Tetra-Aza-Pentacenes by means of a One-Pot Friedländer Synthesis.

Tetra-aza-pentacenes are attractive n-type small molecules for optoelectronic device applications, yet their syntheses are often laborious. Disclosed here is a one-pot Friedländer synthesis of 1,7,8,14-tetraazapentacece (tAP) derivatives (linear and/or bent), fully aromatized in situ despite the absence of an exogenous oxidant. The photophysics of linear tAPs resembles that of regular pentacene though their crystal structures differ. A LUMO energy of -3.71 eV for di-tert-butylanisole-substituted linear tAP is similar to that of the well-known acceptor, C60 .

Near-IR phosphorescent metalloporphyrin as a photochemical upconversion sensitizer.

The phosphorescent metalloporphyrin sensitizer PtTPTNP (TPTNP = tetraphenyltetranaphtho[2,3]porphyrin) has been successfully coupled with perylenediimide (PDI) or rubrene utilized as triplet acceptors/annihilators to upconvert 690 nm incident photons into yellow fluorescence through sensitized triplet-triplet annihilation at overall efficiencies in the 6-7% range while exhibiting exceptional photostability.

Efficient near-infrared polymer and organic light-emitting diodes based on electrophosphorescence from (tetraphenyltetranaphtho[2,3]porphyrin)platinum(II).

The new metalloporphyrin Pt(tptnp), where tptnp = tetraphenyltetranaphtho[2,3]porphyrin, has been prepared and subjected to photophysical and electrooptical device studies. In degassed toluene solution at room temperature Pt(tptnp) features efficient phosphorescence emission with lambda(max) 883 nm with a quantum efficiency of 0.22. The complex has been used as the active phosphor in polymer and organic light-emitting diodes. Polymer light-emitting diodes based on a spin-coated emissive layer consisting of a blend of Pt(tptnp) doped in poly(9-vinylcarbazole) and 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole exhibit near-IR emission with lambda(max) 896 nm, with a maximum external quantum efficiency (EQE) of 0.4% and a maximum radiant emittance of 100 muW/cm(2). Organic light-emitting diodes prepared via vapor deposition of all layers and that feature an optimized multilayer hole injection and electron blocking layer heterostructure with an emissive layer consisting of 4,4'-bis(carbazol-9-yl)biphenyl (CBP) doped with Pt(tptnp) exhibit a maximum EQE of 3.8% and a maximum radiant emittance of 1.8 mW/cm(2). The polymer and organic light-emitting diodes characterized in this study exhibit record high efficiency for devices that emit in the near-IR at lambda >800 nm.

Conjugated polyelectrolyte capsules: light-activated antimicrobial micro "Roach Motels".

Microcapsules consisting of alternating layers of oppositely charged poly(phenylene ethynylene)-type conjugated polyelectrolytes (CPEs) were prepared via layer-by-layer deposition onto MnCO3 template particles followed by dissolution of the template particles using an ethylenediaminetetraacetate solution. The resulting microcapsules exhibit bright-green fluorescence emission characteristics of the CPEs. Strong antimicrobial activity was observed upon mixing of polyelectrolyte capsules with Cobetia marina or Pseudomonas aeruginosa followed by white-light irradiation. It was demonstrated that the materials act as highly effective light-activated micro "Roach Motels" with greater than 95% kill after exposure to approximately 1 h of white light.