Tetraiododiborane(4) (B2 I4 ) is a Polymer Based on sp3 Boron in the Solid State

The Field of Main Group Lewis Acids and Lewis Superacids: Important Basics and Recent Developments

New developments in the field of Lewis acidity are highlighted, with the focus of novel Lewis acids and Lewis superacids of group 2, 13, 14, and 15 elements. Several important basics, illustrated by modern examples (classification of Donor-Acceptor (DA) complexes, amphoteric nature of any compound in terms of DA interactions, reorganization energies of main group Lewis acids and the role of the energies of frontier orbitals) are presented and discussed. It is emphasized that the Lewis acidity phenomena are general and play vital role in different areas of chemistry: from weak "atomophilic" interactions to the complexes of Lewis superacids.

On-chip mid-infrared optical sensing with GeSbSe waveguides and resonators

We fabricated single mode Ge₂₈Sb₁₂Se₆₀ waveguides and resonators using e-beam lithography and achieved a propagation loss of 3.88 dB/cm at 3.66 µm. We compared BCl₃ and CHF₃ etch chemistries and determined CHF₃ produced 1.5 dB/cm higher propagation losses at 3.6 µm due to C-H bond absorption. We use fabricated waveguides to detect an aromatic aldehyde dissolved in a non-polar solvent with a limit of detection of 1.09 µmol/mL. We then reduce this detection limit to 0.25 µmol/mL using the enhancement produced by a chalcogenide ring resonator.

Tetraiododiborane(4) (B2 I4 ) is a Polymer Based on sp3 Boron in the Solid State

Herein we present the first solid‐state structures of tetraiododiborane(4) (B₂I₄), which was long believed to exist in all phases as discrete molecules with planar, tricoordinate boron atoms, like the lighter tetrahalodiboranes(4) B₂F₄, B₂Cl₄, and B₂Br₄. Single‐crystal X‐ray diffraction, solid‐state NMR, and IR measurements indicate that B₂I₄ in fact exists as two different polymeric forms in the solid state, both of which feature boron atoms in tetrahedral environments. DFT calculations are used to simulate the IR spectra of the solution and solid‐state structures, and these are compared with the experimental spectra.