The first example of a transition metal (BB)-carboryne complex containing two boron atoms of the icosahedral cage connected to a single exohedral metal center (POBBOP)Ru(CO)2 (POBBOP = 1,7-OP(i-Pr)2-2,6-dehydro-m-carborane) was synthesized by double B–H activation within the strained m-carboranyl pincer framework. Theoretical calculations revealed that the unique three-membered (BB)>Ru metalacycle is formed by two bent B–Ru σ-bonds with the concomitant increase of the bond order between the two metalated boron atoms. The reactivity of the highly strained electron-rich (BB)-carboryne fragment with small molecules was probed by reactions with electrophiles. The carboryne–carboranyl transformations reported herein represent a new mode of cooperative metal–ligand reactivity of boron-based complexes.

The kinetics of RAFT inverse miniemulsion polymerization of acrylamide are presented. The polymerizations exhibit typical behavior of controlled polymerizations under conditions where the hydrolytic degradation of the RAFT agent is less favorable. The effects of different reaction parameters such as temperature, initiator concentration, pH of the aqueous phase, RAFT agent, and surfactant concentration on RAFT inverse miniemulsion polymerization are presented. The particle nucleation process in the inverse miniemulsion polymerizations is evaluated by the use of radical scavengers. The presence of RAFT agent was found to have a significant impact on the particle nucleation process. The fate of desorbed monomeric radicals in inverse miniemulsion polymerizations is evaluated by the comparison of the rates of propagation, re-entry, and termination. One of the potential reasons for the induction time observed in the RAFT inverse miniemulsion polymerizations is suggested to be associated with desorption of monomeric and oligomeric radicals from the particles to the continuous oil phase.

The ruthenium carboranyl pincer complex featuring fluxional ”cage-walking“ of the metal center is an efficient catalyst for cyclooctane transfer dehydrogenation.

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Assembly of bimetallic complexes on boron clusters by coordination of coinage metal cations to Ru–B single bonds.

We report the synthesis of the chelating phosphinite-arm carboranyl POBOP-H (POBOP = 1,7-OP(i-Pr) 2 -m-carboranyl) ligand precursor, preparation of its rhodium complexes, and their reactivity in oxidative addition/reductive elimination reactions. The oxidative addition of iodobenzene to the low-valent (POBOP)Rh(PPh 3 ) resulted in the selective formation of the 16-electron complex (POBOP)Rh(Ph)(I), featuring a highly strained exohedral rhodium−boron bond. The complex (POBOP)-Rh(Ph)(I) is the first example of a B-carboranyl aryl metal complex, which is a proposed intermediate in metal-promoted B−C coupling reactions. The complex (POBOP)Rh(Ph)(I) was selectively and directly converted, in the presence of acetonitrile, to (POB(BPh)OP)Rh(H)(I)(CH 3 CN) (POB(BPh)OP = 1,7-OP(i-Pr) 2 -2-Ph-m-carboranyl) through unprecedented cascade reductive elimination of the phenyl-B-carboranyl and the oxidative addition of a vicinal B−H bond of the boron cluster to the metal center, exhibiting both metal-and cluster-centered reactivity.

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