Chiral smectogens

Note 1 When the type of mesophase formed is known, more precisely qualifying terminology can be used, e.g., nematogen, smectogen and chiral nematogen. 

Unsymmetrically 1,1 -disubstituted ferrocenes 43 ( = 11-16) were synthesized by combining the organic substituents used to prepare 41 (n) and 42 ( ). Introduction of dissymmetry had two effects on the thermal and mesomorphic properties. First, a depression in the melting points was observed. Second, the smectogenic character of the materials was enhanced. Indeed, with the exception of 43 ( = 11), which showed only a SmA phase, all the members of the series showed both SmC and SmA phases. In view of the mesomorphic properties obtained for 43 ( ) in comparison with those of 41 ( ) and 42 ( ), one can anticipate that the combination of very different substituents (e.g., chiral with non-chiral moieties, hydrocarbon with fluorocarbon motifs) should lead to ferrocenes showing rich mesomorphism. 

One family of optically active mesophases, the smectogenous carbobis(N-L-a-amino acid esters) (see above), have been found to show chiral differentiation [26]... 

Piecek, W. Glab, K. L. Januszko, A. Perkowski, P. Kaszynski, P. Modihcation of electro-optical properties of an orthoconic chiral biphenyl smectogen with its isostructural carborane analogue, J. Mater. Chem. 2009,19, 1173-1182. 

C1/C2 chevrons, ferroelectric devices 644 cadmium selenium TFT address 233 Cano wedge, chiral nematics 347 f, 351 Canon technology, ferroelectric devices 648 capillaiy flow, shear viscosity 143 carbocyclic compounds, charge transfer systems 958 carbocyclic rings, smectogens 412 carbon atoms, intercalated smectics 808 carbon-carbon bonds, dimers 823 carbon-carbon double bonds, chiral smectics 498 carbonaceous phases 693 carbonyl connectors, antiferroelectrics 687 carbonyl groups... 

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