Etienne Garand

Our research effort is aimed at providing a molecular level understanding of complex chemical reaction dynamics and mechanisms. We employ a combination of mass spectrometry, laser spectroscopy and electronic structure calculations to probe the reaction intermediates directly involved in a broad array of chemical systems such as green energy production, organic synthesis, molecular recognition and biological processes.

Our strategy involves the isolation of intermediates and transient complexes from solution using variants of electrospray ionization which allow for the retention of condensed-phase structure and primary solvent interactions. These species are then cooled (∼10 K) in a cryogenic ion trap to lock their fluxional motion into a plethora of well-defined local minima along the complex reactive landscape. The cold molecules are separated according to their molecular mass before being interrogated by precise, isomer-selective, vibrational and electronic spectroscopy. This approach thus yields snapshots of the key species involved in various chemical reactions and processes which can be compared with theoretical predictions and connected with observed kinetics and selectivity.

Current areas of interest are:

• Mechanisms and intermediates in homogenous catalytic H₂O oxidation and CO₂ reduction for solar fuels production.
• Metal-alkane interactions involved in selective C-H activation and functionalization.
• Excited state energetics and couplings in organic chromophores for singlet fission and solar cell applications.
• Roles of non-covalent interactions (H-bonding, Pi-stacking, hydrophobic interactions, etc) and solvent effects in site-selective catalysis, molecular recognition and tertiary structure of biopolymers
• Instrumentation and methodology development for analytical applications requiring the high sensitivity of mass spectrometry and precise structural characterization of infrared spectroscopy

The scope of our experimental physical chemistry research program, which effectively bridges theoretical predictions with contemporary applications of carefully designed molecular systems, is well centered within the greater chemistry community. Our approach is designed to be very versatile in order to tackle the ever-evolving landscape of chemical problems involving molecular interactions. We also strongly encourage and value collaborative work on specific problems with organic, organometallic and chemical biology research groups.

Students in our lab develop a versatile skill set which includes: scientific instrument design and building, laser science and spectroscopy, mass spectrometry techniques, basic synthesis, and electronic structure calculations.