Dibenzo‐24‐crown‐8‐terminated polystyrene (5) was chain extended to “dimeric” 8 by pseudorotaxane formation with a ditopic guest, α,ω‐bis[p‐(N‐benzylammoniomethyl)phenoxy]heptane bis(hexafluorophosphate) (7). The three‐armed star polymer 11 was similarly formed by complexation of the dibenzo‐24‐crown‐8‐terminated polystyrene (5) with a tritopic secondary ammonium salt, 1,3,5‐tris[p‐(benzylammoniomethyl)phenyl]benzene tris(hexafluorophosphate) (10). Another three‐armed star polymer 13 was self‐assembled from dibenzo‐24‐crown‐8‐terminated polystyrene (5) and a tetratopic paraquat compound, 1,2,4,5‐tetrakis{p‐N‐[(N′‐methyl‐4,4′‐bipyridinium)methylphenyl]}benzene octakis(hexafluorophosphate) (12). The above chain extension and star polymer formation processes seemed to be cooperative; that is, the second and third complexation steps proceed with stepwise higher efficiencies than statistically expected. Dibenzo‐24‐crown‐8‐terminated polystyrene (5) was chain extended with secondary ammonium terminated polystyrene 14, forming 16, and also self‐assembled with a secondary ammonium ion terminated polyisoprene 15 to form supramolecular block copolymer 17. These processes were examined by NMR, mass spectrometry and viscometery. Thus, although binding in these systems is not particularly strong (association constants <104 M−1), these examples provide proof‐of‐principle that pseudorotaxane formation is a viable concept for chain extension and self‐assembly of novel types of block copolymers and star polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3518–3543, 2009

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This paper reports the preparation and characterization of a new aromatic polyazomethine with rotaxane architecture. The complex of β-cyclodextrin and 1,4-phenylenediamine was treated with N-n-butyl-3,6-diformylcarbazole, which is large enough to prevent dethreading. The polycondensation reaction was performed in N,N-dimethylformamide leading to polyazomethine soluble in polar solvents. Measurements made by gel permeation chromatography of the dimethylformamide-soluble (DMF) soluble polyazomethine show the presence of high molecular weight material. The structure and thermal properties of the resulting polymer were characterized by IR, 1 H NMR, TGA and DSC techniques.

Polyfluorene PF center dot CD rotaxane copolymer, composed of randomly distributed 9,9-dioctylfluorene, methyltriphenylamine (electron-donating) and 9-dicyanomethylenefluorene complexed with -cyclodextrin (CD) (electron-accepting) structural units, has been synthesized by Suzuki cross-coupling reaction. The chemical structures were proved by FTIR and 1H NMR spectroscopy. The surface morphology, thermal, optical, electrochemical behavior, and adhesion characteristics of the obtained rotaxane copolymer have been investigated and compared with those of the nonrotaxane counterpart (PF). Relatively high fluorescence efficiency, almost identical normalized absorbance maximum in solution and solid-state of PF center dot CD rotaxane copolymer, and a more uniform and smoother surface with lower adhesion forces provides the role of CD encapsulation on the lower aggregation propensity. PF center dot CD and PF copolymers exhibit n- and p-doping processes and blue-light emission in the film state. The optical and electrochemical band gaps (Eg), as well as the highest occupied molecular orbital/lowest unoccupied molecular orbital positions in an energetic diagram indicate that both copolymers are promising blue-emitting electroluminescent materials

The photophysical properties of two polyrotaxanes (PFBTh•PSbCD and PFBTh•PMebCD) composed of fluorene and bithiophene encapsulated into permodified b-cyclodextrin cavities have been investigated and compared with those of the reference PFBTh. Rotaxane formation results in improvements of the thermal stability, solubility in common organic solvents, as well as better film forming ability combined with a high transparency. As expected PFBTh and its encapsulated forms absorb at wavelengths beyond 510 nm, and time-resolved photoluminescence (PL) in solution shows a well-define vibronic structures with a predominance of the 0-0 transitions and an energy difference of 0.16 eV. The fluorescence lifetimes follow a monoexponential decay with a value s 5 630 6 30 ps. Atomic force microscopy, AFM, indicated a tendency of polyrotaxanes to organize into fibers. The advancing contact angles indicated higher surface hydrophobicity and lower surface free-energy values for polyrotaxanes compared with their unthreaded analogues. The device based on PFBTh•PSbCD:PCBM in a 1/1 w/w ratio under simulated AM 1.5G illumination at 100 mW cm 22 exhibited improved photovoltaic parameters of cells, resulted in high V oc (0.68 V), J sc (1.65 mA cm 22 ), FF (31.6%), and PCE (0.35) values, compared with PFBTh or PFBTh•PMebCD, respectively.