Published on Web 09/13/2006
Luminescent Triarylborane-Functionalized Polystyrene:
Synthesis, Photophysical Characterization, and Anion-Binding
Studies
Kshitij Parab, Krishnan Venkatasubbaiah, and Frieder Ja¨kle*
Contribution from the Department of Chemistry, Rutgers UniVersity-Newark, 73 Warren Street,
Newark, New Jersey 07102
Received May 11, 2006; E-mail: fjaekle@rutgers.edu
Abstract: A new class of highly fluorescent triarylborane polymers has been prepared from trimethylsilyl-
substituted polystyrene via a modular approach that involves selective polymer modification reactions with
organometallic reagents. The photophysical properties, environmental stability, and the Lewis acidity of
the boron sites have been tailored through modifications in the substitution pattern on boron. The
photophysical properties are indicative of electronic communication between the chromophores attached
to polystyrene, which has been exploited for the efficient probing of fluoride and cyanide in the micromolar
concentration range.
Introduction
The respective polymeric analogues are particularly intriguing
due to the opportunity of using solution processing techniques
for device fabrication and, in the case of sensor materials, the
possibility of signal amplification effects.6 In particular, the
discovery and development of hydroboration polymerization
procedures by Chujo and co-workers has made organoboron
polymers that contain electron-deficient boron groups in the
conjugated polymer backbone readily accessible.7 Several other
techniques for the incorporation of boron moieties into the
backbone of conjugated organic and organometallic polymers
have also been reported.8 Many of these polymers show very
interesting photophysical properties and may even act as novel
n-type polymers in electronic devices.9
Recent interest in the incorporation of boron into extended
organic π systems is to a large extent due to the intriguing
electronic and photophysical properties that are commonly
encountered.1,2 The latter arise as a result of overlap between
the empty p orbital on boron and the conjugated π system and
can thus systematically be modified either through variation of
the organic π system or by fine-tuning the Lewis acidity of
boron itself. Materials of this kind have been extensively used,
for example, in linear and nonlinear optics,3 as emission and
electron conduction layers in organic light emitting devices
(OLEDs),4 and as luminescent probes for anions.5
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10.1021/ja063302v CCC: $33.50 © 2006 American Chemical Society
J. AM. CHEM. SOC. 2006, 128, 12879-12885
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