Liquid crytals (LCs) are probably the most exciting state of matter. They attract scientists across disciplines such as chemistry, physics, materials science, and engineering—theorists and experimentalists alike. These days, you can buy quite affordable LCD TV sets around the corner, but that's just one of the many things liquid crystals can do. The selection of recent research articles presented below illustrates the broad interest in this area of soft condensed matter.
J. W. Goodby, P. J. Collings, T. Kato, C. Tschierske, H. Gleeson,
Handbook of Liquid Crystals
2nd edition, Wiley-VCH, Weinheim, 2014.
Find all articles on liquid crystals in Wiley Online Library...
See the International Liquid Crystal Society's website.
Helical nanofilaments twist in sync forming a dual modulated, homochiral helical nanofilament phase, but only when the constituent molecules are unichiral. Left-handed nanofilaments form a left-handed, right-handed nanofilaments a right-handed secondary twist. The two phases with opposite handedness do not mix by forming a chiral conglomerate, as their achiral molecular counterparts, but rather induce a short correlated crystalline ribbon phase.
Lin Li, Miroslaw Salamonczyk, Antal Jákli, Torsten Hegmann
Small, June 23, 2016, DOI: 10.1002/smll.201600882. Read article
A good promoter: A chiral amphiphile, which is a room-temperature ionic LC over a broad temperature range, was designed and prepared as a chiral promoter. The incorporation of the chiral amphiphile triggers achiral polyoxometalates in the complexes to show induced CD signals through intermolecular interactions. The electrostatic encapsulation with the promoter provides the inorganic PMs with LC behavior.
Jing Zhang, Jingfang Li, Hong Yuan, Guohua Zhang, Bao Li, Wen Li, Xuehong Wei, Xin-E Duan, Lixin Wu
Chem. Asian J., June 17, 2016, DOI: 10.1002/asia.201600532. Read article
: A hexadodecyl-substituted zinc phthalocyanine covalently linked through a flexible spacer to a fullerene - ZnPc-C60 - has been investigated regarding electron transfer from the photoexcited, electron donating ZnPc to the electron accepting C60.While ground state interactions between electron donor and acceptor within ZnPc-C60 could not be detected via steady state absorption spectroscopy, clear proof for excited state interactions came from steady state fluorescence spectroscopy. To this end, the fluorescence in ZnPc-C60 is strongly quenched with quantum yields in THF as low as 0.05.Insight into excited state electron transfer deactivation within ZnPc-C60 came from time resolved femtosecond transient absorption spectroscopy.For example, upon exclusive excitation of the phthalocyanine within the ZnPc-C60 conjugate, a set of transients evolve featuring, on one hand, the signature of the one-electron oxidized ZnPc radical cation and, on the other hand, of the one-electron reduced C60 radical anion.The analysis of the corresponding dynamics in chlorobenzene resulted in lifetimes for charge separation and charge recombination of 7.4 ps and 2.2 ns, respectively.
Marcus Lederer, Mine Ince, M. Victoria Martinez-Diaz, Dirk M. Guldi, Tomas Torres
ChemPlusChem, June 16, 2016, DOI: 10.1002/cplu.201600197. Read article
Polycatenar mesogens form columnar phases with the number of molecules in the column cross section. For some compounds, an electron density modulation along the columns is observed, which may lead to a new type of liquid crystal phase with three-dimensional positional order.
Joanna M. Wolska, Neha Topnani, Ewa Gorecka, Jozef Mieczkowski, Damian Pociecha
ChemPhysChem, June 15, 2016, DOI: 10.1002/cphc.201600330. Read article
Zwitterionic derivatives of the [closo-1-CB11H12]– anion form liquid-crystalline phases and improve the dielectric properties of nematic liquid-crystal materials.
Jacek Pecyna, Remigiusz Żurawiński, Piotr Kaszyński, Damian Pociecha, Piotr Zagórski, Serhii Pakhomov
Eur. J. Inorg. Chem., April 27, 2016, DOI: 10.1002/ejic.201600240. Read article.
Total recoil: A novel foldamer scaffold, in which p-phenyleneethynylene units are linked by chiral carbon atoms, is reported. In very dilute solutions, these oligomers are random coils. The hexamer and octamers form a hexagonal lyotropic liquid crystal in CH2Cl2 when the concentrations reach the critical values.
Yu Chen, Zhiqiang Zhao, Zheng Bian, Rizhe Jin, Chuanqing Kang, Xuepeng Qiu, Haiquan Guo, Zhijun Du, Lianxun Gao
ChemistryOpen, April 27, 2016, DOI: 10.1002/open.201600007. Read article
Versatile Suzuki cross-coupling reactions between arylboronic acids and triphenylenyl triflates generate a rich diversity of attractive functional discogens.
Ke-Qing Zhao, Yue Gao, Wen-Hao Yu, Ping Hu, Bi-Qin Wang, Benoît Heinrich, Bertrand Donnio
Eur. J. Org. Chem., April 13, 2016, DOI: 10.1002/ejoc.201600270. Read article.
A simple modular design was used to impart liquid-crystalline properties to iridium complexes without modification of their photophysical properties. Annealed films of the liquid-crystalline complexes display hole mobilities up to three orders of magnitude higher than parent iridium complex without mesogenic groups and are the highest values reported to date for iridium complexes (see figure).
Yafei Wang, Christopher P. Cabry, ManJun Xiao, Louise Male, Stephen J. Cowling, Duncan W. Bruce, Junwei Shi, Weiguo Zhu, Etienne Baranoff
Chem. Eur. J., December 22, 2015, DOI: 10.1002/chem.201504669. Read article.
Changing states: The cohesive free energy density concept (CFED) is applied to thermotropic cyanobiphenyl-based liquid crystals to establish predictive quantitative correlations between each antagonist segments of the amphiphilic molecules (flexible alkyl tail/rigid aromatic core) and their transition temperatures (solid→liquid crystalline/liquid crystalline→ isotropic liquid; see figure).
Thibault Dutronc, Emmanuel Terazzi, Laure Guénée, Kerry-Lee Buchwalder, Sébastien Floquet, Claude Piguet
Chem. Eur. J., December 14, 2015, DOI: 10.1002/chem.201503420. Read article.