title: Dual-emissive photoluminescent Langmuir-Blodgett films of decatungstoeuropate and an amphiphilic iridium complex.
abstract: Langmuir monolayers and Langmuir-Blodgett (LB) films of the decatungstoeuropate [Eu(W(5)O(18))(2)](9-) (EuW(10)) and the amphiphilic Ir complex 1 have been successfully fabricated by using the adsorption properties of the EuW(10) polyanion dissolved in the aqueous subphase onto a positively charged 1 monolayer at the air-water interface. The compression isotherms and Brewster angle microscopy (BAM) of monolayers of 1 on pure water (1 monolayer) and on a subphase containing 10(-6) M EuW(10) and 10(-3) M NaCl (1/EuW(10) monolayer) have been studied. Infrared and UV-vis spectroscopy of the transferred LB films indicate that EuW(10) and 1 molecules are incorporated within these LB films. X-ray reflectivity (SXR) and atomic force microscopy (AFM) experiments indicate that LB films of 1 present a heterogeneous morphology while 1/EuW(10) films show a flatter and more homogeneous surface as well as a layered structure with a periodicity of 4.1 nm. Mixed monolayers of 1 and DODA (dimethyldioctadecylammonium bromide) have been prepared with EuW(10) polyanions in the subphase to control the concentration of 1 and EuW(10) polyanions within the LB films. AFM and SXR experiments with the transferred LB films show that the dilution of 1 with DODA improves the layered structure. The luminescence of 1 is partially quenched by EuW(10) in the 1/EuW(10) LB films, while emission from EuW(10) is not detected. On the other hand, emission from both entities is preserved in the LB films prepared from mixed DODA/1 monolayers, in which the red and yellow emissions arise independently from EuW(10) and 1, respectively. The different DODA:1 ratios lead to changes in the emission color. Therefore, they constitute a promising color-tunable luminescent material.
authors.affiliation: Instituto de Ciencia Molecular, Universidad de Valencia, 46980 Paterna, Spain. miguel.clemente@uv.es
authors.forename: Miguel
authors.initials: M
authors.lastname: Clemente-León
authors.forename: Eugenio
authors.initials: E
authors.lastname: Coronado
authors.forename: Angel
authors.initials: A
authors.lastname: López-Muñoz
authors.forename: Diego
authors.initials: D
authors.lastname: Repetto
authors.forename: Takeru
authors.initials: T
authors.lastname: Ito
authors.forename: Takayuki
authors.initials: T
authors.lastname: Konya
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Yamase
authors.forename: Edwin C
authors.initials: EC
authors.lastname: Constable
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Housecroft
authors.forename: Kevin
authors.initials: K
authors.lastname: Doyle
authors.forename: Stefan
authors.initials: S
authors.lastname: Graber