Redox-active carborane clusters in bond activation chemistry and ligand design.

Icosahedral closo-dodecaboranes have the ability to accept two electrons, opening into a dianionic nido-cluster. This transformation can be utilized to store electrons, drive bond activation, or alter coordination to metal cations. In this feature article, we present cases for each of these applications, wherein the redox activity of carborane facilitates the generation of unique products. We highlight the effects of exohedral substituents on reactivity and the stability of the products through conjugation between the cluster and exohedral substituents. Futher, the utilization of the redox properties and geometry of carborane clusters in the ligand design is detailed, both in the stabilization of low-valent complexes and in the tuning of ligand geometry.

Paramedic-Performed Carotid Artery Ultrasound Heralds Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest: A Case Report.

Point-of-Care Ultrasound (POCUS) has been demonstrated to have multiple applications in the care of critically ill and injured patients, especially given its portability and ease of use. These characteristics of POCUS make it ideal for use in the prehospital environment as well. We present a case that highlights a novel application of ultrasound in the prehospital management of out-of-hospital cardiac arrest (OHCA).

Activation of Alkynes by a Redox-Active Carboranyl Diphosphine and Formation of Boron-Containing Phosphacycles.

In this work, we report the reactivity of the carboranyl diphosphine, 1-PtBu2-2-PiPr2-C2B10H10, with terminal alkynes, resulting in the formation of boron-containing phosphacycles. The reported system combines the nucleophilic activation of electron-deficient terminal alkynes via electron-rich phosphine groups with the redox behavior of carborane clusters to promote a sequence of metal-free intramolecular B-H bond activation and cyclization, creating an alkenylphosphonium cycle fused with a reduced open nido-carborane cluster.

Metal-Free Bond Activation by Carboranyl Diphosphines.

We report metal-free bond activation by the carboranyl diphosphine 1-PtBu2-2-PiPr2-C2B10H10. This main group element system contains basic binding sites and possesses the ability to cycle through two-electron redox states. The reported reactions with selected main group hydrides and alcohols occur via the formal oxidation of the phosphine groups and concomitant reduction of the boron cage. These transformations, which are driven by the cooperation between the electron-donating exohedral substituents and the electron-accepting cluster, differ from those of "regular" phosphines and are reminiscent of oxidative addition to transition metal centers, thus representing a new approach to metal-free bond activation.