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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 (<1.0%) fractions of styrene type chain end structures. In comparison, the cycles obtained with DBX show only the PS monomer and excimer bands at 285 and 330 nm, respectively, and appear to be substantially free of such side reactions. These DBX coupled cycles show up to a 2-fold enhancement in the monomer fluorescence at low MW compared with matching linear polystyrenes that show essentially no MW dependence. This may be due to the increased rigidity of the cycles as molecular weights decrease and appears to be a general feature for cyclic vinyl aromatic polymers.

We report the experimental observation of magnetic field deformation of spherical nanocapsules, self-assembled from sexithiophene molecules, into oblate spheroids, confirming a long-standing theoretical prediction. The magnetically deformed objects can be trapped in a compatible organogel to make them suitable for further investigations and applications. Our results show that strong magnetic forces can be effectively used, in a contact-free manner, as a tool to control the self-organization of a whole class of functional organic molecules.

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