Intermolecular Interactions in Bromo-, Methyl-, and Cyanoimidazole Derivatives

Abstract

Materials containing bistable N−H•••N hydrogen bonds, such as imidazole crystals, show promise for applications in electronics. Herein, we examine the effect of imidazole functionalization upon structural parameters relating to proton transfer, molecular rotation, and order−disorder transitions. Three different substituents are studied: methyl-, bromo-, and cyano-, resulting in steric, electronic, and supramolecular modification of the imidazole core.

Halogen⋯halogen interactions in diiodo-xylenes

“…The iodines are not equivalent in the solid state; I 4A participates in one type II I … I interaction via its electrophilic tip (halogen-bond donor), and I 4B is the halogen-bond acceptor in this interaction via its electron rich belt. Angles are 88.15(15)˚ for θ 1 and 166.00 (14)˚ for θ 2 shown in Fig. 6a and these reasonably conform to the standard parameters for type II interactions.…”

“…Successful approaches to the probing of halogen … halogen interactions in aromatic structures generally involve the incorporation of strong electron-withdrawing groups such as iodofluoroarenes. 13 These electron withdrawing groups serve to increase the Lewis acidity of the halogen, 14 which is important as competition for the halogen σ-hole from nonhalogen electron-rich functionality is likely to occur. 15 Despite such interest in halogen … halogen interactions, systematic solid-state investigations of these interactions in organic molecules are relatively rare.…”

A ferrocene imidazolium-based macrocycle as an electrochemical chemosensor for halide anions

“…2, 3 packs into 1D chains through imidazole⋯imidazole N-H⋯N hydrogen bonds, as is typical for protic imidazole derivatives 36,37 (the previously reported structure of 1-ferrocenylimidazole 34 does not pack in this manner, due to the lack of a protic nitrogen group). The hydrogen bonding geometries are typical of such interactions 36,37 [N-H⋯N = 2.867(4) Å, ∠N-H⋯N = 170°]. The imidazole C4 and C5 hydrogen atoms are oriented towards the cyclopentadienyl ring of the ferrocene moiety, possibly due to weak attractive interactions between the electron deficient imidazole C-H groups and electron rich cyclopentadienyl group.…”

“…‡ As shown in Fig. 2, 3 packs into 1D chains through imidazole⋯imidazole N-H⋯N hydrogen bonds, as is typical for protic imidazole derivatives 36,37 (the previously reported structure of 1-ferrocenylimidazole 34 does not pack in this manner, due to the lack of a protic nitrogen group). The hydrogen bonding geometries are typical of such interactions 36,37 [N-H⋯N = 2.867(4) Å, ∠N-H⋯N = 170°].…”

Diazole-based powdered cocrystal featuring a helical hydrogen-bonded network: Structure determination from PXRD, solid-state NMR and computer modeling

“…[62] dmim crystallizes with three molecules in the asymmetric unit (Figure 1, right), with two of the molecules mutually antiparallel (173.5° rotation between the two rings) and the third is distinctly out of plane (rotated by 72.7° and 67.8° compared to the adjacent imidazoles), taking part in an interchain C−H•••π interaction, electrostatically driven by theelectron-rich nature of the ring compared to the protons. Overall, each H-bonded chain has become helicoidal, with both being represented in the extended structure due to the centrosymmetric space group (P2 1 /c) [62]. As mentioned before, dmpz presents both a H-bond donor and a H-bond acceptor site, forming trimers in the solid-state(Figure 1, left).…”