Two-Dimensional Arrangements of Bis(haloethynyl)benzenes Combining Halogen and Hydrogen Interactions

Abstract

The electronic distribution of some haloethynylbenzene derivatives may favour the formation of two-dimensional organizations by combining halogen and hydrogen bonds. In order to highlight this strategy we have prepared seven cocrystals and analyzed their structures. 1,4-Bis(iodoethynyl)benzene (p-BIB), 1,4-bis(bromoethynyl)benzene (p-BBrB) and 1,3bis(iodoethynyl)benzene (m-BIB) were used as halogen bond donors and 1,2-bis(4-pyridyl)ethylene (BPE), pyridazine, propanone, hexamethylenetetramine (HTMA) and 2,8-dimethyl-6H,12H-5,11methanodibenzo[b,f][1,5]diazocine (Tröger's base, TB) were employed as halogen bond acceptors. The crystal structures of seven halogen-bonded complexes show C−X•••Y (X = I, Br; Y = N, O) distances shorter than the sum of the van der Waals radii and six of them contain the edge-to-edge C−H•••X (X = I, Br) supramolecular hydrogen bond synthon. The stabilization energies with BSSE correction of hydrogen bond synthons have been determined by DFT calculations, and they are in the range 2.9 to 5.7 kcalmol-1. To gain a deeper understanding of these interactions, Non-Covalent Interactions (NCI) methodology was also applied.

Short X···N Halogen Bonds With Hexamethylenetetraamine as the Acceptor

“…HMTA produces an array of structural diversity due to its peculiar diamondoid-like skeleton and polydentate coordination nature. A Cambridge Structural Database (CSD, 2020 ) search for HMTA functioning as an XB acceptor revealed 27 hits, of which 2, 12, 4, and 8 hits correspond to mono- (Eia et al, 1956 ; Pritzkow, 1975a ), bi- (Eia et al, 1956 ; Dahl et al, 1971 ; Pritzkow, 1975b ; Walsh et al, 2001 ; Raatikainen and Rissanen, 2011 ; Syssa-Magalé et al, 2014 ; Gonzalez et al, 2017 ; Szell et al, 2019 ), tri- (Hassel et al, 1954 ; Eia et al, 1956 ; Dahl and Hassel, 1965 ), and tetradentate (Pritzkow, 1974 ; Raatikainen and Rissanen, 2011 , 2012 ) coordination modes ( Figure 1 ). Bidentate HMTA is frequently encountered in halogen- and hydrogen-bonded complexes.…”

Real-Space Approach to the Reaction Force: Understanding the Origin of Synchronicity/Nonsynchronicity in Multibond Chemical Reactions

“…44 Namely, it has proved to be a useful tool in the study of a broad range of non-covalent interactions, such as hydrogen and halogen bonds, as well as in the design of hybrid materials, among many others. [47][48][49] A color code is used to differentiate the type of interaction. Namely, strong attractive interactions, such as hydrogen bonds, are depicted in blue; very weak interactions, such as van…”

Simple iodoalkyne-based organocatalysts for the activation of carbonyl compounds

“…Therefore, haloalkynes can form strong, directional and selective halogen bonds, which makes them suitable for being used as organocatalysts. 18,19 Moreover, iodoalkynes are stable towards nucleophiles and elevated temperatures and easily accessible from terminal alkynes, 20 which allows to modify the number and arrangement of halogen bond donors, their solubility and their rigidity or flexibility among other characteristics. However, to the best of our knowledge, there is only one example where a perfluorinated iodoethynyl compound has been used as a catalyst.…”