Poly liquid-crystalline property

Thermotropic liquid crystalline (LC) phases or mesophases are usually formed by rod-like (calamitic) or disk-like (discotic) molecules. Spheroidal dendrimers are therefore incapable of forming mesophases unless they are flexible, because this would allow them to deform and subsequently line up in a common orientation. However, poly(ethyleneimine) dendrimers were reported to exhibit lyotropic liquid crystalline properties as early as 1988 [123],... 

An effort to combine the thermotropic liquid-crystalline properties of selected cellulose derivatives with the ion-conductive characteristics of poly(ethylene oxide) (PEO) has currently been pursued [234,235]. TPEO-CELL shown in Scheme 7 is a representative sample. 

A mixture of molybdenum hexacarbonyl and 4-chlorophenol is effective in performing al-kyne metathesis of dipropynylated dialkylbenzenes. Alkyne metathesis of these precursors leads to the clean formation of dialkyl poly( paraphenyleneethynylene)s (PPEs) in high yield and with high molecular weights. This facile yet effective access to the PPEs has allowed study of their spectroscopic, structural, and thermal properties. While PPEs have been made before, the dialkyl-PPEs turned out to have particularly interesting optical and liquid-crystalline properties that can be explained in terms of the conformation of the main chains. The PPEs have also been utilized to construct light-emitting diodes and other semiconductor devices. This chapter discusses the interplay of structure, chromicity, and electronic properties of the dialkyl-PPEs. 

Lyotropic liquid crystalline properties were observed for poly (arylamide) monodendrons derived from 1,3,5-substituted amino acid chloride hydrochlorides according to Kim [168]. These systems aggregate readily to form high molecular weight species in the absence of complexing ions. Amide solvents containing more than 40 wt.% of the dendrons exhibit nematic phase liquid crystalline texture under a polarizing microscope, whereas, 60 wt.% solutions produce a hard gel under static conditions. 

Liquid crystal polymers (LCPs) have been a source of considerable interest for some time, as they have been shown to offer particular advantages in terms of their processability and physical properties which make them attractive in a wide range of engineering applications.346 Serrano and his colleagues have reviewed metallomesogenic polymers, including the liquid crystalline properties of several of the platinum poly-yndiyl polymers described above.85,86... 

The synthesis and liquid crystalline properties are presented of two classes of chiral (I-n) and prochiral (Il-m) thermotropic poly(ester 0-sulfide)s. The nematic mesophase behavior of the polymers I-n exhibits distinct even-odd alternations with chemical structure and is compared with that of closely related poly(ester 0-sulfide)s Ill-n and IV-m. 

Kijima, M. Kinoshita, I. Hattori, T. Shirakawa, H. Poly(2,5-dialkoxy-/r-phenylenebutadiynylenejs. Novel rigid conjugated polymers with liquid crystalline property. Synth. Met. 1999, 70d(l), 61 69. 

We are now studying both the lyotropic and thermotropic liquid crystalline properties of poly(enamine-ketones). Also in progress is the synthesis of poly(enamine-ketones) derived from diaminoarenes, polymers containing all ring systems. We hope to obtain rod-like polymers with both lyotropic and thermotropic liquid crystalline properties that permit their processing into useful end products. 

Bao, Z.N., K.R. Amundson, and A.J. Lovinger. 1998. Poly(phenylenevinylene)S with dendritic side chains Synthesis, self-ordering, and liquid crystalline properties. Macromolecules 31 (24) 8647-8649. 

Liu G, Ding J, Qiao L, Guo A, Dymov BP, Gleeson JT, Saijo K (1999) Polystyrene-block-poly(2-cinnamoylethyl methacrylate) nanofibers— preparation, characterization, and liquid crystalline properties. Chem Eur J 5(9) 2740-2749. doi 10.1002/(SICl)1521-3765(19990903)5 9<2740 AID-CHEM2740>3.0.CO 2-V... 

S. Hernandez-Ainsa, R. Alcala, J. Barbera, M. Marcos, C. Sanchez, J.L. Serrano, Ionic azo-codendrimers influence of the acids contents in the liquid crystalline properties and the photoinduced optical anisotropy. Europ. Poly. J. 47, 311-318 (2011)... 

Capitani, D., De Frisco, N., Laurienzo, R, Malinconico, M., Proietti, N., Roviello, A. (2001), A new class of poly(ester hydrazide) copolymers with liquid crystalline properties Synthesis and characterization. Polymer Journal, 33, 575-83. 

Liu, G.J., Ding, J.F., Qiao, L.J., Guo, A., Dymov, B.P., Gleeson, J.T., Hashimoto, T., Saijo, K., 1999a. Polystyrene-block-poly (2-cinnamoylethyl methacrylate) nanofibers — preparation, characterization, and liquid crystalline properties. Chemistry-A European Journal 5, 2740-2749. 

Tian Y, Kamata K, Yoshida H, lyoda T (2006) Synthesis, liquid-crystalline properties, and supramolecular nanostructures of dendronized poly(isocyanide)s and their preciusors. Chem Eur J 12(2) 584-591. doi 10.1002/chem.200500868... 

Baars MWPL, Suntjens SHM, Fischer HM, Peerlings HWI, Meijer EW (1998) Liquid-crystalline properties of poly(propylene imine) dendrimers functionalized with cyanobiphenyl mesogens at the periphery. Chem Eur J 4 2456-2466... 

The liquid-crystalline properties of 20-25 clearly depend on the generation of each dendron. When the generation of the poly(benzyl ether) dendron is higher than that of the poly(aryl ester) dendron, columnar mesomorphism is observed (i.e., for 20-22) conversely, when the generation of the poly(aryl ester) dendron is higher (i.e., for 24) than or the same as (i.e., for 23 and 25) that of the poly(benzyl ether) dendron, smectic mesomorphism is observed. The hquid-crystalline properties of 20-25 can thus be tuned by design. 

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