Our research goal, broadly stated, is to create new transition metal complexes which have the capability of unusual reactivity, even new reactivity types.  These may be Lewis acid/base, hydrogen transfer, or redox. The reactivity always involves changes at the metal, but we have shown how our ligand, monoanionic “PNP”, an amide with two phosphine donor “arms,” can also be a reactive functionality: bond-making and -breaking involving substrate.

Our metal/substrate reactions are usually the stoichiometric modification of generally unreactive (“inert”) small molecules (N2, N2O, NO, CO2, olefins, but even alkanes and arenes);  these are sometimes catalytic. What we strive for are previously unachieved metal complexes and transformations: 14-valence electron complexes, radical hydrides, unusual metal oxidation states, unprecedented ligand binding geometries, very weak substrates, very low coordination numbers, etc. Creating the “unusual” can frequently enable accomplishing the “impossible.” Since we work in these underdeveloped areas, precedent is little guide for us and we often do molecular detective work, using an open mind and variety of physical and spectroscopic techniques: vibrational and multinuclear NMR spectroscopies, mass spectrometry, EPR, stable isotope labelling and mechanistic tracking. Most often, because we claim to be doing unprecedented things, final proof rests on X-ray diffraction determination of molecular structure: which atoms are bonded together, and whether each bond is single, double, triple, ..... or some weaker noncovalent interaction (e.g. agostic, hydrogen-bonded, or charge-controlled)? Answering these last questions is greatly facilitated by the results of Density Functional Theory (DFT) calculations on structure, bonding, and energy, as well as characterizing transition states of reaction mechanisms. In particularly exciting cases, DFT results precede experiment and guide experiment in the most productive directions.