Preparation And Luminescence Properties Of Anthracene-triphenylamine Chromophores In Aggregation And Composite With Metal Cluster

Organic materials with large"Ï€"conjugation possess strong intramolecular charge transfer and usually, result in strong fluorescence emission. Based on this idea, we designed and synthesized several anthracene-triphenylamine chromophores that have obvious D-Ï€-A-Ï€-D intramolecular charge transfer characteristic. Optical properties including absorption, one-photon fluorescence and two-photon fluorescence properties of anthracene-triphenylamine chromophores in solution and aggregation as well as the composite with metal cluster were investigated.Firstly, four new chromophores, named as EAn-G1,EAn-G2,BAn-C and BAn-E, have been synthesized and their structures have been confirmed. And their absorption, one-photon fluorescence or two-photon fluorescence properties in solution state have been measured.Secondly, we studied comparatively the fluorescence properties of newly synthesized anthracene-based chromophores (EAn-G1,EAn-G2,BAn-C and BAn-E) and some other anthracene-triphenylamine chromophores (MAn-G1, MAn-G2, AAn-G1, AAn-G2 obtained by our group) in aggregation states.Finally, the composite of anthracene-triphenylamine chromophores and metal cluster were prepared and the corresponding optical properties were investigated.The results have shown as follows:1,Molecular fluorescence enhancement is strongly affected by the central"core". For example, the fluorescence intensities in solution are in the order of AAn > E An > MAn (for generation 1), MAn > AAn > EAn(for generation 2) due to the chromophore have different core. With the generation increased, chromophores showed both one-photon and two-photon fluorescence enhancement. Thus, the orders of AAn-G2 > AAn-G1, EAn-G2 > EAn-G1 and MAn-G2 > MAn-G1 are obtained.2,Interestingly, the fluorescence enhancement in aggregation states were observed in compared with those of solution-state. Large Stokes'shifts at 205 nm (8500 cm-1) for AAn-G2 and 183 nm (7800 cm-1) for MAn-G1 and 172 nm (7500 cm-1) for MAn-G2 in aggregation were obtained which are contribution to eliminating the self-absorption phenomena.3,The combination of chromophores aggregation and the Au cluster wrapped by SiO2 makes the fluorescence enhancement, resulting from the energy-band resonance between organic and inorganic compounds.