title: Two-photon excitation of dioxane: time-resolved measurements of excited state complex formation with water.
abstract: We observed emission from the non-aromatic hydrocarbon 1,4-dioxane upon illumination with ps pulses at 380 nm. The emission intensity depended quadratically on incident power at 380 nm, indicating a two-photon process. In the absence of water the intensity decay was close to a single exponential, but displayed some evidence of an excited state process. In the presence of 1% water the emission spectra shifted dramatically to long wavelength. Water also resulted in wavelength-dependent intensity decays with negative pre-exponential factors on the long wavelength side of the emission, demonstrating the presence of an excited state reaction. At this water concentration the results are consistent with a two-state model due to emission from dioxane and a dioxane and a dioxane-water complex.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore 21201, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Lakowicz
authors.forename: I
authors.initials: I
authors.lastname: Gryczynski
authors.forename: K
authors.initials: K
authors.lastname: Nowaczyk
mesh_terms: D004146:Dioxanes / Q000737:chemistry* / Q000528:radiation effects*; D008956:Models, Chemical; D010777:Photochemistry; D017785:Photons; D012996:Solutions; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014867:Water
chemical_list: D004146:Dioxanes; D012996:Solutions; D014867:Water; C025223:1,4-dioxane