title: Potassium ion induced changes of crystal structure and fluorescence of a crown ether.
abstract: Luminescence properties and the x-ray structures of the fluorescent crown ether, 16-anthracen-ylmethyl-1,4,7,10,13-pentaoxa-16-aza-cyclooctadecane (CEA) and its complex with potassium hexafluorophosphate (CEAK) have been obtained. In the solid state CEAK gives a structured blue emission and CEA gives a broad structureless green emission. The differences in luminescence behavior are explained on the basis of crystal packing. X-ray analysis shows that every two adjacent anthracene moieties in CEA form a sandwich-like anti-parallel dimer; the green-structureless emission then arises from the pi-pi stack of the aromatic rings. In CEAK, disruption of the pi-pi stacking structure forces a large separation between the anthracene rings, which yields an anthracene monomer emission. Luminescence lifetime data support the assignments.
authors: Department of Chemistry, University of Virginia, Charlottesville, VA 22904-4319, USA.
authors: Qiu-Xian
authors: QX
authors: Ren
authors: Vincent
authors: V
authors: Douglass
authors: Wenying
authors: W
authors: Xu
authors: Michal
authors: M
authors: Sabat
authors: A
authors: A
authors: Periasamy
authors: J N
authors: JN
authors: Demas
authors: B A
authors: BA
authors: DeGraff
mesh_terms: D043844:Crown Ethers / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005453:Fluorescence; D036641:Microscopy, Fluorescence, Multiphoton; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D011188:Potassium / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D043844:Crown Ethers; D011188:Potassium