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Center for Nonlinear Studies |
In this talk, I will discuss our theoretical work on examining the intricate and complex nature of hydrophobic effects in a wide variety of hydrogen bonded systems. I will begin be re-visiting a classical problem in hydrophobicity namely the thermodynamics of cavity formation in bulk water. In particular, I will discuss the role of short-length scale natural density fluctuations emerging from the presence of asymmetric and non-spherical voids/cavities in the hydrogen bond network. The thermodynamic properties of the formation of these non-spherical voids is quite different from that of spheres and is likely to be important in understanding solvation of realistic small molecules that are branched and have molecular roughness. I will then move to discussing recent work on understanding the anomalous optical properties of amyloid proteins. Recent experiments suggest that these proteins can fluoresce in the absence of aromatic residues. The fluorescence is very sensitive to pH and isotope effects. Our simulations show that protons in the amyloids are quite labile and characterized by significant quantum effects. This has a significant impact on the optical properties of the system and gives as clues into the origins of the fluorescence. Finally, in the last part of my talk, I will share some insights into understanding the Janus-like character of the hydroxide ion in a water cluster which can be mapped to particular features of its Infra-Red spectra"
Host: Angel E. Garcia