3,5-Dialkoxy Substituted Triphenyl-tristriazolotriazines: Fluorescent Discotic Liquid Crystals

Rieth, Thorsten; Glang, Stefan; Borchmann, Dorothee E.; Detert, Heiner

doi:10.1080/15421406.2015.1025210

Cited by 13 publications

(13 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on the data observed in Table 2 and Figure 5, three linear peripheral chains, as described for EST‐4 and TTT‐4 (3d), [4] are a small number of chains to stabilize a mesomorphism, regardless of the size of the aromatic core. For products with six chains, arranged in positions 3 and 5, the expanded product EST‐35 showed no mesomorphism, remaining in an amorphous state after the first heating, while TTT‐35 (15) [7a] showed Col h mesophase. Apparently, with this specific chains arrangement, a more compact aromatic core proved to be more favourable.…”

Section: Resultsmentioning

confidence: 99%

Reaching Room‐Temperature Mesomorphism through Expansion of the Tristriazolotriazine Core with Alkoxybenzoate Units

et al. 2022

View full text Add to dashboard Cite

The tristriazolotriazine (TTT) N‐heterocycle, despite being a relatively new mesogenic core for use in discotic liquid crystals, has already demonstrated its importance and promising characteristics. In this work, we extended the knowledge about the TTT, increasing the core size with alkoxybenzoate units, as well as evaluating how the expansion and number of peripheral chains affected the thermal and photophysical properties, both in solution and spin‐coated films. Their thermal behaviour and self‐assembly were studied by differential scanning calorimetry, polarizing optical microscopy and X‐ray diffraction with synchrotron radiation, while the photophysics was investigated by UV‐Vis absorption and fluorescence spectroscopy. The results show that, despite a considerable decrease in the fluorescence quantum yield with the core expansion, the mesomorphic properties are significantly enhanced, with two products showing Colh mesophase at room temperature, with large range of mesomorphism and very good thermal stability. It was also demonstrated how structural changes affected the self‐assembly properties.

show abstract

Section: Resultsmentioning

confidence: 99%

Reaching Room‐Temperature Mesomorphism through Expansion of the Tristriazolotriazine Core with Alkoxybenzoate Units

et al. 2022

View full text Add to dashboard Cite

show abstract

“…A study of the correlation between chain length and transition temperatures [24] on 3,5-dialkoxyphenyl t-TTTs (24)(25)(26)(27)(28) shows an asymptotic decrease of both transitions together with broadening of the mesophase from hexyl (24: Cr 136 m 187 I) to dodecyl (28: Cr 74 Col h 142 I). The 3,4,5 pattern is less influenced by chain length, both transitions are nearly constant for hexyl 39 to decyl 41(m.p.…”

Section: Mesomorphismmentioning

confidence: 99%

“…from log ε = 4.77 for 21 (octyl) to log ε = 4.23 for the 22 (dodecyl). [7,18,24] These compounds are negatively solvatochromic in their absorption but show positive solvatofluorism. [7] The emission of 16-21 in chloroform peaks at λ max = 362 nm.…”

Section: Optical Propertiesmentioning

confidence: 99%

“…X-ray diffraction on oriented fibers of 3,5-didodecyloxyphenyl-t-TTT 28 (Cr 74 Col h 143 I) in the mesophase [24] led to a hexagonal columnar arrangement with a = 30.8 Å. Careful evaluation of the diffraction pattern at 25°C and DSC revealed a superposition of two hexagonal lattices with a = 30.8 Å or a = 33.8 Å; the ratio strongly depends on the thermal history.…”

Section: Structures Of Mesophasesmentioning

confidence: 99%

See 1 more Smart Citation

Tristriazolotriazines: Luminescent Discotic Liquid Crystals

Detert

2018

Eur J Org Chem

Self Cite

View full text Add to dashboard Cite

Tristriazolotriazines (TTT) are new tetracyclic and planar cores for discotic liquid crystals. Two symmetrical isomers are known, paddle‐wheel type t‐TTTs and r‐TTTs with the shape of a propeller. Cyclocondensation of chlorotriazoles gives r‐TTTs, Huisgen reaction of tetrazoles and cyanuric chloride yields t‐TTTs with tangentially attached substituents. Many alkoxyphenyl‐substituted t‐TTTs form broad mesophases, typically with a hexagonal columnar structure. These luminescent molecules, when heated above 200 °C, suffer a thermal isomerization. A threefold ring opening/ring closing mechanism transforms t‐TTTs via unsymmetrical isomers to r‐TTTs. Thermotropic properties are largely influenced by planarization and increase of molecular diameter. Increased melting points, even the complete loss of liquid crystallinity have been observed, but also the gain of mesomorphism.

show abstract

“…Tristriazolotriazine (TTT) prepared according to the Huisgen route (Huisgen et al, 1960) is a new core for discotic liquid crystals (Cristiano et al, 2008;Glang et al, 2014;Rieth et al, , 2015. These compounds suffer a thermal isomerization (Rieth et al, 2018) of all annulated triazole moieties from the original 4,3-annulation to the 1,5-annulation, like in the title compound.…”

Section: Structure Descriptionmentioning

confidence: 99%