers are another class of compounds that can further our understanding of chalcogen bonds These types of compounds have been extensively studied both computationally and experimentally by Gleiter and co-workers.[6a,e–h,10] Due to the chalcogen-bonding interactions, the ring molecules are often packed in a columnar fashion to form tubular lattices. This packing of cyclic species is mimicked by some related acyclic dimethyl polyalkynyl diseleno- and ditelluroethers.[11]. The nature of the molecular packing in the lattices was explored by solid-state DFT (PBE0-D3/pob-TZVP) calculations involving periodic boundary conditions

Results and Discussion

Conclusion

Conflict of interest