One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

• Roman Yu. Peshkov,
• Elena V. Panteleeva,
• Wang Chunyan,
• Evgeny V. Tretyakov and
• Vitalij D. Shteingarts

Beilstein J. Org. Chem. 2016, 12, 1577–1584, doi:10.3762/bjoc.12.153

• being used as components of liquid crystal mixtures [3][4][5][6][7][8], lubricants [9], media for conformational analysis using NMR [10][11][12] and EPR [13] techniques, and nanoparticles-doped liquid crystals [14]. The classic multistage approaches to these compounds, including successive biphenyl

Regiodefined synthesis of brominated hydroxyanthraquinones related to proisocrinins

• Joyeeta Roy,
• Tanushree Mal,
• Supriti Jana and
• Dipakranjan Mal

Beilstein J. Org. Chem. 2016, 12, 531–536, doi:10.3762/bjoc.12.52

• cytotoxic properties [6][7][8][9][10][11]. Anthraquinones are well-known as colorants in foods, drugs, and textile industries. They are also used as chemical sensors and liquid crystals [1][2][3][4][5]. Halogenated anthraquinones form a minor group of natural pigments [12][13][14][15]. 7-Bromoemodic acid (1

Self and directed assembly: people and molecules

• Tony D. James

Beilstein J. Org. Chem. 2016, 12, 391–405, doi:10.3762/bjoc.12.42

• colour of liquid crystals to determine chirality and was quickly prepared in just two steps. The addition of our D-glucose boronate complex to a liquid crystal system the colour changed from green to red, however for the L-glucose system the colour changed from green to blue [11][12] (Figure 2 depicting

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• ] and dendrimers [64][65] – work that ultimately led Cyrus Anderson, Darrell Kuykendall, Ying Li, Taiho Park, Kwansima Quansah, and Mauricio Suarez to a broader range of supramolecular polymers, including liquid crystals [66], network blends [67], alternating copolymers [68], reversible adhesives [69

Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations

• Giuseppina Raffaini,
• Antonino Mazzaglia and
• Fabio Ganazzoli

Beilstein J. Org. Chem. 2015, 11, 2459–2473, doi:10.3762/bjoc.11.267

• concentration and on the solvent) and by their shape, which may preferentially determine stable mesophases, ranging from micelles to membranes, or even liquid crystals. It is well-known that the shape and the interactions among native or modified cyclodextrins can drive specific packing in the solid state, but

An efficient synthesis of N-substituted 3-nitrothiophen-2-amines

• Sundaravel Vivek Kumar,
• Shanmugam Muthusubramanian,
• J. Carlos Menéndez and
• Subbu Perumal

Beilstein J. Org. Chem. 2015, 11, 1707–1712, doi:10.3762/bjoc.11.185

• -aminothiophenes have potential applications in the field of functional materials such as liquid crystals [13], nonlinear optical materials (NLOs) [14], organic solar cells [15], photonic polymers [16] and electroluminescent materials [17]. Nitrothiophenes are also important as chemotherapeutic agents and in a few

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

• Mahabaleshwara Subrao,
• Dakshina Murthy Potukuchi,
• Girish Sharada Ramachandra,
• Poornima Bhagavath,
• Sangeetha G. Bhat and
• Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• hydrotropic salts and phenols to microemulsions can lead to positive viscosity builds in both water-in-oil and water-in-carbon dioxide systems as observed by Eastoe et al. and John et al. [40][94][104] Emerging areas using supercritical CO2 Bicontinuous and lamellar phases, lamellar liquid crystals and foams

The influence of intraannular templates on the liquid crystallinity of shape-persistent macrocycles

• Joscha Vollmeyer,
• Ute Baumeister and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 910–920, doi:10.3762/bjoc.10.89

• planar. Keywords: discotic liquid crystals; shape-persistent macrocycles; templates; X-ray scattering; Introduction The supramolecular chemistry of shape-persistent macrocycles has enormously expanded during the past several years [1][2][3][4][5][6]. It covers the non-covalent interaction between the

• naphthylene corners allow an efficient surrounding of the macrocycles with an alkyl fringe, according to the general design principle for discotic liquid crystals [47]. In addition to the macrocycles with intraannular bridges, we also synthesized and investigated a corresponding compound with an empty

• transition of liquid crystalline dimers and bent-core liquid crystals which has recently been identified as a nematic–twist bent nematic (NTB) transition (see, e.g., [59][60]). Therefore the nature of the phase change indicated by the DSC measurements could not be clarified yet. The X-ray pattern for the

Unusual polymorphism in new bent-shaped liquid crystals based on biphenyl as a central molecular core

• Anna Kovářová,
• Svatopluk Světlík,
• Václav Kozmík,
• Jiří Svoboda,
• Vladimíra Novotná,
• Damian Pociecha,
• Ewa Gorecka and
• Natalia Podoliak

Beilstein J. Org. Chem. 2014, 10, 794–807, doi:10.3762/bjoc.10.75

• dielectric measurements. The dielectric spectroscopy data are unique and presented for the first time in the SmCG phase providing new information about the molecular dynamics. Keywords: bent-shaped; biphenyl core; liquid crystals; mesomorphic behaviour; SmCG phase; Introduction Achiral bent-shaped liquid

• ], semifluorinated alkyl chains [14][20], and fullerene [21] into the terminal chain(s), variation of the linkage groups [10][22][23][24] (ester, azo, azoxy, imine, H-bond, cinnamoyl). Also dimeric, dendritic, and polymeric liquid crystals possessing the biphenyl moiety in the centre of the bent mesogenic unit were

• series of materials IV–VI, we utilized lengthening arms of phenols 7a–c and two-ring acids 8–10. All intermediates were obtained previously by known methods [47][48][49]. The bent-shaped liquid crystals I–III were synthesized in three steps (Scheme 1). The protected acids 1a,b were esterified with

Triphenylene discotic liquid crystal trimers synthesized by Co₂(CO)₈-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition

• Bin Han,
• Ping Hu,
• Bi-Qin Wang,
• Carl Redshaw and
• Ke-Qing Zhao

Beilstein J. Org. Chem. 2013, 9, 2852–2861, doi:10.3762/bjoc.9.321

• mesomorphism. Keywords: Co2(CO)8 catalyzed cycloaddition; columnar mesophase; discotic liquid crystal; triphenylene; oligomer; Introduction Discotic liquid crystals (DLCs) with nematic phase have been commercially utilized in the liquid crystal display industry as optical compensating films for widening the

Synthesis of guanidinium–sulfonimide ion pairs: towards novel ionic liquid crystals

• Martin Butschies,
• Manuel M. Neidhardt,
• Markus Mansueto,
• Sabine Laschat and
• Stefan Tussetschläger

Beilstein J. Org. Chem. 2013, 9, 1093–1101, doi:10.3762/bjoc.9.121

• Martin Butschies Manuel M. Neidhardt Markus Mansueto Sabine Laschat Stefan Tussetschlager Institut für Organische Chemie, Universität Stuttgart, Pfaffenwalring 55, 70569 Stuttgart, Germany 10.3762/bjoc.9.121 Abstract The recently introduced concept of ionic liquid crystals (ILCs) with

• sulfonimide anion directly attached to the mesogenic unit. Keywords: anion exchange; ionic liquid crystals; ion pairs; mesophases; sulfonimides; Introduction While ionic liquids, i.e., molten salts composed of either organic cation or anion (or both) with melting points far below 100 °C, are extensively

Synthesis and structure of trans-bis(1,4-dimesityl-3-methyl-1,2,3-triazol-5-ylidene)palladium(II) dichloride and diacetate. Suzuki–Miyaura coupling of polybromoarenes with high catalytic turnover efficiencies

• Jeelani Basha Shaik,
• Venkatachalam Ramkumar,
• Babu Varghese and
• Sethuraman Sankararaman

Beilstein J. Org. Chem. 2013, 9, 698–704, doi:10.3762/bjoc.9.79

• find application in the areas of molecular electronics, organic discotic liquid crystals and OLEDs [24][25]. One of the ways to approach the synthesis of these interesting compounds is to carry out multiple C–C coupling reactions with suitable polybromoarene derivatives. In multiple C–C coupling

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

A new family of four-ring bent-core nematic liquid crystals with highly polar transverse and end groups

• Kalpana Upadhyaya,
• Venkatesh Gude,
• Golam Mohiuddin and
• Rao V. S. Nandiraju

Beilstein J. Org. Chem. 2013, 9, 26–35, doi:10.3762/bjoc.9.4

• -core mesogens; cyanobiphenyl; dipole moment; liquid crystals; nematic phase; polarity; Introduction Following the discovery of chiral and polar properties of mesomorphic bent-core compounds [1][2][3][4][5][6] the area of design, synthesis and properties of banana or bent-shaped liquid crystals (LC

• ~1606 cm−1, C=C stretching of an aromatic ring 1490 cm−1 and C–O–C stretching of an ester at ~1290 and ~1170 cm−1. The importance of the resorcylidene aniline core, present in calamitic ferroelectric liquid crystals [49][50][51][52][53], apparently seems superior to that of the benzylidene aniline core

Efficient electroorganic synthesis of 2,3,6,7,10,11-hexahydroxytriphenylene derivatives

• Carolin Regenbrecht and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2012, 8, 1721–1724, doi:10.3762/bjoc.8.196

• common structural motif. The use of triphenylenes in discotic liquid crystals [1][2] as building blocks in supramolecular chemistry [3][4] as well as in solid-state chemistry [5] is well documented. Furthermore, triphenylenes are applied as components of functional polymers [6][7] and fluorescent labels

Formation of smectic phases in binary liquid crystal mixtures with a huge length ratio

• Nadia Kapernaum,
• Friederike Knecht,
• C. Scott Hartley,
• Jeffrey C. Roberts,
• Robert P. Lemieux and
• Frank Giesselmann

Beilstein J. Org. Chem. 2012, 8, 1118–1125, doi:10.3762/bjoc.8.124

• phase of the longer mesogen was identified as a smectic F phase. Keywords: bidispersity; liquid crystals; phase diagrams; smectic phases; smectic F phase; structure and dynamics; Introduction The mixing of different liquid crystals is a common technique to tailor their properties for specific

Control over molecular motion using the cis–trans photoisomerization of the azo group

• Estíbaliz Merino and
• María Ribagorda

Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119

• conformational changes in polymers. There may also be variations in the organization of large assemblies of molecules in gels or liquid crystals. When polarized light is used, the photoisomerization often induces a reorganization of chromophores that can be reflected in the circular dichroism spectra. The basic

• photoswitch is a part of a macromolecular structure. A variety of photosensitive devices, such as smart polymers [36][37], liquid crystals [38][39], intelligent enzymes [40], and various switches and molecular machines [41][42][43][44][45][46][47][48], have been developed by using the photochromic properties

meta-Oligoazobiphenyls – synthesis via site-selective Mills reaction and photochemical properties

• Raphael Reuter and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2012, 8, 877–883, doi:10.3762/bjoc.8.99

• reduction of ~3.5 nm rendering it an ideal candidate for changing spatial arrangements on the molecular level. This change has been featured in a variety of applications [7][8][9], such as, switchable sensors [10], ion channels [11], catalysts [12], or liquid crystals [13]. In most of these applications

Synthesis of 2,6-disubstituted tetrahydroazulene derivatives

• Zakir Hussain,
• Henning Hopf,
• Khurshid Ayub and
• S. Holger Eichhorn

Beilstein J. Org. Chem. 2012, 8, 693–698, doi:10.3762/bjoc.8.77

• route by using carbene adduct intermediates. The protocol can be applied for the construction of functionalized hydroazulene skeletons as key components of many natural products as well as the core system of novel liquid-crystalline materials. Keywords: carbene addition; hydroazulenes; liquid crystals

Liquid-crystalline heterodimesogens and ABA-heterotrimesogens comprising a bent 3,5-diphenyl-1,2,4-oxadiazole central unit

• Govindaswamy Shanker,
• Marko Prehm and
• Carsten Tschierske

Beilstein J. Org. Chem. 2012, 8, 472–485, doi:10.3762/bjoc.8.54

• bent-core mesogens are of special interest for achieving biaxial nematic phases of the orthorhombic type. The orthogonal (NcybA) and skewed (NcybC) cybotactic nematic phases were distinguished by XRD and optical observations. Keywords: bent-core mesogens; cybotactic nematic phases; dimesogen; liquid

• crystals; 1,2,4-oxadiazoles; trimesogen; Introduction Liquid-crystalline (LC) dimers of low-molar-mass compounds formed by the coupling of two mesogenic segments are of contemporary interest [1][2][3][4]. These compounds exhibit fascinating properties, often different from the single mesogens, and they

Perhydroazulene-based liquid-crystalline materials with smectic phases

• Zakir Hussain,
• Henning Hopf and
• S. Holger Eichhorn

Beilstein J. Org. Chem. 2012, 8, 403–410, doi:10.3762/bjoc.8.44

• narrow temperature ranges. The dependence of the mesogenic behavior of the new materials on the stereochemistry of the core system was also investigated. All newly synthesized compounds were fully characterized by the usual spectroscopic and analytical methods. Keywords: hydroazulenes; liquid crystals

• ; nematic phases; smectic phases; Introduction Liquid crystals for display applications have to fulfill a complex, interdependent set of properties [1]. First of all, they must display a broad nematic phase, typically ranging from −30 °C to +80 °C. The absolute value for the dielectric anisotropy Δε should

• molecular design of new liquid crystals, electro-optical properties can now be predicted quite precisely based on molecular modeling [1][2]. However, full evaluation of the value of a new structure is still only possible after synthesis. In the past few years many attempts have been made to improve the

Synthesis and mesomorphic properties of calamitic malonates and cyanoacetates tethered to 4-cyanobiphenyls

• Katharina C. Kress,
• Martin Kaller,
• Kirill V. Axenov,
• Stefan Tussetschläger and
• Sabine Laschat

Beilstein J. Org. Chem. 2012, 8, 371–378, doi:10.3762/bjoc.8.40

• differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction (WAXS). Keywords: cyanoacetates; 4-cyanobiphenyls; liquid crystals; malonates; nematic; Introduction Nematic liquid crystals display mesophases in which the molecules are oriented along one vector defined by the director

• axis, but with the molecular arrangement in random positional order [1]. Nematic phases typically display low viscosity [2][3][4]. Due to the long-range orientational order they reveal anisotropic properties. These features make nematic liquid crystals very attractive materials for electronics [5][6][7

• ][8], for the construction of liquid crystal displays [9][10][11], or as anisotropic conductors [12][13]. Over the past few decades, a huge variety of organic calamitic compounds, which form nematic liquid crystals, have been synthesized and investigated [1][14]. Bulkin et al. were the first to

Liquid-crystalline nanoparticles: Hybrid design and mesophase structures

• Gareth L. Nealon,
• Romain Greget,
• Cristina Dominguez,
• Zsuzsanna T. Nagy,
• Daniel Guillon,
• Jean-Louis Gallani and
• Bertrand Donnio

Beilstein J. Org. Chem. 2012, 8, 349–370, doi:10.3762/bjoc.8.39

• background of liquid crystals is beyond the scope of this review, and the interested reader is directed to numerous texts on the subject [25][26][27][28][29]. The liquid-crystalline state is intermediate between that of a perfectly ordered crystal and a disordered isotropic liquid. The moieties within a

• presence of a solvent are known as lyotropic. A material that exhibits LC properties is referred to as a mesogen and is said to exhibit mesomorphism; although something that is mesogenic (e.g., proto-mesogens) is not necessarily mesomorphic. Thermotropic liquid crystals are usually formed by molecules that

• triphenylene discotic liquid crystals without disruption of the nature of the mesophase. Furthermore, thin films of Au@236,6 displayed 2-D hexagonal ordering on TEM grids, with interparticle distances less than twice the length of the organic moieties suggesting that the ligands at the surface were

Progress in liquid crystal chemistry II

• Sabine Laschat

Beilstein J. Org. Chem. 2012, 8, 118–119, doi:10.3762/bjoc.8.13

• liquid crystals? Liquid crystals have a major impact on our modern society, reaching from simple digital calculators to high-resolution flat-panel displays, and their market volume is expected to further increase. For example, in 2010 revenues of €1,013 million from sales of liquid crystals were reported

• , the chemistry behind liquid crystals, and particularly the synthesis, is the platform for such tremendous technological achievements, and this is true for both calamitic (rod-like) as well as discotic (disk-shaped) or other types of liquid crystals [2][3][4]. Since our initial Thematic Series

• "Progress in liquid crystal chemistry" two years ago [5], the research field has further broadened and stretches currently from materials science, through energy conversion and storage, to life sciences. The interested reader might be directed to a very recent special issue of Liquid Crystals edited by John