300 Amphiphilic Fluorescent Polythiophene Block-Copolymers Incorporating Low Energy Gap Units

Thursday, November 5, 2009: 2:00 PM
Ballroom C+D (Camino Real Hotel)
Evgueni E. Nesterov , Department of Chemistry, Louisiana State University, Baton Rouge, LA
Jinwoo Choi , Department of Chemistry, Louisiana State University, Baton Rouge, LA
Water-soluble fluorescent polythiophenes are commonly used as a versatile platform for chemo- and biosensors, in design of bioimaging markers, and in other related applications.  These applications would benefit from color-tunable fluorescent emission which can be controlled by the external factors such as analyte binding, temperature, polarity of the environment, etc.  We have developed a versatile method to prepare amphiphilic fluorescent polythiophenes incorporating a low energy gap unit into the conjugated backbone by utilizing metal-catalyzed living polymerization.  These copolymers are characterized by dual-wavelength emission due to the intramolecular excitation energy transfer to the low-gap unit.  The relative intensity of the two emission bands is controlled by supramolecular organization of the copolymer which is strongly affected by the nature of solvent, temperature, etc.  This environment-dependent molecular organization is fully preserved in thin films deposited from solutions of the copolymers.  Synthesis and properties of these block-copolymers will be discussed in this contribution.