title: Converting Nonliquid Crystals into Liquid Crystals by N-Methylation in the Central Linker of Triazine-Based Dendrimers.
abstract: Two triazine-based dendrimers were successfully prepared in 60-75% yields. These newly prepared dendrimers 2a and 2b containing the -NMe(CH2)2NMe- and the -NMe(CH2)4NMe- linkers between two G3 dendrons, respectively, exhibit columnar phases during the thermal process. However, the corresponding dendrimers 1a and 1b containing the -NH(CH2)2NH- and the -NH(CH2)4NH- linkers between two G3 dendrons, respectively, do not show any LC phases on thermal treatment. Computational investigations on molecular conformations reveal that N-methylation of the dendritic central linker leads dendrimers to possess more isomeric conformations and thus successfully converts non-LC dendrimers (1a and 1b) into LC dendrimers (2a and 2b).
authors.affiliation: Department of Applied Chemistry, National Chi Nan University , Puli, Nantou 545, Taiwan.
authors.forename: Meng-Jung
authors.initials: MJ
authors.lastname: Tsai
authors.affiliation: Department of Applied Chemistry, National Chi Nan University , Puli, Nantou 545, Taiwan.
authors.forename: Jei-Way
authors.initials: JW
authors.lastname: Hsieh
authors.affiliation: Department of Applied Chemistry, National Chi Nan University , Puli, Nantou 545, Taiwan.
authors.forename: Long-Li
authors.initials: LL
authors.lastname: Lai
authors.affiliation: Material and Chemical Research Laboratories Industrial Research Institute , Hsinchu 300, Taiwan.
authors.forename: Kung-Lung
authors.initials: KL
authors.lastname: Cheng
authors.affiliation: Material and Chemical Research Laboratories Industrial Research Institute , Hsinchu 300, Taiwan.
authors.forename: Shih-Hsien
authors.initials: SH
authors.lastname: Liu
authors.affiliation: National Synchrotron Radiation Research Center , HsinChu Science Park, Hsinchu 300, Taiwan.
authors.forename: Jey-Jau
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Tamkang University , Tamsui 251, Taiwan.
authors.forename: Hsiu-Fu
authors.initials: HF
authors.lastname: Hsu