Research Areas:

inorganic chemistry, catalysis, organometallics, boron clusters, small molecule transformations.

Our main focus is on the synthesis of new, unusual, and reactive molecules: inorganic ligands, organic products, and organometallic complexes. Researchers in the group are involved in a range of projects from exploratory organometallic synthesis, studies of mechanisms of catalytic reactions and their applications in organic synthesis. Students with interest in catalysis, inorganic, and organometallic chemistry are encouraged to join. Group members will receive a rigorous training in inorganic and organometallic chemistry, catalysis, air-free synthetic methods, and spectroscopic methods.

Metals Complexes of Multidentate Carborane-Backbone Ligands

We employ polyhedral boron clusters, such as icosahedral carboranes C2B10H12, as a chemically versatile platform for synthesis of reactive transition metal complexes designed for small molecule activation and group transfer. Carborane clusters provide a unique combination of extreme steric hindrance and unusual electronic effects with either C–M, B–M, or B–H∙∙∙M coordination to a metal center. Three-dimensional icosahedral boron cages provide an unusual coordination environment of five neighboring cluster atoms to an exohedral metal center, which is patently different from planar aryl- and pyridine-backbone ligands. We utilize hemilabile vicinal bridging B–H∙∙∙M interactions to stabilize low-coordinate metal center configurations and to enforce metal-ligand cooperative reactivity.

Recently, we synthesized carborane-based complexes that exhibited a group transfer chemistry from the metal center to the boron cluster. In addition, we discovered 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, which is an inorganic boron-based analog of benzynes.

Representative publications:
Expansion of the (BB)>Ru Metallacycle with Coinage Metal Cations: Formation of B-M-Ru-B (M = Cu, Ag, Au) Dimetalacyclodiboryls
Chemical Science 2018, 9, 2601–2608.
Rapid Reversible Borane to Boryl Hydride Exchange by Metal Shuttling on the Carborane Cluster Surface Chemical Science 2017, 8, 5399-5407.
(BB)-Carboryne Complex of Ruthenium: Synthesis by Double B–H Activation at a Single Metal Center
Journal of the American Chemical Society 2016, 138, 10531–10538.

Cage-Driven Transformations of Boron Clusters

We discovered the novel type of metal-free activation of strong bonds that is driven by the unusual electronic structure and rearrangement of boron cages. Recent results include activation of B–H and O–H bonds under mild conditions.

Representative publications:
Reversible Water Activation Driven by Contraction and Expansion of the 12-vertex-closo-12-vertex-nido Biscarborane Cluster
Chemical Communications 2016, 52, 12710–12713.

Chemistry of Strongly Lewis-Acidic Metal Halides

We work on new modes of activation of organic substrates by a cooperative action of high-valent transition metal complexes and sterically hindered nucleophiles. Our recent findings include the novel activation of nitriles with direct formation of zwitterionic vinylimido complexes. The scope of the reaction includes a range of substituted unactivated nitriles.

Representative publications:
Activation of C–H Bonds of Alkyl- and Arylnitriles by the TaCl5–PPh3 Lewis Pair
Inorganic Chemistry 2017, 56, 11798–11803.
Formation of a Cationic Vinylimido Group upon C-H Activation of Nitriles by Trialkylamines in the Presence of TaCl5.
Inorganic Chemistry 2016, 55, 5101–5103.