Hyperbranched polyvinylsulfi des have been prepared through a facile, metal-free, radical induced "A 2 +B 3 " thiol-yne polymerization of 1,3,5-tris(naphthalylethynyl) benzene and 1,4-dithiolbenzene with three different input ratios. The resulting polymers exhibit excellent optical properties like high transparency and very high refractive index (RI) of up to 1.7839, combined with high thermal stability ( T d5% up to 420 °C) and excellent solution processability. These properties make them ideal candidates as high RI polymeric materials (HRIP) in connection with light out-coupling schemes for organic light-emitting diodes (OLEDs). A series of hyperbranched HRIPs with varying monomer compositions have been compared in their optical properties. Finally, phosphorescent monochrome OLEDs are fabricated on top of HRIP layers to test the compatibility of HRIPs with state-of-the-art OLEDs. The results show that the HRIPs do not deteriorate the performance of the OLEDs while maintaining external quantum effi ciencies of over 20% for phosphorescent red OLEDs. These results open a pathway toward alternative, low-cost, and scalable out-coupling concepts through refractive index matching of the OLED materials and the HRIPs presented.

We report on the growth and characterization of onedimensional\ud (1D) planar all-polymer photonic crystals (PhC) with\ud high dielectric contrast (Dn50.3) prepared by spin coating using\ud hyperbranched polyvinylsulfide polymers (HB-PVS) as high\ud refractive index material and cellulose acetate as low refractive\ud index material. Solution processable HB-PVS show a near ultraviolet\ud absorption inducing an increased refractive index in the\ud visible-near infrared (n51.68, k51000 nm). HBPVS:Cellulose\ud Acetate Distributed Bragg Reflectors show a very clear fingerprint\ud of the photonic band gap possessing the expected polarized\ud dispersion properties as a function of the incidence angle.\ud Moreover, engineered microcavities tuned on the weak fluorescence\ud spectrum of the HB-PVS show directional fluorescence\ud enhancement effects due to spectral redistribution of the emission\ud oscillator strength. The combination of all these properties\ud testifies the high optical quality of the obtained photonic structures\ud thus indicating HB-PVS as an interesting material for the\ud preparation of such PhC. V

Linear and hyperbranched polyvinylsulfides with a high refractive index (nD = 1.68–1.76) have been synthesized by selective mono-addition thiol–yne chemistry employing dithiols and di- and trialkynes.

A powerful variation of traditional radical thiol-yne reaction with diphenylacetylene (DPA)-based starting materials leading to the quantitative and selective formation of the corresponding vinyl sulfides is reported. A variety of different thiols are shown to undergo reaction with DPA and the influence of their structure on reactivity is studied. The results obtained from the model reactions are then used to guide the efficient synthesis of hyperbranched poly(vinyl sulfide) (hb-PVS) systems by employing a dithiol and a trialkyne in an A2 + B3 approach. The polymers obtained show excellent solubility in common organic solvents and exhibit high refractive indices (e.g., 1.70 at 589 nm). The combined ease of processability and potential for cross-linking make these materials very interesting for applications, such as coatings for optical devices. The selective mono-addition thiol-yne reaction on DPA serves not only as a synthetic method for the preparation of PVS but could also be applied to the general modification of acetylene-containing materials.