Chemical Control Of Heat Transport And Vibrational Energy Redistribution In Molecules

Controlling heat flow is an important goal for materials, for example, to thermally insulate components or, conversely, to allow heat to rapidly dissipate. One area where this is technologically relevant is the microelectronics industry where computer chips are limited both by the challenges of miniaturization but also thermal management. At the same time, chemical control of heat transport is not part of traditional chemistry, where there has been much more focus on the electronic processes involved in making and breaking chemical bonds, so we cannot rely on established chemical knowledge to design new thermal management materials. Today, we need new methods and understanding to broaden our chemical intuition for thermal transport properties of molecules.<br/>In this talk I will outline our efforts to develop chemical intuition for how we can control heat transport in molecules. While our understanding is far from complete, we can outline some general principles. Structural disorder in flexible systems, perhaps unsurprisingly, results in vibrational mode localization and reduced heat transport. While one might expect that breaking chemical bonds to yield non-bonded, self-assembled systems, would reduce heat transport it can also increase heat transport in certain cases. Finally, mass-disorder, for example from by changing to an inorganic complex instead of an organic molecule can be very effective at suppressing heat transport. Less clear are the effects of changing the structure of an organic molecule, for example between conjugated and saturated systems, leaving open a broad area of uncertainty as to ideal systems.