Cyclic peroxides are highly reactive oxygen-containing species that play important roles in chemical synthesis. Now, the reaction between diazoboranes and triplet oxygen affords a family of cyclic dio...

Acenes are attractive molecular platforms with characteristic π-electron delocalization, resulting in exceptionally small HOMO–LUMO gaps, which makes them valuable for use in a variety of organic elec...

Borenium ions are tricoordinate boron cations of the type [LBR2]+, where L is a donor ligand. While the inherently reactive nature of these Lewis acidic species has been harnessed to advance bond acti...

MIT chemists designed a fluorescent molecule they hope could be used for applications such as generating clearer images of tumors. The dye is based on a borenium ion — a positively charged form of bor...

Reported boryl anions (R2B–) often exhibit n–p conjugation between the boron atom and adjacent heteroatoms, with their nucleophilicity being the primary focus. In this work, we present evidence that a...

The synthesis and redox transformations of 6,12-diboraindeno[1,2-b]fluorene (DBIF)─a pentacyclic π-system with diboron incorporation─are reported. In notable contrast to the all-hydrocarbon indenofluo...

In recent years, neutral NHC-stabilized boryl radicals have been investigated as reactive species in various organic transformations. However, cationic boron radicals have been significantly less explored. In addition, boron-centered open-shell species with S > 1/2 have emerged as attractive synthetic targets. In this study, we provide a synthetic route to an NHC-stabilized boryl radical cation as a salt of the weakly coordinating [Al(ORF)4]− (RF = C(CF3)3) anion. The synthetic procedure was extended to dicationic diboron derivatives of Schlenk’s and Thiele’s hydrocarbons with meta- and para-phenylene coupling units between the spin centers. While most known isolable boron biradicals have a singlet ground-state with a thermally accessible triplet state, the boron version of Schlenk’s hydrocarbon occupies a ground-state triplet spin-state, as shown by combined electron paramagnetic resonance spectroscopy and density functional theory studies. Furthermore, initial reactivity studies of the dications with elemental sulfur and diphenyldiselenide are presented.

ConspectusBoron heterocycles represent an important subset of heteroatom-incorporated rings, attracting attention from organic, inorganic, and materials chemists. The empty pz orbital at the boron cen...

Although the activation of elemental sulfur by main group compounds is well-documented in the literature, the products of such reactions are often heterocyclic in nature. However, the isolation and ch...

A Lewis acidic carbodicarbene-stibenium ion mediates C(sp3)−H and C(sp)−H bond breaking of acetonitrile and terminal alkynes in the presence of an organic base. The resulting adducts were reacted wit...

Designing molecules that can undergo late-stage modifications resulting in specific optical properties is useful for developing structure-function trends in materials, which ultimately advance optoele...

Diazo compounds and organic azides are widely used as reagents for accessing valuable molecules in multiple areas of fundamental and applied chemistry. Their capacity to undergo versatile chemical tra...

Low-valent antimony and bismuth have emerged as novel platforms for achieving reversible small-molecule activation at main-group metals. Although various examples of oxidative addition reactions at mo...

Systems that possess open- and closed-shell behavior attract significant attention from researchers due to their inherent redox and charge transport properties. Herein, we report the synthesis of the first diborepin biradicals. They display tunable biradical character based on the steric and electronic profile of the stabilizing ligand and the resulting geometric deviation of the diborepin core from planarity. While there are numerous all-carbon-based biradical systems, boron-based biradical compounds are comparatively rare, particularly ones in which the radical sites are disjointed. Calculations using density functional theory (DFT) and multireference methods demonstrate that the fused diborepin scaffold exhibits high biradical character, up to 95%. Use of a nonsterically demanding diaminocarbene promotes the planarization of the pentacyclic framework, resulting in the synthetic realization of a diborepin containing a dibora-quinoidal core, which possesses a closed-shell ground state and thermally accessible triplet state. The biradicals were structurally authenticated and characterized by both solution and solid-state electron paramagnetic resonance (EPR) spectroscopy. Half-field transitions were observed at low temperatures (about 170 K), confirming the presence of the triplet state. Initial reactivity studies of the biradicals led to the isolation and structural characterization of bis(borepin hydride) and bis(borepin dianion).

Borenium ions have traditionally served as main group (pre-)catalysts, and their use in materials-related applications have been limited by their instability. Now, a series of fully π-conjugated azabo...