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Herein, we report the synthesis of inclusion complexes (ICs) based on 3,4-ethylenedioxythiophene (EDOT) with permethylated β-cyclodextrins (TMe-βCD) and permethylated γ-cyclodextrins (TMe-γCD) host molecules. To prove the synthesis of such ICs, molecular docking simulation, UV-vis titrations in water, 1H-NMR, and H-H ROESY, as well as matrix-assisted laser desorption ionization mass spectroscopy (MALDI TOF MS) and thermogravimetric analysis (TGA) were carried out on each of the EDOT∙TMe-βCD and EDOT∙TMe-γCD samples. The results of computational investigations reveal the occurrence of hydrophobic interactions, which contribute to the insertion of the EDOT guest inside the macrocyclic cavities and a better binding of the neutral EDOT to TMe-βCD. The H-H ROESY spectra show correlation peaks between H-3 and H-5 of hosts and the protons of the guest EDOT, suggesting that the EDOT molecule is included inside the cavities. The MALDI TOF MS analysis of the EDOT∙TMe-βCD solutions clearly reveals the presence of MS peaks corresponding to sodium adducts of the species associated with the complex formation. The IC preparation shows remarkable improvements in the physical properties of EDOT, rendering it a plausible alternative to increasing its aqueous solubility and thermal stability.

In the present study, we investigated the effect of permodified 2,3,6-tri-O-trimethylsilyl β- and γ-cyclodextrin (TMS·β-CD, TMS·γ-CD) encapsulation on the optical, electrochemical, morphological, and supramolecular arrangements of a poly[2,7'-(9,9-dioctylfluorene-alt-2',7-fluorene)] PF copolymer. For this purpose, the photophysical properties and Langmuir monolayer formation of PF·TMS·β-CD and PF·TMS·γ-CD polyrotaxanes were investigated and compared with those of the reference PF. Surface pressure-area isotherms and Brewster angle microscopy studies indicated the capability of both polyrotaxanes to organize into larger and homogeneous 2D supramolecular assemblies at the air-water interface. The obtained results suggest that the presence of the surrounding TMS·β-CD and TMS·γ-CD macrocycles on the PF backbones leads to changes in the conformation and hydrophobicity of the film surfaces. Our investigation offers a method to assess the impact of TMS-CD encapsulation on the control of 2D monolayer formation, with particular attention on the generation of stable PF monolayers for organic electronic devices.

This study summarizes our recent endeavors, related to the design, synthesis, and photophysical characteristics of polythiophenes and polyfluorenes homo- or copolymers, and poly(3,4-ethylenedioxythiophene) encapsulated into cucurbit[7]uril (CB7) cavities involving different synthetic strategies. For the sake of comparison, the photophysical properties of these polyrotaxanes were compared to those of their nonthreaded homologs. CB7-based conjugated polyrotaxanes exhibit advantageous photophysical and transport properties, which makes them suitable in optoelectronic applications.

This work deals with the effect of chemical structure and iodine doping on electro-optical characteristics of different polysilanes in the solid state. The properties of polymethylphenylsilane homo...

New supramolecular networks were synthesized by cross-linking reaction of polyethylene glycol (PEG) polyrotaxane with a 10 wt% of poly(3,4-ethylenedioxythiophene) (PEDOT) polyrotaxanes. For comparison purpose, a cross-linked material of PEG polyrotaxane with PEDOT non-rotaxane counterpart was also synthesized under similar conditions. The chemical structures of these compounds were evidenced by using ATR-FT-IR and WAXS. The thermal stability was evaluated by TGA analysis. The evolution of dielectric constant and dielectric loss by varying the temperature and frequency, and conductivity of the investigated compounds were compared with those of the pure cross-linked material. The value of the dielectric constant of pure cross-linked film at 10 Hz frequency is 2.6, whereas for the film with PEDOT-βCD polyrotaxane incorporated into the matrix increases to 32, which are consistent with the dielectric loss and conductivity results. At the lower temperature region, the alternating current conductivity (σAC) increases monotonically with increasing of frequency, denoting that the conductivity of short-range species is predominant. When the temperature increases, the direct current conductivity (σDC), corresponding to the long-range mobility of the free charges is independent of the frequency.

In this study, we investigate the influence of γ-cyclodextrin (γCD) or octakis-(2,3,6-tri-O-methyl)-γ-cyclodextrin (TMe-γCD) encapsulation on the solubility, thermal, optical, electrochemical, morphological, and electrical properties of an aromatic polyazomethine (PA). PA was prepared by oxidative C C coupling of pyrenyl groups from the monomer MA using FeCl3 as catalyst in DMF. After threading of γCD or TMe-γCD macrocycles onto the PA chains, the 1H NMR spectra were in line with the formation of the respective inclusion complexes, PA·γCD and PA·TMe-γCD, which showed distinct improvements of their solubility in common organic solvents, higher thermal stability, as well as better film-forming ability. Fluorescence spectroscopy revealed that the emission maximum shifted from 388 nm for PA to 425 nm and 428 nm for PA·γCD and PA·TMe-γCD, which is in good agreement with encapsulation of PA backbones into the hydrophobic cavities. Fluorescence lifetime measurements indicated multiexponential decays for all compounds, which is in accordance with different conformers in the excited state. Atomic force microscopy indicated that the surfaces of PA·γCD and PA·TMe-γCD in the solid state showed needle-shaped morphologies with widths of 105 ± 25 nm and 46 ± 13 nm, respectively, whereas the surface of the naked PA polymer displayed an irregular morphology with embedded particles and width of 158 ± 29 nm. The electrochemical band gaps (ΔEg) of PA·γCD and PA·TMe-γCD were lower than that of non-encapsulated PA. The electrical conductivities of the investigated compounds were about 10−11 S cm−1, which is in the range of insulating materials.

Cucurbit[7]uril (CB7), native α-cyclodextrin (αCD) and its tris-O-methylated derivative (TMαCD) as macrocyclic host molecules and amine-terminated poly(ethylene glycol) (PEG) as neutral guest were used for the synthesis of 3-CB7, 3-αCD and 3-TMαCD polyrotaxanes. The binding affinities of the neutral PEG guest into the CB7, αCD and TMαCD cavities were evaluated by isothermal titration calorimetry. The high value of the stability constant (1 × 104 M−1) indicates that PEG provides a preferential binding to CB7 over αCD. The polyrotaxane structure was confirmed by FT-IR and 1H NMR spectroscopy. The coverage ratio of the PEG with CB7, αCD and TMαCD macrocycles, were 63%, 71%, and 30%, respectively. The polyrotaxanes 3-CB7 and 3-αCD exhibit an enhancement in thermal stability compared with the non-rotaxane 3 counterpart. In addition, polyrotaxane 3-CB7 shows blue-shifted absorption by more than 20 nm and enhanced water solubility.

We report the effect of the macrocyclic encapsulation on the photophysical properties of poly(9,9-dioctylfluorene-alt-bithiophene) polyrotaxanes copolymers. The encapsulated compounds were synthesized by Suzuki cross-coupling reaction between 5,5'-dibromo-2,2'-bithiophene (DBT) inclusion complexes in randomly methylated β-cyclodextrin (RM-βCD), 2,3,6-tri-O-methyl β-cyclodextrin (TM-βCD), 2,3,6-tri-O-trimethylsilyl β-cyclodextrin (TMS-βCD) or cucurbit[7]uril (CB7) with a bulky 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol) ester (DF) as stoppers. These supramolecular compounds exhibited distinct improvement in the solubility, molecular weight, film forming ability, surface-morphological characteristics and reduced aggregation tendency compared to those of the neat compound. Also, the threading of conjugated backbones into macrocycles leads to an increasing environmental stability and resistance to quenching from impurities. Fluorescence emission (PL) shows vibronic transitions and a mono-exponential kinetics. The electrochemical data provided that the investigated compounds exhibited n- and p-doping processes. The encapsulation of DBT into TM-βCD or TMS-βCD cavities exhibits a greater effect on the LUMO, while the encapsulation into CB7 affects the HOMO energy levels. The HOMO/LUMO energy levels indicate that the investigated polyrotaxanes are electrochemically accessible as electron-transporting materials in electronic devices. Based on AFM analysis, polyrotaxane compounds exhibits a higher tendency to organize into fibers or linear ribbons.

We report on the synthesis as well as the optical, electrochemical and morphological properties of two polyrotaxanes (4a and 4b), which consist of electron-accepting 9,9-dicyanomethylenefluorene 1 as an inclusion complex in persilylated β- or γ-cyclodextrin (TMS-β-CD, TMS-γ-CD) (1a, 1b) and methyltriphenylamine as an electron-donating molecule. They are statistically distributed into the conjugated chains of 9,9-dioctylfluorene 3 and compared with those of the corresponding non-rotaxane 4 counterpart. Rotaxane formation results in improvements of the solubility, the thermal stability, and the photophysical properties. Polyrotaxanes 4a and 4b exhibited slightly red-shifted absorption bands with respect to the non-rotaxane 4 counterpart. The fluorescence lifetimes of polyrotaxanes follow a mono-exponential decay with a value of τ = 1.14 ns compared with the non-rotaxane, where a bi-exponential decay composed of a main component with a relative short time of τ1 = 0.88 (57.08%) and a minor component with a longer lifetime of τ2 = 1.56 ns (42.92%) were determined. The optical and electrochemical band gaps (ΔEg) as well as the ionization potential and electronic affinity characterized by smaller values compared to the values of any of the constituents. AFM reveals that the film surface of 4a and 4b displays a granular morphology with a lower dispersity supported by a smaller roughness exponent compared with the non-rotaxane counterpart.

Poly[2,7-(9,9-dioctylfluorene)-alt-(5,5′-bithiophene/permethylated β-cyclodextrin) (3·PMeβCD) main-chain polyrotaxane was synthesized according to a Suzuki-type aryl-aryl coupling protocol, by reacting 9,9-dioctylfluorene-2,7-trimethylene diborate (1) with an inclusion complex of 5,5′-dibromo-2,2′-bithiophene (2)/permethylated-βCD (PMeβCD) (2·PMeβCD). The complexation ability of PMeβCD molecule towards monomer 2 was confirmed by MM+ and PM3 quantum-mechanics semi-empirical methods, ESI-MS, (ESI) MS/MS analysis, as well as FTIR and 1H-NMR spectroscopy. A conjugated polyrotaxane copolymer with PMeβCD/structural unit ratio of about 1/3 and the number average molecular weight (Mn) value of 30600 was obtained by 1H-NMR spectroscopy and gel permeation chromatography, respectively. The thermal, optical, surface morphology and the adhesion characteristics were investigated and compared to those of the non-rotaxane counterpart poly[2,7-(9,9-dioctylfluorene)-alt-(5,5′-bithiophene) (3).

Poly[2,7-(9,9-dioctylfluorene)-alt-(2,7-fluorene/cucurbit[7]uril)] polyrotaxane was synthesized according to Suzuki coupling protocol in DMSO, by reacting 2,7-dibromofluorene encapsulated into the cucurbit[7]uril (CB7) cavity with 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol) ester. The Ka value (9.5 × 103 M−1) indicates that 2,7-dibromofluorene provides a preferential binding to CB7, which allows the synthesis of a polyrotaxane with a CB7/structural unit ratio of about 1/3 and higher molecular weights. The chemical structure was proven by FTIR and 1H NMR spectroscopy. The thermal, optical, electrochemical, wetting, and surface morphological properties of the polyrotaxane have been investigated and compared to those of the neat copolymer. The polyrotaxane exhibits an enhancement in the glass transition temperature, blue-shifted absorption by about 11 nm, and a subtle effect on the LUMO energy levels. The fluorescence lifetimes follow a mono-exponential decay with a value of τF = 0.7 ns. The electrochemical band gap of the polyrotaxane (3.39 eV) is smaller than that of the uncomplexed compound. Wetting properties reveal a change in the distribution of the dispersive and polar components of the surface free energy through the CB7 encapsulation. Atomic force microscopy indicated further that the polyrotaxane film is uniformly distributed over the substrate area with a regular consistency and lower roughness parameters.

In this study, we have investigated the effect of oligomerization and rotaxane formation on the optical and surface-morphological properties of pyrene–triazole azomethine based compounds. The combined effects of oligomerization and rotaxane formation improve the solubility, film forming ability, photophysical (increased fluorescence intensity and lifetime), and morphological properties of the azomethine oligomers. Upon rotaxane formation, the root-mean-square roughness of the films decreased from 3.5 to 1.0 nm (determined by AFM). On the contrary, no remarkable difference was found on the electrical conductivity of the iodine-doped rotaxane oligomer as compared to its un-doped form.

M/α-CD azomethine [2]-rotaxane composed of a triazole/α-cyclodextrin (α-CD) inclusion complex and bulky pyrene groups linked together through azomethine bonds has been studied by thermal analysis and quantum semi-empirical method PM3. The comparison of the monomer rotaxane and non-rotaxane structures reveals that [2]-rotaxane formation is sufficient to increase the thermal stability of the non-rotaxane M monomer, as well as favorable solubility characteristics. Semi-empirical calculations confirmed that α-CD macrocycles are sufficiently large to thread onto the triazole rings, while the pyrene moieties are sufficiently large to serve as stoppers in the resulting [2]-rotaxane.

The surface properties of two conjugated main-chain polyrotaxanes, polyazomethine threaded on α-cyclodextrin (PA/α-CD), and 9,9-dioctylfluorene-bithiophene copolymer threaded on randomly methylated β-cyclodextrin (PF-BT/RM-βCD) were investigated and compared with PA and PF-BT non-rotaxane copolymers. Optical microscopy study of PF-BT/RM-βCD polyrotaxane showed the self-assembling of the lamellae into 3D large flat worm-like structures with an almost parallel distribution compared with disordered PF-BT reference copolymer. Lower values of the interfacial adhesion forces of polyrotaxane films, obtained by atomic force microscopy (AFM), were assigned both to the interactions of macrocycles with hydrophobic substrate and to their aggregation tendency.

The paper reports on the preparation of a new 2-rotaxane monomer through an acid coupling reaction between 1-pyrenecarboxaldehyde and α-CD/3,5-diamino-1,2,4-triazole inclusion complex. Pyrenyl groups are large enough to provide a blocking effect toward cyclodextrin de-threading. The oxidative C―C coupling of 2-rotaxane in the presence of RuCl 3 catalyst afforded conjugated azomethine polyrotaxanes. The expected modifications of the solubility, morphology, film forming ability for rotaxane polymer were proved. As shown by fluorescence and UV-vis spectroscopy, a material with optical properties appropriate for use in photonics was obtained.

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

Poly[2,7-(9,9-dioctylfluorene- alt -2,7-fluorene/β-CD)] main chain polyrotaxane was synthesized through organometallic Suzuki coupling by reacting β-cyclodextrin/2,7-dibromofluorene inclusion complex with 9,9-dioctylfluorene-2,7-bis(trimethyleneborate). The IR, NMR and elemental analysis data support the presence of β-cyclodextrin in the copolymer structure. No glass transition or melting phenomena were detected in DSC curves of the polyrotaxane on the heating run in the 50–250 ° range. As compared with the reference copolymer obtained in the absence of β-cyclodextrin, the rotaxane copolymer is more hygroscopic and soluble in polar/non-polar solvent mixtures. The expected modification of the optical properties of the fluorene copolymer with rotaxane architecture in the main chain was proved by fluorescence and UV–vis spectroscopy and consists in a blue-shifted emission.

Epoxy-terminated polydimethylsiloxanes of two molecular weights (M n about 1,250 and 2,100) were proved to undergo inclusion complexation into the inner cavity of γ-cyclodextrin, thus resulting in formation of polyrotaxanes. The supramolecular assembling, the structure, the morphology, and the thermal properties of polyrotaxanes were shown to depend on the polymer molecular weight, the molar ratio between the components, and the presence of free γ-cyclodextrin.

To improve the physical properties of polymer materials, a novel copolymer with a multiply blocked rotaxane architecture in the main chain was synthesized through Suzuki dehalogenative polycondensation from a 2,7-dibromofluorene/γ-cyclodextrin (γ-CD) inclusion complex and 9,9-dioctylfluorene-2,7-trimethylene diborate in the presence of a tetrakis(triphenylphosphine)palladium(0) catalyst. As demonstrated by computational calculations, the dioctyl groups were large enough to prevent the dethreading of γ-CD molecules. A copolymer polyrotaxane with a γ-CD/structural unit ratio as high as 1/1.4 and a bimodal molecular weight distribution was obtained, as proved by its 1H-NMR spectrum and size exclusion chromatography curve, respectively. The polyrotaxane showed lower thermal stability and higher solubility in polar solvents in comparison with the noncomplexed homologue. The fluorescence spectra of both the complexed and noncomplexed copolymers exhibited typical well-resolved blue emission bands that arose from the fluorene chromophore units. In dimethylformamide solutions, the ratio of the intensities of the peaks of the emission spectra (emission spectra intensities413 for the 0–0 band and emission spectra intensities437 for the 0–1 band) was higher for the polyrotaxane than the noncomplexed copolymer, and this demonstrated a reduced quenching effect of the environment induced by the protection of the polymer chain by the macrocycle. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The effect of complexation of a poly[2,7-(9,9-dioctylfluorene- alt -2,7-fluorene)] copolymer into the inner cavity of γ-cyclodextrin on the morphology, the optical and the electrical properties was investigated. The fluorescence spectra of the rotaxane copolymer and of a reference, non complexed copolymer exhibit typical well resolved blue emission bands arising from the fluorene chromophore units. The complexation of the fluorene copolymer chain increases the fluorescence lifetime from 0.54 to 0.59 ns and decreases the activation energy of the electrical conduction from 2.41 to 1.49 eV. The rotaxane copolymer presents higher semiconducting properties as compared to the reference copolymer.

β-Cyclodextrin ( 1 -CD) and 2 -cyclodextrin ( 2 -CD) (hosts) formed inclusion complexes with 4,41-bipyridinium dication derivatives with long chains (guests), in which the substituents on the bipyridinium nitrogen atoms are 1,3-bis(chloromethylphenethyl)-1,1,3,3-tetramethyldisiloxane. The number of 2 -CD molecules threaded onto the polymer chain increases with the length of the guest chain. In contrast, the number of β-CD molecules threaded onto the polymer is approximately 4 corresponding to each molecular chain, due to the repulsive interaction between β-CD and the quaternary bipyridinium units. The complexes were isolated in high yield and characterized by 1H NMR, 13C NMR, X-ray diffraction, thermal and scanning electron micrographs studies. As proven by X-ray analysis, the synthesized polyrotaxanes are crystalline materials with crystalline patterns significantly different from that of native cyclic oligosaccharide. The thermal stabilities of polyrotaxanes are higher than that of the physical mixture between cyclodextrin and the alternating copolymer, denoting the formation of the inclusion complexes. Scanning electron micrographs of polyrotaxanes reveal cubic and linear shapes without a well formed shape. Shape regularity and geometrical regularities in the agglomerating forms can be observed.

Epoxy-terminated polydimethylsiloxanes (E-PDMSs) of different molecular weight Mn were proved to undergo inclusion complexation into the inner cavity of β-cyclodextrin (β-CD), resulting in polyrotaxanes (PRots). The dethreading of the macrocycle was prevented by blocking the siloxane chain with a bulky substituent derived from 4-aminophenyltriphenyl methane (APhTPhM). As revealed by thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy (SEM), wide-angle X-ray diffraction and statistical analysis of SEM images, the thermal properties and the morphology of polyrotoxanes are dependent upon Mn, β-CD/E-PDMS molar ratio and the presence of free β-CD in the complexes.

The optical, electrochemical, morphology as well as surface free-energies of poly[(9,9-dioctylfluorene- alt -bithiophene/cucurbit[7]uril)] ( PF-BT•CB7 ) have been investigated and compared with those of the reference PF-BT . The absorption of PF-BT•CB7 and PF-BT extend beyond 500 nm; the maxima appear at 390 and 450 nm, respectively. The fluorescence quantum yield decreases from 0.5 for PF-BT to 0.4 for PF-BT•CB7 , while the fluorescence lifetime follow an opposite trend. The presence of the CB7 macrocycle affects the LUMO more than the HOMO one, which leads to a larger energy gap (2.72 vs 2.60 eV). Atomic force microscopy, AFM, indicated a better tendency of PF-BT•CB7 to organize into extended linear ribbons, i.e. , molecular wires, as compared to PF-BT , which arranged into short C-shaped assemblies. The advancing contact angles indicated also higher surface free-energy values for PF-BT•CB7 than PF-BT , affording materials with a slight tendency of intermolecular interactions.

Two alternating polyfluorene polyrotaxanes (3·TM-βCD and 3·TM-γCD) have been synthesized by the coupling of 2,7-dibromofluorene encapsulated into 2,3,6-tri-O-methyl-β- or γ-cyclodextrin (TM-βCD, TM-γCD) cavities with 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol) ester. Their optical, electrochemical and morphological properties have been evaluated and compared to those of the non-rotaxane counterpart 3. The influence of TM-βCD or TM-γCD encapsulation on the thermal stability, solubility in common organic solvents, film forming ability was also investigated. Polyrotaxane 3·TM-βCD exhibits a hypsochromic shift, while 3·TM-γCD displays a bathochromic with respect to the non-rotaxane 3 counterpart. For the diluted CHCl3 solutions the fluorescence lifetimes of all compounds follow a mono-exponential decay with a time constant of ≈0.6 ns. At higher concentration the fluorescence decay remains mono-exponential for 3·TM-βCD and polymers 3, with a lifetime τ = 0.7 ns and 0.8 ns, whereas the 3·TM-γCD polyrotaxane shows a bi-exponential decay consisting of a main component (with a weight of 98% of the total luminescence) with a relatively short decay constant of τ1 = 0.7 ns and a minor component with a longer lifetime of τ2 = 5.4 ns (2%). The electrochemical band gap (ΔEg) of 3·TM-βCD polyrotaxane is smaller than that of 3·TM-γCD and 3, respectively. The lower ΔEg value for 3·TM-βCD suggests that the encapsulation has a greater effect on the reduction process, which affects the LUMO energy level value. Based on AFM analysis, 3·TM-βCD and 3·TM-γCD polyrotaxane compounds exhibit a granular morphology with lower dispersity and smaller roughness exponent of the film surfaces in comparison with those of the neat copolymer 3.

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, 1H NMR, TGA and DSC techniques. Copyright © 2003 Society of Chemical Industry

The photophysical properties of two polyrotaxanes (PFBTh•PSβCD and PFBTh•PMeβCD) composed of fluorene and bithiophene encapsulated into permodified β-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 τ = 630 ± 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•PSβCD:PCBM in a 1/1 w/w ratio under simulated AM 1.5G illumination at 100 mW cm-2 exhibited improved photovoltaic parameters of cells, resulted in high Voc (0.68 V), Jsc (1.65 mA cm-2), FF (31.6%), and PCE (0.35) values, compared with PFBTh or PFBTh•PMeβCD, respectively. © 2013 Wiley Periodicals, Inc.

Poly(azomethine)s with rotaxane architecture containing a blocking group in every structural unit of the polymer chain have been synthesized by polycondensation of 3,6-diformyl-9-butyl carbazole with 1,6-hexamethylenediamine/α-or β-cyclodextrin adducts. As compared with the polymers obtained in the absence of cyclodextrins, these polymers are more hygroscopic and soluble in polar solvents such as dimethylformamide and dimethyl sulfoxide. The infrared, proton nuclear magnetic resonance, gel permeation chromatography and differential scanning calorimetry data support the presence of cyclodextrins in every structural unit of the polymer chain.

Poly(azomethine)s with rotaxane architecture were synthesized by means of solution polycondensation of terephthalaldehyde with 1,6 -hexamethylenediamine/a- and β-cyclodextrin adducts, and blocking of the chain ends with a bulky aromatic amine, i.e., p-aminophenyltriphenylmethane. As compared with the polymer obtained in the absence of cyclodextrin, these polymers are more hygroscopic and soluble in polar solvents while their IR, NMR and DSC data support the presence of cyclodextrins in the polymer chain.

Polyfluorene PF•γCD rotaxane copolymer, composed of randomly distributed 9,9-dioctylfluorene, methyltriphenylamine (electron-donating) and 9-dicyanomethylenefluorene complexed with γ-cyclodextrin (γCD) (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•γCD rotaxane copolymer, and a more uniform and smoother surface with lower adhesion forces provides the role of γCD encapsulation on the lower aggregation propensity. PF•γCD and PF copolymers exhibit n- and p-doping processes and blue-light emission in the film state. The optical and electrochemical band gaps (ΔEg), 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. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

International audience; Anionic polymerization initiated by cyclodextrins suffers from a poor solubility of those derivatives in standard polymerization solvents. The possibility to perform ethylene oxide polymerization initiated by monofunctional initiators (allyl alcohol, 2-methoxyethanol) by living ring opening polymerization in DMF, a good solvent for any CD derivative, was demonstrated by SEC, 1H and 13C NMR analyses. The study was extended to the use of native CD as initiator, leading to the synthesis of ill-defined structures, explained by the reactivity scale of the various hydroxyl functions. Two selectively modified CD derivatives are then used to synthesize a new family of star-shaped poly(ethylene oxide) polymers with CD core, having 14 or 21 arms. The polymerization was found to be living and DOSY experiments confirmed the well-defined structures for the synthesized star-polymers.

Poly(N-ethyl 3.7-phenothiazinediyl) (1) and poly (N-ethyl 3.7-phenothiazinediyl-co-acetylene) (2) were synthesized by homo- and copolycondensation of 3.7-dibromo N-ethylphenothiazine and 1.2-dibromoethene using a Grignard reaction and NiCl2 or NiCl2.2PPh3 as catalyst. Polymers are soluble in common organic solvents and after doping with iodine have an electrical conductivity of 10−7 −10−6 $$\Omega ^{ - 1} $$ cm−1.

In order to improve the properties of carbon nanotubes, novel calixarene-modified multi-wall carbon nanotubes were prepared by using carbon nanotubes with carboxylic groups and various novel calixarene derivatives. This self-assembling process has allowed us to fabricate carbon nanotubes with functional organic molecules. The properties of the functionalized materials containing carbon nanotubes and calixarene derivatives were studied by using XRD, SEM, FTIR, DRS UV-VIS, and nitrogen adsorption isotherm at 77K.

This paper is devoted to the preparation and characterization of new phenanthroline-triether copolymers with rotaxane architecture by reaction of complexes of α- or β- cyclodextrin and tri(ethylene glycol) ditosylate with 2,9-di(4-hydroxyphenyl)-1,10- phenanthroline, which is large enough to prevent dethreading of cyclodextrin molecules. Comparative 1H-NMR analysis of tri(ethylene glycol) ditosylate complexes and of rotaxane copolymers evidenced the lower cyclodextrin content in rotaxane copolymers as compared to the calculated values. The rotaxane copolymers present bimodal molecular weight distributions attributed to the separation of the fractions with different content of cyclodextrin threaded on the copolymer chain. As evidenced by thermogravimetric analysis, the rotaxane copolymers show higher thermal stability than its non-complexed homologue.