Poly(p-phenylenevinylene) Derivatives with Defined Conjugation Segments and Post-Polymerization Modification with Sterically Enshrouded Chromophores Ashley A. Buelt, Allison J. Colberg, Ashlyn E. Dennis, Kristine M. Jecen, Brad P. Morgan, Rhett C. Smith* Introduction The rapid evolution of CP research from the initial discovery of their metallic conductivity in the doped state in the 1970s [1–4] to the utility of CPs in commercial devices has been one of the great success stories in materials science over the last half century. Ongoing interest in improving such systems has lead to an ever-increasing sophistication of polymer structures and nano/molecular architectures being explored. [5] These studies are driven in part by the widespread recognition that application of CPs in techno- logically viable contexts requires careful control of the interchain interactions that dictate energy and charge transfer (CT)/mobility processes, exciton migration/con- finement, etc. [6–9] These processes can be decidedly influenced by the presence of defects resulting from a particular synthetic methodology, the manner in which polymer films are formed, and other subtle considera- tions. [10–17] Disruption of conjugation by incorporating functionalities that twist the p-system from coplanarity is one strategy that facilitates exciton confinement. [15] Another strategy towards tuning CP photophysical profiles is to prepare hyperbranched luminescent polymers that bear functionalities that allow them to be functionalized post-polymerization, [18] thus affording a remarkable plat- form for tailored application and property acquisition. In the current work, we have prepared p-conjugated polymers featuring both periodic disruptions of conjugation in the form of m-phenylene units, and iodo Communication A. A. Buelt, A. J. Colberg, A. E. Dennis, K. M. Jecen, B. P. Morgan, R. C. Smith Department of Chemistry and Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University, Clemson, SC, USA Fax: (þ1) 864 656 6613; E-mail: rhett@clemson.edu Two poly( p-phenylenevinylene) derivative alternating copolymers (P1-I and P2-I) have been prepared featuring iodo substituents and m-phenylene units to periodically disrupt conju- gation. P1-I was derivatized with various chromophores to yield P1a-f. In P1a-f, the chromo- phores were positioned within a sterically protected pocket shielding them from interchain interactions so that intrachain interactions between polymer segments could be observed. Solution and film properties of polymers have been examined. Post-polymerization chromo- phore modification leads to new photophysical properties such as intramolecular charge trans- fer and fluorescent resonance energy transfer processes in some cases. 752 Macromol. Rapid Commun. 2010, 31, 752–757 ß 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim DOI: 10.1002/marc.200900755