title: An unusual stacking transformation in liquid-crystalline columnar assemblies of clicked molecular propellers with tunable light emissions.
abstract: The columnar liquid-crystalline (LC) and fluorescence properties of three-dimensional molecular propellers based on tetraphenylethylene is reported. X-ray scattering studies reveal an unusual transition from a rectangular (Colrec ) to a hexagonal columnar (Colhex ) phase. In contrast to second-order intercolumnar transitions based on a common tilt mechanism, the transition is first order and involves an unprecedented zigzag stacking of aromatic propellers in the Colrec phase. A sudden change in emission color from sky blue to green occurs rapidly and reversibly at this transition, which is due to the planarization of the propeller mesogen.
authors.affiliation: Department of Chemistry, Dankook University, Jukjeon 126, Gyeonggi, 448-701 (Korea), Fax: (+82) 31-8005-3153.
authors.forename: Jinhee
authors.initials: J
authors.lastname: Kim
authors.forename: Sung
authors.initials: S
authors.lastname: Cho
authors.forename: Byoung-Ki
authors.initials: BK
authors.lastname: Cho
keywords: click chemistry; fluorescence; liquid crystalline propeller; liquid crystals; propeller mesogen; thermochromism