As halogen bonds gain prevalence in supramolecular synthesis and materials chemistry, it has become necessary to examine more closely how such interactions compete with or complement hydrogen bonds whenever both are present within the same system. As hydrogen and halogen bonds have several fundamental features in common, it is often difficult to predict which will be the primary interaction in ...

Halogen bonds are shown to possess the same characteristics as hydrogen bonds: charge transfer, resonance assistance and cooperativity. This follows from the computational analyses of the structure and bonding in N-halo-base pairs and quartets. The objective was to achieve an understanding of the nature of resonance-assisted halogen bonds (RAXB): how they resemble or differ from the better unde...

The title compound, C(14)H(10)Cl(4), is easily crystallized while the other enanti-omorph only forms an oil upon crystallization attempts. The title compound has a considerably higher density, ρ ≃ 1.562 Mg m(-3) compared to the racemic substance, ρ ≃ 1.514 Mg m(-3). This is supported by the fact there are two inter-molecular halogen-halogen contacts in the title compound compared with only one ...

Thiophene, a key building block for the construction of conjugated materials, has been scarcely studied in halogen bonding (XB)-driven self-assemblies. In present study, two thiophene derivatives modified at position 3 were (co-)crystallized using complementary XB donor/acceptor functional groups. Single-crystal X-ray diffraction analysis confirmed presence and chalcogen acting, most cases, con...

Adhesion molecules hold cells together but also couple cell membranes to a contractile actomyosin network, which limits the expansion of cell contacts. Despite their fundamental role in tissue morphogenesis and tissue homeostasis, how adhesion molecules control cell shapes and cell patterns in tissues remains unclear. Here we address this question in vivo using the Drosophila eye. We show that ...

Halogen bonding, due to its directionality and tunable strength, is being increasingly utilized in self-assembling materials and crystal engineering. Using density functional theory (DFT) and molecular mechanics (OPLS/CM1Ax) calculations, multiply halogen bonded complexes of brominated imidazole and pyridine are investigated along with their potential in construction of self-assembling architec...

We report the first UV-vis spectroscopic study of bromine molecules confined in clathrate hydrate cages. Bromine in its natural hydrate occupies 51262 and 51263 lattice cavities. Bromine also can be encapsulated into the larger 51264 cages of a type II hydrate formed mainly from tetrahydrofuran or dichloromethane and water. The visible spectra of the enclathrated halogen molecule retain the spe...

The competition between hydrogen- and halogen-bonding interactions in complexes of 5-halogenated 1-methyluracil (XmU; X = F, Cl, Br, I, or At) with one or two water molecules in the binding region between C5-X and C4=O4 is investigated with M06-2X/6-31+G(d). In the singly-hydrated systems, the water molecule forms a hydrogen bond with C4=O4 for all halogens, whereas structures with a halogen bo...

The title compound, C13H2F10N2O, has been previously described in the space group Pbca with Z = 8 [Jai-nhuknan et al. (1997 ▶). Acta Cryst. C53, 455-457]. The current P212121 polymorph was obtained from a tetra-hydro-furan solution. The penta-fluoro-phenyl rings make dihedral angles of 50.35 (6) and 54.94 (6)° with the urea fragment, in close accord with those reported for the first polymorph. ...

Crystallization of tri-O-[p-halobenzoyl]-myo-inositol 1,3,5-orthoformates from ethyl acetate-petroleum ether solution produced concomitant dimorphs that have different halogen bonding contacts; the kinetic form with C-Br...O-C contacts upon heating to 185 degrees C, converts completely to the thermodynamic form with C-Br...O=C contacts via crystal-to-crystal first order phase transition.