Siamese twin mesogen

Note 2 A liquid-erystal dimer or mesogenic dimer is sometimes known as a twin mesogen. Use of the terms dimesogenic compounds and Siamese-twin mesogen for liquid-crystal dimer or mesogenic dimer is not recommended. 

H. Dehne, A. Roger, D. Demus, S. Diele, H. Ktesse, G. Pelzl, W. Weissflog, Sulphur ligated Siamese twin mesogens. Liq. Cryst. 6, 47-62 (1989)... 

Molecules of liquid crystals can be built from a variety of structural elements. For instance, in 1927 Vorlander synthesized the first liquid crystal twins, now called tail-to-tail twins. A Siamese twin mesogen is a compound in which two independently mesogenic parts are joined in a single molecule. While earlier twins were ligated by carbon-containing groups such as methylene, Dehne et aV have shown that sulfur, sulfinyl or sulfonyl groups can perform a similar role. Anatomy of MLCs from the point of view of possible structures was reviewed in detail by Demus. ... 

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