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CPP: Chemische Physik und Polymerphysik

CPP 27: POSTER Polymer Physics and Materials

CPP 27.47: Poster

Thursday, March 30, 2006, 17:00–19:00, P2

Semi-flexible star-shaped molecules — •Sibylle Gemming^1,2, Michael Schreiber², Matthias Lehmann³, Igor Popov¹, and Gotthard Seifert¹ — ¹Physikalische Chemie und Elektrochemie, TU Dresden, D-01062 Dresden — ²Institut für Physik, Technische Universität, D-09107 Chemnitz — ³Institut für Chemie, Technische Universität, D-09107 Chemnitz

The structural prerequisites are investigated, which make star-shaped molecules suitable precursors for the formation of columnar liquid crystalline phases. Electronic structure calculations on smaller mesogens show, that not all conformers exhibit the atomistic structure, the stability against distortion, and additional dipole moments, which favour columnar stacking. For the presently studied compounds with short terminating alkyl chains, the calculations indicate that the steric factor becomes dominant with increasing star size. Thus, the optimised geometric structures were employed to generate a simplified mathematical model of the structures, which accounts only for the steric interaction in the larger stars. With the help of these diagrams, the most common conformers of star-shaped molecules can be derived in a systematic fashion.