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Twiston vs. random fluctuation as the source of the rapid motion of polyethylene in the inclusion complex with perhydrotriphenylene
Author(s) -
Zhan Yongjian,
Mattice Wayne L.
Publication year - 1993
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19930650117
Subject(s) - molecule , motion (physics) , atom (system on chip) , crystallography , chain (unit) , physics , polyethylene , inclusion (mineral) , chemistry , uncorrelated , molecular physics , mathematics , thermodynamics , classical mechanics , statistics , quantum mechanics , organic chemistry , computer science , embedded system
Recently molecular dynamics simulations were performed for polyethylene in the inclusion complex with perhydrotriphenylene. The system contained ninety molecules of perhydrotriphenylene, arranged in six stacks of fifteen molecules each, and one molecule of n ‐tetracontane, C 40 H 82 . The internal CH 2 ‐CH 2 bonds in n ‐tetracontane have a very strong preference for the trans state. Nevertheless, the chain exhibits a high degree of internal flexibility. This motion produces a characteristic pattern in δ|ψ N + i ψi | vs. N , where ψ i describes the instantaneous angle of a C‐H bond vector at carbon atom i about the axis defined by the channel, and δ denotes the fluctuation. The pattern expected for δ|ψ N + i ψi | vs. N is derived for the case where the rapid internal motion is produced by a twiston. It is compared with the results from the simulation and from the expectation for the case where the rapid motion arises from uncorrelated internal fluctuations within the trans state at each CH 2 ‐CH 2 bond.