Probing Halogen Bonds by Scalar Couplings.

As halogen bonding is a weak, transient interaction, its description in solution is challenging. We demonstrate that scalar coupling constants () are modulated by halogen bonding. The binding-induced magnitude change of one-bond couplings, even up to five bonds from the interaction site, correlates to the interaction strength.

Halogen Bonding: An Odd Chemistry?

Halogen bonding is a flourishing field of research, but has for long been little recognized. The same goes for its scientific hero, Odd Hassel, who laid the foundations for all current developments. The crystallographic observation of halogen-oxygen interatomic distances shorter than the sum of the van der Waals radii of the involved atoms, and the interpretation of this phenomenon as a charge-transfer interaction, have been ground-breaking.

Halogen bonds of halonium ions.

Due to their electron deficiency, halonium ions act as particularly strong halogen bond donors. By accepting electrons in both lobes of their empty p-orbital, they are capable of simultaneously interacting with two Lewis bases. The interaction presumes the formation of three molecular orbitals and is accordingly typically entitled as a three-center halogen bond.

Fabrication of Porous Hydrogenation Catalysts by a Selective Laser Sintering 3D Printing Technique.

Three-dimensional selective laser sintering printing was utilized to produce porous, solid objects, in which the catalytically active component, Pd/SiO, is attached to an easily printable supporting polypropylene framework. Physical properties of the printed objects, such as porosity, were controlled by varying the printing parameters. Structural characterization of the objects was performed by helium ion microscopy, scanning electron microscopy, and X-ray tomography, and the catalytic performance of the objects was tested in the hydrogenation of styrene, cyclohexene, and phenylacetylene.

Surprising solvent-induced structural rearrangements in large [N···I···N] halogen-bonded supramolecular capsules: an ion mobility-mass spectrometry study.

Coordinative halogen bonds have recently gained interest for the assembly of supramolecular capsules. Ion mobility-mass spectrometry and theoretical calculations now reveal the well-defined gas-phase structures of dimeric and hexameric [N···I···N] halogen-bonded capsules with counterions located inside their cavities as guests. The solution reactivity of the large hexameric capsule shows the intriguing solvent-dependent equilibrium between the hexamer and an unprecedented pentameric [N···I···N] halogen-bonded capsule, when the solvent is changed from chloroform to dichloromethane.

Self-Complementary Dimers of Oxalamide-Functionalized Resorcinarene Tetrabenzoxazines.

Self-complementarity is a useful concept in supramolecular chemistry, molecular biology and polymeric systems. Two resorcinarene tetrabenzoxazines decorated with four oxalamide groups were synthesized and characterized. The oxalamide groups possessed self-complementary hydrogen bonding sites between the carbonyls and amide groups.

Tetrameric and Dimeric [N⋅⋅⋅I ⋅⋅⋅N] Halogen-Bonded Supramolecular Cages.

Tripodal N-donor ligands are used to form halogen-bonded assemblies via structurally analogous Ag -complexes. Selective formation of discrete tetrameric I L and dimeric I L halonium cages, wherein multiple [N⋅⋅⋅I ⋅⋅⋅N] halogen bonds are used in concert, can be achieved by using sterically rigidified cationic tris(1-methyl-1-azonia-4-azabicyclo[2.2.

[N⋅⋅⋅I ⋅⋅⋅N] Halogen-Bonded Dimeric Capsules from Tetrakis(3-pyridyl)ethylene Cavitands.

Two [N⋅⋅⋅I ⋅⋅⋅N] halogen-bonded dimeric capsules using tetrakis(3-pyridyl)ethylene cavitands with different lower rim alkyl chains are synthesized and analyzed in solution and the gas phase. These first examples of symmetrical dimeric capsules making use of the iodonium ion (I ) as the main connecting module are characterized by H NMR spectroscopy, diffusion ordered NMR spectroscopy (DOSY), electrospray ionization mass spectrometry (ESI-MS), and ion mobility-mass spectrometry (TW-IMS) experiments. The synthesis and effective halogen-bonded dimerization proceeds through analogous dimeric capsules with [N⋅⋅⋅Ag ⋅⋅⋅N] binding motifs as the intermediates as evidenced by the X-ray structures of (CH Cl ) @[3 a ⋅Ag ⋅(H O) ⋅OTs ] and (CH Cl ) @[3 a ⋅Ag ⋅(H O) ⋅OTs ], two structurally different capsules.