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Phase behavior and microstructure formation of rod and coil molecules, which can associate to form hairy-rod polymeric supramolecules, are addressed theoretically. Association induces considerable compatibility enhancement between the rod and coil molecules and various microscopically ordered structures can appear in the compatibility region. The equilibria between microphase-separated states, the coil-rich isotropic liquid and the rod-rich nematic are discussed in detail. In the regime where hairy-rod supramolecules with a high grafting density appear as a result of the association, three phase diagram types are possible depending on the value of the association energy. In the low grafting density regime only the lamellar microstructure is proven to be stable.

Self-organized structure formation in the melt of hairy-rod polymers is analyzed theoretically. It is shown that the interplay between unfavorable repulsive rod-coil interactions and stretching of the side chains is responsible for the appearance of three different microphases: one lamellar and two hexagonal. The first-order phase transitions between these are considered in detail. If the side chains are long enough for the elastic stretching free energy to dominate the repulsive interactions, hexagonally ordered domains of hairy-rod cylindrical brushes are formed. The lamellar phase is shown to be stable for shorter side chains and occupies an important part of the phase diagram. In the intermediate side chain length regime another hexagonally ordered structure appears, characterized by cylindrical micelles with an elongated cross section, containing several hairy-rod polymers.

4,3 "-Diamino-2',6'-diphenyl- or di(4-biphenylyl)p-terphenyl (3a or 3b) and 4-amino-4 "-carboxy-2',6'-diphenyl-p-terphenyl (6) were synthesized through pyrylium salts and used for the preparation of rigid-rod polyamides and polyimides. The polymers were characterized by inherent viscosity, elemental analysis, FT-IR, H-1-NMR, C-13-NMR, W-vis, X-ray, differential scanning calorimetry (DSC)? thermomechanical analysis (TMA), thermal gravimetric analysis (TGA) isothermal gravimetric analysis, and moisture absorption. They were amorphous. All polyamides as well as the polyimide derived from 3b and benzophenonetetracarboxylic dianhydride dissolved in polar aprotic solvents and H2SO4 98%. Polyamide prepared from 6 showed blue fluorescence in dimethylformamide solution. The T(g)s, of polyamides ranged from 235 to 285 degrees C. The polymers possessed excellent thermooxidative stability with no weight loss up to 379-417 degrees C in air.

4,3 "-Diamino-2',6'-diphenyl- or di(4-biphenylyl)p-terphenyl (3a or 3b) and 4-amino-4 "-carboxy-2',6'-diphenyl-p-terphenyl (6) were synthesized through pyrylium salts and used for the preparation of rigid-rod polyamides and polyimides. The polymers were characterized by inherent viscosity, elemental analysis, FT-IR, H-1-NMR, C-13-NMR, W-vis, X-ray, differential scanning calorimetry (DSC)? thermomechanical analysis (TMA), thermal gravimetric analysis (TGA) isothermal gravimetric analysis, and moisture absorption. They were amorphous. All polyamides as well as the polyimide derived from 3b and benzophenonetetracarboxylic dianhydride dissolved in polar aprotic solvents and H2SO4 98%. Polyamide prepared from 6 showed blue fluorescence in dimethylformamide solution. The T(g)s, of polyamides ranged from 235 to 285 degrees C. The polymers possessed excellent thermooxidative stability with no weight loss up to 379-417 degrees C in air.

Simulating protein flexibility is a major issue in the docking-based drug-design process for which a single methodological solution does not exist. In our search of new anti-Alzheimer ligands, we were faced with the challenge of including receptor plasticity in a virtual screening campaign aimed at finding new β-secretase inhibitors. To this aim, we incorporated protein flexibility in our simulations by using an ensemble of static X-ray enzyme structures to screen the National Cancer Institute database. A unified description of the protein motion was also generated by computing and combining a set of grid maps using an energy weighting scheme. Such a description was used in an energy-weighted virtual screening experiment on the same molecular database. Assessment of the enrichment factors from these two virtual screening approaches demonstrated comparable predictive powers, with the energy-weighted method being faster than the ensemble method. The in vitro evaluation demonstrated that out of the 32 tested ligands, 17 featured the predicted enzyme inhibiting property. Such an impressive success rate (53.1%) demonstrates the enhanced power of the two methodologies and suggests that energy-weighted virtual screening is a more than valid alternative to ensemble virtual screening given its reduced computational demands and comparable performance. © 2012 American Chemical Society.