3856
Macromolecules 2002, 35, 3856-3865
Characterization and Fluorescence of Macrocyclic Polystyrene by Anionic End to End Coupling. Role of Coupling Reagents Kurt A. Alberty,† Eric Tillman,† Stephane Carlotti,† Kevin King,‡ Stephen E. Bradforth,† and Thieo E. Hogen-Esch*,‡ Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, University Park, Los Angeles, California 90089-1661
David Parker and W. James Feast Interdisciplinary Research Centre in Polymer Science and Technology, University of Durham, South Road, Durham DH1 3LE, United Kingdom Received October 12, 2001; Revised Manuscript Received March 4, 2002
ABSTRACT: Macrocyclic polystyrene (PS) was synthesized by initiation of styrene by naphthalide anion or benzylic dianions in the presence of Li or K ions followed by reaction of the resulting PS dianions with dibromomethane (DBM) or 1,4-bis(bromomethylbenzene) (DBX) in THF at -78 °C under high dilution conditions. MALDI and NMR studies of the DBM cycles showed the presence of 1,2-diphenyl linkages. Fluorescence studies on the DBM cycles show strongly enhanced and anomalous structured emission bands between 300 and 320 nm attributable to linear chains containing styrenic chain end impurities. This indicates rapid metal bromine exchange to give chain end benzyl bromides that eliminate with polystyryl anion to give small (95
