The $700,000 award will enable members from the Mittleman and Ruggiero groups to work together on a dual-experimental and theoretical front to pinpoint particular terahertz motions that dictate the properties of this important class of materials. Organic clathrates are found all over the planet, with a very large portion of methane gas trapped within ice clathrates in the Arctic regions. This award builds on years of sustained collaboration between the two groups, and will allow for pushing the boundaries of modern experimental and computational techniques. The project will also serve to train students from both institutions in two important (and complementary) areas of the chemical sciences, and through outreach efforts with local high school students this project will help expand the reach of federally-funded research beyond the two campuses.

The Faculty Early Career Development (CAREER) Program is a Foundation-wide activity that offers the National Science Foundation’s most prestigious awards in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.

In this work, Peter and Mark worked on understanding how to use low-frequency vibrational spectroscopy, coupled with anharmonic solid-state density functional theory simulations, to extract the interatomic forces in a pair of organic semiconductor crystals. They then used these forces to determine the thermoelastic response, i.e., the materials’ elastic response as a function of temperature, in a completely contactless and non-destructive manner. This represents an important advance in the field of materials chemistry, as traditional mechanical measurements require challenging and delicate sample preparation and complex experimental apparatus.

This work has an important impact for organic semiconductors in general, as these materials show great promise for use in flexible devices. The ‘flexible’ aspect requires a detailed understanding of the mechanical response of the material, in order to realize practical devices that operate as intended in real world applications.

This publication represents the culmination of two-years of undergraduate research for Mark Mancini, who worked under Prof. Adam Whalley before joining the Ruggiero Group. Mark was responsible for synthesizing and crystallizing the samples utilized in this study, as well as performing much of the characterization and calculations along with Peter. Mark was the recipient of the A. Paul Krapcho Chemistry Summer Fellowship, which was instrumental in this work.

Congratulations to everyone involved in this fantastic piece of work!

We will also make use of the recently installed tip-enhanced Raman spectrometer (TERS) to directly study the interaction of the organic with the surface of the minerals. This will not only aid in understanding the fundamental dynamics of these composite materials, but will have far-reaching implications in understanding how organic molecules interact with inorganic surfaces in general. This will provide insight and open doors into new research directions in the group, for example understanding the dynamics of surface sites used in catalysis.

We thank the generosity of the ACS PRF for this award, and look forward to all of the cool science we will be able to do.

The spectrometer is currently being developed and built by Horiba, one of the world leading instrument manufacturers. It includes a number of important capabilities that will complement the research of the Ruggiero Group, including an ultra-low frequency filter permitting spectral acquisitions from less than 5 cm^-1 to 9,000 cm^-1. Additionally, a conventional Raman confocal microscopy setup and a temperature controlled stage will enable the properties of advanced materials to be elucidated with unprecedented detail. The capabilities of the new instrument, coupled with the ongoing work being performed in the Ruggiero group, will make UVM one of the foremost institutions in the field of low-frequency vibrational spectroscopy. Mike and the rest of the group are very excited for the instrument installation, currently scheduled for late February, 2020.