Spectroscopic Measurement of a Halogen Bond Energy

Halogen bonding (XB) has emerged as an important bonding motif in supramolecules and biological systems. Although regarded as a strong noncovalent interaction, benchmark measurements of the halogen bond energy are scarce. Here, a combined anion photoelectron spectroscopy and density functional theory (DFT) study of XB in solvated Br^? anions is reported. The XB strength between the positively‐charged σ‐hole on the Br atom of the bromotrichloromethane (CCl₃Br) molecule and the Br^? anion was found to be 0.63 eV (14.5 kcal mol^?1). In the neutral complexes, Br(CCl₃Br)_1,2, the attraction between the free Br atom and the negatively charged equatorial belt on the Br atom of CCl₃Br, which is a second type of halogen bonding, was estimated to have interaction strengths of 0.15 eV (3.5 kcal mol^?1) and 0.12 eV (2.8 kcal mol^?1).     

Atomic/Molecular Layer Deposited Iron–Azobenzene Framework Thin Films for Stimuli‐Induced Gas Molecule Capture/Release

The atomic/molecular layer deposition (ALD/MLD) technique provides an elegant way to grow crystalline metal–azobenzene thin films directly from gaseous precursors; the photoactive azobenzene linkers thus form an integral part of the crystal framework. Reversible water capture/release behavior for these thin films can be triggered through the trans–cis photoisomerization reaction of the azobenzene moieties in the structure. The ALD/MLD approach could open up new horizons for example, for the emerging fields of remotely controlled drug delivery and gas storage.