Two-dimensional arrangements of bis(haloethynyl)benzenes combining halogen and hydrogen interactions

The electronic distribution of some haloethynylbenzene derivatives may favor 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, 1,4-bis(bromoethynyl)benzene, and 1,3-bis(iodoethynyl)benzene were used as halogen bond donors and 1,2-bis(4-pyridyl)ethylene, pyridazine, propanone, hexamethylenetetramine, and 2,8-dimethyl-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine (Tröger’s base) 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 basis set superposition error 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, noncovalent interaction methodology was also applied.Thanks are given to Crystallography Service from the University of Zaragoza (Spain), University of Pais Vasco (Spain), and National University of Singapore. This work was supported by the Ministerio de Economia y Competitividad, under the projects MAT2012-38538-C03-01, MAT2014- 55205-P, Fondo Europeo de Desarrollo Regional (FEDER), and Gobierno de Aragon. L.G. thanks the Ministerio Economia y Competitividad and J.M. thanks Ministerio de Educacion Cultura y Deporte for a grant (FPU14/06003).Peer reviewe