title: High-pressure Raman spectroscopy of tris(hydroxymethyl)aminomethane.
abstract: High-pressure Raman spectroscopy has been used to study tris(hydroxymethyl)aminomethane (C(CH(2)OH)(3)NH(2), Tris). Molecules with globular shapes such as Tris have been studied thoroughly as a function of temperature and are of fundamental interest because of the presence of thermal transitions from orientational order to disorder. In contrast, relatively little is known about their high-pressure behavior. Diamond anvil cell techniques were used to generate pressures in Tris samples up to approximately 10 GPa. A phase transition was observed at a pressure of approximately 2 GPa that exhibited relatively slow kinetics and considerable hysteresis, indicative of a first-order transition. The Raman spectrum becomes significantly more complex in the high-pressure phase, indicating increased correlation splitting and significant enhancement in the intensity of some weak, low-pressure phase Raman-active modes.
authors.affiliation: Division of Materials Science, MS 388, University of Nevada, Reno, Reno, Nevada 89557, USA.
authors.forename: Erik D
authors.initials: ED
authors.lastname: Emmons
authors.forename: Juan C
authors.initials: JC
authors.lastname: Fallas
authors.forename: Vamsi K
authors.initials: VK
authors.lastname: Kamisetty
authors.forename: Wen-Ming
authors.initials: WM
authors.lastname: Chien
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Covington
authors.forename: Raja S
authors.initials: RS
authors.lastname: Chellappa
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Gramsch
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Hemley
authors.forename: Dhanesh
authors.initials: D
authors.lastname: Chandra