Synthesis and Characterization of Electron-Deficient Asymmetrically Substituted Diarylindenotetracenes.

Electron-deficient asymmetrically substituted diarylindenotetracenes were prepared via a series of Friedel-Crafts acylations, aryl-aryl cross-couplings, and an intramolecular oxidative cyclization to form the indene ring. Single-crystal X-ray experiments showed good π-π overlap with π-π distances ranging from 3.26 to 3.76 Å. Both thermogravimetric analysis and differential scanning calorimetry indicated that asymmetrically substituted indenotetracenes (ASIs) are stable at elevated temperatures. From cyclic voltammetry experiments, HOMO/LUMO energy levels of ASI derivatives were determined to be near -5.4/-4.0 eV. UV/visible absorption spectra showed strong absorption of light between 400 and 650 nm with molar attenuation coefficients from 104 to 105 M-1 cm-1. ASIs were also found to have very low fluorescence quantum yields, less than 4%. Using the solid-state packing determined from the single-crystal X-ray experiments, computational modeling indicated that ASI molecules should favor electron transport.

Morphological, Chemical, and Electronic Changes of the Conjugated Polymer PTB7 with Thermal Annealing.

There is considerable interest in improving the performance of organic optoelectronic devices through processing techniques. Here, we study the effect of high-temperature annealing on the properties of the semiconducting polymer PTB7 and PTB7:fullerene blends, of interest as efficient organic photovoltaic (OPV) devices. Annealing to moderate temperature improves the PTB7 morphology and optoelectronic properties. High-temperature annealing also improves morphology but results in poorer optoelectronic properties. This is a result of side chain cleavage that creates by-products that act as trap states, increasing electronic disorder and decreasing mobility. We further observe changes to the PTB7 chemical structure after thermal cleavage that are similar to those following solar irradiation. This implies that side chain cleavage is an important mechanism in device photodegradation, which is a major "burn-in" loss mechanism in OPV. These results lend insight into side chain cleavage as a method of improving optoelectronic properties and suggest strategies for improvement in device photostability.

The in vivo efficacy and side effect pharmacology of GS-5759, a novel bifunctional phosphodiesterase 4 inhibitor and long-acting ß 2-adrenoceptor agonist in preclinical animal species.

Bronchodilators are a central therapy for symptom relief in respiratory diseases such as chronic obstructive pulmonary disease (COPD) and asthma, with inhaled ß 2-adrenoceptor agonists and anticholinergics being the primary treatments available. The present studies evaluated the in vivo pharmacology of (R)-6-[[3-[[4-[5-[[2-Hydroxy-2-(8-hydroxy-2-oxo-1,2-dihydroquinolin-5-yl)ethyl]amino]pent-1-ynyl]phenyl]carbamoyl]phenyl]sulfonyl]-4-[(3-methoxyphenyl)amino]-8-methylquinoline-3-carboxamide (GS-5759), a novel bifunctional compound with both phosphodiesterase 4 (PDE4) inhibitor and long-acting ß 2-adrenoceptor agonist (LABA) activity, which has been optimized for inhalation delivery. GS-5759 dose-dependently inhibited pulmonary neutrophilia in a lipopolysaccharide (LPS) aerosol challenge model of inflammation in rats with an ED50 ≤ 10 µg/kg. GS-5759 was also a potent bronchodilator with an ED50 of 0.09 µg/kg in guinea pigs and 3.4 µg/kg in dogs after methylcholine (MCh) and ragweed challenges respectively. In cynomolgus monkeys, GS-5759 was dosed as a fine-particle dry powder and was efficacious in the same dose range in both MCh and LPS challenge models, with an ED50 = 70 µg/kg for bronchodilation and ED50 = 4.9 µg/kg for inhibition of LPS-induced pulmonary neutrophilia. In models to determine therapeutic index (T.I.), efficacy for bronchodilation was evaluated against increased heart rate and GS-5759 had a T.I. of 700 in guinea pigs and >31 in dogs. In a ferret model of emesis, no emesis was seen at doses several orders of magnitude greater than the ED50 observed in the rat LPS inflammation model. GS-5759 is a bifunctional molecule developed for the treatment of COPD, which has both bronchodilator and anti-inflammatory activity and has the potential for combination as a triple therapy with a second compound, within a single inhalation device.