title: Crystal chemistry of layered structures formed by linear rigid silyl-capped molecules.
abstract: The crystallization behavior of methylthio- or methylsulfonyl-containing spacer extended Z,Z-bis-ene-yne molecules capped with trimethylsilyl groups obtained by (tandem) thiophene ring fragmentation and of two non-spacer extended analogs were investigated. The rigid and linear molecules generally crystallized in layers whereby the flexibility of the layer interfaces formed by the silyl groups leads to a remarkably rich crystal chemistry. The molecules with benzene and thiophene spacers both crystallized with C2/c symmetry and can be considered as merotypes. Increasing the steric bulk of the core by introduction of ethylenedioxythiophene (EDOT) gave a structure incommensurately modulated in the [010] direction. Further increase of steric demand in the case of a dimethoxythiophene restored periodicity along [010] but resulted in a doubling of the c vector. Two different polytypes were observed, which feature geometrically different layer interfaces (non-OD, order-disorder, polytypes), one with a high stacking fault probability. Oxidation of the methylthio groups of the benzene-based molecule to methylsulfonyl groups led to three polymorphs (two temperature-dependent), which were analyzed by Hirshfeld surface d e/d i fingerprint plots. The analogously oxidized EDOT-based molecule crystallized as systematic twins owing to its OD polytypism. Shortening of the backbone by removal of the aryl core resulted in an enantiomorphic structure and a further shortening by removal of a methylthio-ene fragment again in a systematically twinned OD polytype.
authors: Institute of Applied Synthetic Chemistry, Vienna University of Technology, Vienna, Austria.
authors: Daniel
authors: D
authors: Lumpi
authors: Institute of Applied Synthetic Chemistry, Vienna University of Technology, Vienna, Austria.
authors: Paul
authors: P
authors: Kautny
authors: Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria.
authors: Berthold
authors: B
authors: Stöger
authors: Institute of Applied Synthetic Chemistry, Vienna University of Technology, Vienna, Austria.
authors: Johannes
authors: J
authors: Fröhlich
keywords: Hirshfeld surface fingerprint plots; arene spacers; incommensurately modulated structures; layer interfaces; order–disorder polytypes