Static and dynamic molecular mechanics modelling and X-ray scattering calculations for a cyclic siloxane macromolecule

✍ Scribed by Pachter, Ruth ;Bunning, Timothy J. ;Crane, Robert L. ;Adams, W. Wade ;Socci, Edward P. ;Farmer, Barry L.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1993
• Weight: 722 KB
• Volume: 2
• Category: Article
• ISSN: 1018-5054
• DOI: 10.1002/mats.1993.040020304

✦ Synopsis

Abstract

A liquid crystalline system consisting of cyclic penta(methylsiloxane) cores with biphenylyl 4‐propoxybenzoate mesogens is studied with respect to its molecular conformation and the intermolecular ordering of pendant groups by employing molecular mechaincs calculations, while a molecular dynamics simulation indicates the degree of conformational flexibility. The calculated X‐ray scattering patterns for these structures provide insight into the origin of the experimentally observed results. A good agreement is found between the calculated and experimental reflections data, supporting the ‘cylinder’ global topology as the basis for forming a ‘columnar’ structure. Further, a comparison of the calculated and experimental meriodional sections shows a strong similarity of both the meridional intensities and d‐spacings.