Chalcogen Bonds, Halogen Bonds and Halogen···Halogen Contacts in Di- and Tri-iododiorganyltellurium(IV) Derivatives

Abstract

In this manuscript, we have examined the CSD (Cambridge Structural Database) to investigate the relative ability of Te and I (in practice, the heaviest chalcogen and halogen atoms) in di- and tri-iododiorganyltellurium(IV) derivatives to establish σ-hole interactions. The geometry around the Te(IV) in this type of compound is trigonal bipyramidal where the stereoactive lone pair at Te(IV) occupies one of the equatorial positions. In the solid state, Te(IV) tends to form pseudo-octahedral coordination by establishing strong noncovalent interactions opposite to the two covalent bonds of the equatorial plane. Such contacts can also be classified as chalcogen bonds following the recommendation of the International Union of Pure and Applied Chemistry (IUPAC). Such contacts have been analyzed energetically in this work using density functional theory (DFT) calculations, rationalized using molecular electrostatic potential (MEP) surface analysis and characterized using a combination of the quantum theory of atoms in molecules (QTAIM) and noncovalent interaction plot (NCIplot) computational tools. Finally, the observation of halogen bonds and type I halogen···halogen contacts is also emphasized and compared to the chalcogen bonds. Energy decomposition analysis has also been performed to compare the physical nature of chalcogen, halogen and type I interactions.

Te⋯I secondary-bonding interactions in crystals containing tellurium(ii), tellurium(iv) and iodide atoms: supramolecular aggregation patterns, nature of the non-covalent interactions and energy considerations

“…21 However, systematic reviews of crystals featuring Se⋯O, 22 Se⋯N, 23,24 Se⋯π(aryl), 25 Te⋯N, 9 Te⋯I (ref. 26) and Te⋯π(aryl) 14 interactions confirm these contacts do not always arise from the interaction of a chalcogen-bound σ-hole with a nucleophile. Indeed, the situation is rather more complicated, especially in systems where an interacting atom forms multiple secondary-bonding interactions.…”

“…33,34 Instances of bifurcated 35–37 and charge-assisted 38,39 chalcogen bonds are also known. Computational chemistry calculations on the aforementioned neutral systems 31–37 and other non-charged systems 26,40 confirm that the energy imparted by the different interactions involving the tellurium are like or exceed those imparted by conventional hydrogen bonding. 41…”

“…33,34 Instances of bifurcated [35][36][37] and charge-assisted 38,39 chalcogen bonds are also known. Computational chemistry calculations on the aforementioned neutral systems [31][32][33][34][35][36][37] and other non-charged systems 26,40 confirm that the energy imparted by the different interactions involving the tellurium are like or exceed those imparted by conventional hydrogen bonding. 41 While the focus of the present study is upon the crystals, secondary-bonding interactions are known to persist in solution, 42,43 with recent studies highlighting the presence of intramolecular Te⋯F (ref.…”

The Unconventional Noncovalent Interactions Control: Crystallographic and Theoretical Analyses of the Crystalline Structure of 1,1′‐(1‐Chloro‐4‐methoxyphenyl)dibenzene as a Case Study

“…In case of Cl, despite their weak strength, type I Cl•••Cl contacts are known to be involved in the packing and properties of several molecular crystals. [31][32][33] The information provided clearly demonstrates that unconventional intermolecular interactions are of considerable importance. Therefore, it is essential to gain a better understanding of their chemical nature, interaction strength, and geometrical properties.…”

“…The X⋅⋅⋅X interactions have been classified based on the R−X ⋅⋅⋅X’ (θ1) and R−X’⋅⋅⋅X (θ2) angles, where classical hydrogen bonding (Type II) shows θ1≈180° with θ2≈90°, whereas if θ1≈θ2 the interaction is called of Type I. In case of Cl, despite their weak strength, type I Cl⋅⋅⋅Cl contacts are known to be involved in the packing and properties of several molecular crystals [31–33] …”