Grant: Research Tools and Instruments

Nuclear magnetic resonance (NMR) is the premier technique for characterization of molecular structure and dynamics. Solid-state NMR (SSNMR) is widely used for the study of organic, inorganic, and biological materials, and aids researchers in understanding the nature of the compounds they have synthesized or materials they have produced, as well as providing a means for rationally designing new synthetic and preparative methods. Most SSNMR experiments related to chemical synthesis and materials science are commonly conducted over a relatively narrow temperature range (e.g., -150 C to 250 C). Conversely, low-temperature (LT) experiments down to 20 K (i.e., -253 C) are rarely conducted by chemists, due to the expenses and technical difficulties associated with the design and operation of LT magic-angle spinning (MAS) probes.<br /> <br /> In this grant proposal, we are requesting funding for a <strong>Low-Temperature SSNMR Probe</strong> for our 400 MHz NMR spectrometer, which operates over a temperature range from 20 K to 525 K (-253 C to +252 C), and is only used for stationary (i.e., non-spinning) samples (this probe will be the first of its kind in the world).&nbsp; With the aid of specialized pulse sequences designed at the University of Windsor (that eliminate the need for MAS), this probe will allow us to study NMR nuclei from elements across the periodic table, including so-called &ldquo;low gamma&rdquo; nuclei, which have low NMR frequencies and are generally very unreceptive to the NMR experiment. We will be able to investigate molecular structures in materials from the perspective of nuclides not routinely (or ever) studied by SSNMR spectroscopy. Furthermore, we will be able to access new regimes of molecular motions and dynamics (associated with temperatures from 20 to 120 K) that cannot be accessed on most NMR probes. There are currently no other SSNMR probes in existence with this combination of LT capabilities, broadband frequency range, and double-resonance operation. This will give researchers at UWindsor a unique opportunity to study a plethora of chemical systems that have not been previously explored, and examine phenomena such as structures, hydrogen-bonding networks and low-energy dynamical motions in a new low-temperature regime (this includes nanoparticles, pharmaceuticals, biological molecules, molecular machines, catalysts and organic conductors).&nbsp; This unique LT SSNMR probe will create and enrich collaborations between researchers at UWindsor, around Canada and in the international community, and will serve to yield new insights into molecular structure and dynamics at LT, leading to design of new and better materials with a variety of technologically important functions.