The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy (Δe), which contains at least one compound selected from the group of compounds of the formula I, II A and II B and at least one compound of the formula I* in which R0, R1, R2, R1*, X1, X2, A1, A1*, A2*, Z1, Z1*, Z2*, L1*, L2*, p, q, v, m and m* are as defined in Claim 1, and to the use thereof for an active-matrix display based on the ECB, VA, PS-VA, FFS, PALC or IPS effect.

Liquid Crystalline Medium

Fluorescent H-aggregates of merocyanine dyes.

Liquid crystal (LC) media based on a mixture of polar compounds having negative dielectric anisotropy, their use in electro-optical displays, especially those having active matrix addressing based on the ECB (electrically controlled birefringence) or VA (vertically aligned) mode or similar modes, and LC displays of these types, are described.

Liquid crystal medium

A hair dye composition containing a triazene dissociative direct dye represented by general formula (1): A-N=N-NH-B (1) wherein A and B are each a monocyclic or a bicyclic aromatic heterocyclic group that may have a substituent or a monocyclic or a bicyclic aryl group that may have a substituent and contain none of a carboxy group, a sulfo group and a quaternary ammonium group; and A and B each bind to a triazene-1,3-diyl group represented by -N=N-NH- via a carbon atom within A and B each. A and B may be the same or different.

Hair-dye composition

Aggregation-induced emission (AIE) has attracted considerable interest over the last twenty years. In contrast to the large number of available reviews focusing specifically on AIE, this Essay discusses the AIE phenomenon from a broader perspective, with an emphasis on early observations related to AIE made long before the term was coined. Illustrative examples are highlighted from the 20th century where fluorescence enhancement upon rigidification of dyes in viscous or solid environments or J-aggregate formation was studied. It is shown that these examples already include typical AIE luminogens such as tetraphenylethylene (TPE) as well as stilbenes and oligo- or polyphenylenevinylenes and -ethynylenes, which became important fluorescent solid-state materials in OLED research in the 1990s. Further examples include cyanine dyes such as thiazole orange (TO) or its dimers (TOTOs), which have been widely applied as molecular probes in nucleic acid research. The up to 10 000-fold fluorescence enhancement of such dyes upon intercalation into double-stranded DNA, attributable to the restricted intramolecular motion (RIM) concept, afforded commercial products for bioimaging and fluorescence sensing applications already in the early 1990s.

Aggregation-Induced Emission (AIE): A Historical Perspective.

The invention concerns polymerizable liquid-crystalline compounds of the general formula (I) Z?1-Y1-A1-Y3-M-Y4-A2-Y2-Z2? in which the variables have the following meanings: Z1, Z2 are radicals with reactive groups which can bring about polymerization; Y1 - Y4 are a chemical single bond, oxygen, sulphur, -O-CO-, -CO-O-, -O-CO-O-, -CO-NR-, -NR-CO-, -O-CO-NR-, -NR-CO-O- or -NR-CO-NR-, at least one of the groups Y?3 and Y4? meaning -O-CO-O-, -O-CO-NR-, -NR-CO-O- or -NR-CO-NR-; A1, A2 are C?2?-C30 spacers in which the carbon chain can be interrupted by oxygen in the ether function, sulphur in the thioetherfunction or by non-adjacent imino or C1-C4 alkylimino groups; M is a mesogenic group; and R is C1-C4 alkyl. The compounds and compositions containing them are distinguished by advantageous liquid-crystalline phase temperature ranges and can be used in optical display units and cholesteric liquid-crystalline colouring agents.

Polymerizable liquid-crystalline compounds

The invention pertains to chiral compounds that contain at least one double or multiple bonded chiral group, at least one polymerizable group, at least one spacer and at least one mesogenic group, and to their use as polymerizable, chiral doping agents in the production of cholesteric networks. The compounds as per the invention can be used in electro-optical displays or as chiral doping agents for nematic or cholesteric liquid crystals to produce color-reflecting layers.

Polymerizable, chiral compounds and their use

Liquid crystal compounds have the general formula (I) Z-Y-A-Y-M-Y-A-Y-Z, in which the residues Z represent independently from each other a polymerisable group, the residues Y represent independently from each other a direct bond, O, S, COO, OCO, CONR or N(R)CO, the residues A represent independently from each other a spacer and M represents a mesogenic group. These compounds are for example useful for producing dyes in the form of cholesteric liquid crystals.

New polymerisable liquid crystal compounds

Polymerisierbare chirale Verbindungen der allgemeinen Formel I 
        (Z-Y 1 -A-O-CO-O-M-Y 2 ) n X      I 
in der die Variablen folgende Bedeutung haben
 A Spacer, M mesogene Gruppen Y 1 ,Y 2 chemische Bindungen oder die Gruppierungen -O-; -S-; -CO-O-; -O-CO-; -O-CO-O-; -CO-N(R)- oder -N(R)-CO- X ein n-wertiger chiraler Rest n 2 bis 6 Z a 1 ) mindestens einer dieser Reste eine reaktive Gruppe, uber die eine Polyaddition herbeigefuhrt werden kann, a 2 ) mindestens zwei dieser Reste Substituenten, die eine reaktive Gruppe tragen, uber welche eine Polykondensation herbeigefuhrt werden kann, b) Wasserstoff oder nicht-reaktive Reste, soweit die Bedingung (a 1 ) bzw. (a 2 ) erfullt ist, wobei die Reste Z, Y 1 , A, M und Y 2 , da sie n-mal in I enthalten sind, gleich oder verschieden sein konnen.
 Die erfindungsgemasen Verbindungen eignen sich zur Verwendung in elektro-optischen Anzeigen oder als chirale Dotierstoffe fur nematische oder cholesterische Flussigkristalle zur Erzeugung farbig reflektierender Schichten.

Polymerisierbare chirale Verbindungen und deren Verwendung

Polymerisierbare flussigkristalline Verbindungen der allgemeinen Formel (I): Z?1-Y1-A1-Y3-M-Y4-A2-Y2-Z2?, in der die Variablen folgende Bedeutung haben: Z1, Z2 Reste mit reaktiven Gruppen, uber die eine Polymerisation herbeigefuhrt werden kann, Y1 - Y4 chemische Einfachbindung, Sauerstoff, Schwefel, -O-CO-, -CO-O-, -O-CO-O-, -CO-NR-, -NR-CO-, -O-CO-NR-, -NR-CO-O- oder -NR-CO-NR-, wobei mindestens eine der Gruppen Y?3 und Y4? -O-CO-O-, -O-CO-NR-, -NR-CO-O oder -NR-CO-NR- bedeutet. A1, A2 Spacer mit 2 bis 30 C-Atomen, in welchen die Kohlenstoffkette durch Sauerstoff in Etherfunktion, Schwefel in Thioetherfunktion oder durch nichtbenachbarte Imino- oder C?1?-C4-Alkyliminogruppen unterbrochen sein kann, M eine mesogene Gruppe, R C1-C4-Alkyl. Die Verbindungen und Zusammensetzungen, welche diese enthalten, zeichnen sich durch gunstige flussigkristalline Phasentemperaturbereiche aus und konnen in optischen Anzeigegeraten und in cholesterisch flussigkristallinen Farbmitteln verwendet werden.

Karl-Heinz Dr Etzbach

Papers

Polymerizable liquid-crystalline compounds

Polymerizable, chiral compounds and their use

New polymerisable liquid crystal compounds

Polymerisierbare chirale Verbindungen und deren Verwendung

Neue polymerisierbare flüssigkristalline verbindungen