Seminars Cycle

Nuclear Magnetic Resonance Expert visited the IMIT

Roderick Wasylishen is a prestigious researcher at the University of Alberta, from Canada.

During his stay in Corrientes, from September 8 to 12, the scientist Wasylishen worked in collaboration with the Atomic and Molecular Physics group led by Dr. Gustavo Aucar.

The Professor Wasylishen gave a seminar with members of different IMIT groups and FaCENA researchers, entitled «Tautomerism and hydrogen bonding in 1,3-diketones – Insights from Solid-State NMR Spectroscopy», on September 11 in the Department of Physics of the Faculty of Exact and Natural Sciences and Surveying (FaCENA).

Attached summary of the presentation

Our research has focused on 1H, 13C and 17O NMR studies of several 1,3-diketones that exist as the enol tautomer in the solid state (e.g., dibenzoylmethane).  The enol tautomer of these compounds are stabilized by intramolecular O–H–O hydrogen bonds, many of which are classified as low-barrier hydrogen bonds (i.e., O—-O separations less than ≈ 2.5 Å).  We have carried out systematic one- and two-dimensional NMR experiments of dibenzoylmethane and curcumin, both of which are examples of molecules that have LBHBs. Some interesting two-bond deuterium isotope effects on the 13C chemical shifts in the enol tautomer of 1,3-diketones will be presented.  As well, recent results illustrating the value of solid-state NMR in characterizing two polymorphs of curcumin will be discussed (e.g., see:  M.A. Matlinska, R.E. Wasylishen, G.M. Bernard, V.V, Terskikh, A. Brinkmann and V.K. Michaelis, Crystal Growth & Design, 2018, DOI: 10.1021/acs.cgd.8b00859).  Our experimental data is supplemented by plane-wave density functional theory (DFT) computations.