Observations of tetrel bonding between sp³-carbon and THF

Abstract

sp3-C⋯THF tetrel bonding was observed in the crystalline state and in the gas phase. Density functional calculations revealed interaction energies up to −11.2 kcal mol−1 and showed that these adducts are held together mainly by electrostatics.

Engineering Crystals Using sp3‐C Centred Tetrel Bonding Interactions

“…TCCP derivatives 1 and 2 are both synthetically accessible in moderate to decent yields (34-58 %) using as traightforward modified literature procedure (see experimental and ESI for full details and characterization). [21] Single crystals suitablef or X-ray diffractionm easurements (see experimental for details) were obtainedb ys low evaporation of as olution of 1 or 2 in dichloromethane. The atomicc oordinates contained within the unit cellsa re shown in Figure 2a and bf or 1 and 2 [23] respectively (see experimental for full details).…”

“…[20] We recently reported that the sp 3 -carbon tetrel bondingp otential of dimethyl-TCCP allows for supramolecular adduct formation with the electron-rich O-atom of tetrahydrofuran, both in the solid state and in the gas phase. [21] Here, we exploit and extend on this principle by demonstratingc rystal engineering with sp 3 -C tetrel bonding interactions using TCCP derivatives 1 and 2 ( Figure 1).…”

“…Compound 1 is the bulkier ethyl-derivative of the previously exploited dimethyl-TCCP. [21] Cyclopropane 2 can be seen as a cyclic ether analogue of 1,a nd was designed to combine a shole donor and acceptor within the same molecule. The Molecular Electrostatic Potential map (MEP) of 2 shown in Figure 1c learly illustrates that the cyclopropaner ing of 2 bears the large positive potential (a sort of hybrid of two sholes) located on the sp 3 C 2 (CN) 2 atoms (the MEP of 1 is comparable).…”

“…[20a, 22] It is worth mentioning that this potentiali si n-between the calculated potentialo nt he H-atomsi nw ater (+ 55 kcal mol À1 )a nd ammonia (+ 35 kcal mol À1 )w hen computed at the same level of theory. [21] The MEP of 1,4-dioxane shown in Figure 1i…”

Versatility of the Cyano Group in Intermolecular Interactions

“…This same phenomenon occurs on a divalent chalcogen Y atom, but each of its two RY bonds leads to a separate σ-hole, and a logical extension provides three σ-holes around a Z pnicogen atom in its ZR 3 configuration. Recent works [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ] have also included tetrel atoms T (C and Si, etc.) in this category, as the tetravalent TR 4 molecule has four σ-holes, so could, at least in principle, participate in as many as four simultaneous tetrel bonds.…”