In the crystal structure of the title compound, C29H8F16I4O4, short I⋯I and I⋯F contacts, which can be understood as halogen bonds (XBs), represent the strongest inter-molecular inter-actions, consistent with the presence of I and F atoms, and the absence of H atoms, at the periphery of the mol-ecule. In addition, π-π stacking inter-actions between tetra-fluoro-iodo-phenyl (TFIP) groups and fiv...

In the title compound, C10H4Br2O3, the atoms of the 6,8-di-bromo-chromone unit are essentially coplanar [largest deviation from the mean planes = 0.1109 (3) Å] and the formyl group is twisted slightly with respect to the attached ring [C-C-C-O torsion angles = 11.5 (4) and -168.9 (3)°]. In the crystal, mol-ecules are linked to each other through halogen bonds [Br⋯O = 3.118 (2) Å, C-Br⋯O = 162.3...

Introduction Conclusions References

Cl/Br/I alternative substitutions in a series of dihalophenols indicate that type I and type II halogen···halogen contacts have different chemical nature. Only the latter ones qualify as true halogen bonds, according to the recent IUPAC definition.

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...

Recent studies indicated that gaseous halogens mediate key tropospheric chemical processes. The inclusion of halogen-ozone chemistry in atmospheric box models actually closes the approximately 50% gap between estimated and measured ozone losses in the marine boundary layer. The additional source of gaseous halogens is deemed to involve previously unaccounted for reactions of O(3)(g) with sea su...

Reactive halogens are responsible for boundarylayer ozone depletion and mercury deposition in Polar Regions during springtime. To investigate the source of reactive halogens in the air arriving at Barrow, Alaska, we measured BrO, an indicator of reactive halogen chemistry, and correlated its abundance with airmass histories derived from meteorological back trajectories and remotely sensed sea i...

Astatine (Z = 85) is the heaviest member of the elements of group 17 of the Periodic System (halogens). About 20 isotopes are known, and some of them have been identified as short-lived products in the natural radioactive series. The longest-lived isotope is 210At with a half-life of only 8.3 hours. Consequently, macroscopic quantities of this element cannot be accumulated. Our knowledge on its...

We have assessed the feasibility of producing heavy negative ion beams as drivers for an inertial confinement fusion reactor. Negative ion beams offer the potentially important advantages relative to positive ions that they will not draw electrons from surfaces and the target chamber plasma during acceleration, compression and focusing, and they will not have a low energy tail. Intense negative...