Oligofluorene blue emitters for cholesteric liquid crystal lasers

Carbazole oligomers revisited: new additions at the carbazole 1- and 8-positions

“…As the carbazole core enlarges, from Cz-2 to Cz-5, the T g value augments, which is most likely due to the increased rigidity and a subsequent decrease in the free volume. The same trend is also observed for both linear oligofluorenes 12 and oligocarbazoles. 8 Of course, the T g can also be increased by decreasing the alkyl chain length at the N-position.…”

Development of Laser Dyes to Realize Low Threshold in Dye‐Doped Cholesteric Liquid Crystal Lasers

“…Syntheses of highly ordered dye molecules along the CLC local director have also been carried out successfully 13, 14. However, not much effort has been directed toward finding ideal dye systems 15, 16. Almost all the LC lasers so far investigated have utilized commercial laser dyes.…”

Strong main-chain length-dependence for the β-phase formation of oligofluorenes

“…4,5 A noteworthy structure of the main-chain conformation is the β-phase 1,3,6-9 that is formed by an expanded conjugation structure that shows red-shifted absorption and emission which enable many applications such as in organic lasers. [10][11][12] Regarding this feature, therefore, the chain-length dependence of the oligofluorenes is a crucial issue to clarify the inherent properties of fluorene polymers and oligomers and to design highly-functionalized fluorenebased materials. Several researchers have reported the synthesis of chain-length-controlled oligofluorenes 5,[13][14][15][16][17] and discussed the β-phase formation.…”