title: Syntheses, and optical, fluorescence, and nonlinear optical characterization of phosphine-substituted terthiophenes.
abstract: Earlier studies of phosphine-substituted terthiophenes have demonstrated that some of these materials exhibit nonlinear absorption at 532 nm. However, this wavelength is significantly removed from the linear absorption maxima of the complexes, suggesting that better nonlinear absorption might be observed at wavelengths closer to the linear absorption maxima. To investigate this possibility, a library of compounds has been prepared either by varying the group attached to the nonbonding pair of electrons on the phosphorus atoms of 5,5''-bis(diphenylphosphino)-2,2':5',2''-terthiophene (PT(3)P), or by introducing additional substituents on the 5''-position of 5-(diphenylphosphino)-2,2':5',2''-terthiophene (PT(3)). All these compounds have been characterized using multinuclear NMR, UV-vis, and fluorescence spectroscopy. The compounds are strongly fluorescent, and both the fluorescence wavelength and the intensity depend upon the thiophene substituents. The nonlinear optical properties have also been evaluated at various wavelengths in the blue region. Each compound exhibits reverse saturable absorption, and the intensity of the reverse saturable absorption at a particular wavelength depends on the chemical structure of the compound.
authors.affiliation: Department of Chemistry, The University of Alabama at Birmingham, 1530 Third Avenue S., Birmingham, Alabama 35294, USA.
authors.forename: Qun
authors.initials: Q
authors.lastname: Zhao
authors.forename: Jianwei
authors.initials: J
authors.lastname: Wang
authors.forename: Jason L
authors.initials: JL
authors.lastname: Freeman
authors.forename: Makeba
authors.initials: M
authors.lastname: Murphy-Jolly
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Wright
authors.forename: Debra J
authors.initials: DJ
authors.lastname: Scardino
authors.forename: Nathan I
authors.initials: NI
authors.lastname: Hammer
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Lawson
authors.forename: Gary M
authors.initials: GM
authors.lastname: Gray