title: Enhanced emission and two-photon absorption cross-section by nanoaggregation of a cyano-substituted stilbene derivative.
abstract: This study reports the synthesis and the investigation of optical behaviors of a stilbene derivative, (Z)-2,3-bis[4-(N-4-(diphenylamino)styryl)phenyl]acrylonitrile (StCN). The nanoaggregates of StCN in 50% water/DMF have exhibit an increased fluorescence intensity and a blue shift with emission maximum wavelength with respect to StCN in 100% N, N-dimethylformamide (DMF) solution. This fluorescence enhancement can be attributed to the formation of J-aggregates. The cyano group prevents coplanarization of both arms and intermolecular face-to-face orientation leading to the formation of J-aggregates preventing the solvent relaxation. A strong fluorescence bathochromic solvatochromism is indicative of a large dipole moment in solution. Also, the two-photon absorption cross-section of nanoaggregates has been increased 1.5 times compared to that in DMF solution at the maximum wavelength.
authors.affiliation: Department of Advanced Materials, Hannam University, Daejeon 305-811, Korea.
authors.forename: Jin Sun
authors.initials: JS
authors.lastname: Park
authors.forename: Ran Hee
authors.initials: RH
authors.lastname: Kim
authors.forename: Nam Sung
authors.initials: NS
authors.lastname: Cho
authors.forename: Hong-Ku
authors.initials: HK
authors.lastname: Shim
authors.forename: Kwang-Sup
authors.initials: KS
authors.lastname: Lee
mesh_terms: D000042:Absorption; D002627:Chemistry, Physical; D004126:Dimethylformamide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D010777:Photochemistry / Q000379:methods*; D017785:Photons; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013267:Stilbenes / Q000737:chemistry*
chemical_list: D013267:Stilbenes; D004126:Dimethylformamide