In this letter, we describe the preparation of a versatile polymer ligand, which can be attached to CdSe/ZnS semiconductor nanocrystals via a phase transfer reaction. The ligand is based on a chain of reactive esters, which can, in principle, be substituted by any compound containing amino-functionalities. The polymer/nanocrystal complexes are characterized in terms of structure and photostability.

Summary: We report on the synthesis of polyacrylamides that were prepared by the reaction of a reactive ester polymer with a mesogen‐containing secondary amine and N‐methylpiperazine. As the polymers do not form hydrogen bonds near the amide groups, their mobility is significantly higher than that of poly(N‐monoalkylacrylamides). The initially nonionic polymer shows no liquid‐crystalline behavior in bulk and in mixture with ethylene glycol. This is due to the low polarity difference between the different side chains. The polarity difference can be increased by protonation or quarternization of the tertiary amino groups, and liquid‐crystalline behavior is observed. The self‐assembly multilayer build‐up of the polymer with quarternized amino groups, and an anionic polyelectrolyte proceeds regularly. magnified image

The fluorescence quantum yields φ F (n) of oligo[2,5-bis(propyloxy)-1,4-phenylenevinylene]s (1b) reach for the trimer (n = 3) in solution a maximum of 86 %, which is almost twice as high as for the monomer (n = 1) and the octamer or undecamer (n = 8, 11). The latter represent the convergence limit of 46 %. 4-Mono-, 3,4-di-or 3,4,5-trisubstituted terminal phenyl rings in the trimers 6a-f do not lead to calamitic or phasmidic liquid crystals; however, 2,3,4-trisubstitution with IntroductionDue to their interesting electrical, optical and optoelectronic properties, oligo-and poly(1,4-phenylenevinylene)s [OPV and PPV] are a highly attractive class of compounds in organic chemistry and materials science.[1] Already with n Ͼ 3, the parent system 1a is insoluble in organic solvents, so solubilizing alkyl or better alkoxy side chains have to be introduced. Some time ago we prepared the series 1b (n = 1-8, 11, 15) with 2,5-dipropoxy-substituted phenyl rings (Scheme 1). [2][3][4] Increasing numbers n of repeating units in conjugated oligomers lead for various properties P to limiting values which can be matched by the corresponding polymer. This approach can be monotonous, as for the λ max values of absorption and fluorescence of 1b, [2][3][4] but the approach P(n) Ǟ P ϱ can also pass for a certain number nЈ through a maximum and/or a minimum. [1l] An important example is given for the electroluminescence efficiency of 1b which reaches a maximum for n = 3. [5] Earlier studies indicated that the photoluminescence quantum yields φ F should also have a maximum for a certain repeat number n of 1b since φ F = 0.82 for the dimer n = 2 measured in CH 2 Cl 2 is much higher than φ F of a long oligomer chain (φ F ≈ 0.5 for n = 11). [6,7] We determined now the fluorescence quantum yields φ F (n) for the whole series 1b (n = 1-8, 11) and tried to obtain liquid crystals (LC) for those oligomers that have the highest φ F value.[

We present the synthesis and the electrochemical characterization of polymeric electron transport materials, synthesized by polycondensation of substituted triazines and α,ω‐dihaloalkanes. They can be reversibly reduced with the least negative potential at −0.39 V, which is below the reduction potential of oxygen. In addition, the formation of polyelectrolyte multilayers is possible by the electrostatic self‐assembly method. This multilayer formation takes place in a very defined way up to thirty double layers.An example of one of the polymeric triazine electron transport materials synthesized and a schematic diagram of a self‐assembled multilayer film.magnified imageAn example of one of the polymeric triazine electron transport materials synthesized and a schematic diagram of a self‐assembled multilayer film.