Phases and phase changes in clusters of tert-butyl thiol
1997; Elsevier BV; Volume: 413-414; Linguagem: Inglês
10.1016/s0022-2860(97)00002-1
ISSN1872-8014
AutoresJames W. Hovick, Lawrence S. Bartell,
Tópico(s)Crystallography and molecular interactions
ResumoAbstract Clusters of tert-butyl thiol (TBT) were generated by condensation of vapor in supersonic flow under various expansion conditions, and their structures were examined during their free flight by electron diffraction. The system had been selected because of its similarity to tert-butyl chloride (TBC), a much more thoroughly studied material with an interesting solid-state chemistry. The warmest crystalline phase of TBT observed for the clusters (diameter, ≈ 130 A ) was the known high-temperature cubic phase I with a lattice constant of 8.609(5) A at ≈ 160 K. A second phase into which phase I nucleated at a rate of ≈ 1028 m−3 s−1 at about 157 K was also observed, as well as a third phase generated under conditions of very cold flow. All of the phases gave the rapidly damped, diffuse diffraction patterns characteristic of submicroscopic, poorly ordered, plastically crystalline materials. Patterns were far less distinct than those of TBC, and the structures of the colder two phases could not be determined. From the rapid nucleation rate of phase I into the second phase, it could be inferred that a major translational rearrangement of the molecules could not have been involved.
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