Synthesis and characterization of 2′,7′-diarylspiro[cyclopentane-1,9′-fluorene] derivatives

Hydrocarbon ladder polymers with ultrahigh permselectivity for membrane gas separations

Membranes have the potential to substantially reduce energy consumption of industrial chemical separations, but their implementation has been limited owing to a performance upper bound-the trade-off between permeability and selectivity. Although recent developments of highly permeable polymer membranes have advanced the upper bounds for various gas pairs, these polymers typically exhibit limited selectivity. We report a class of hydrocarbon ladder polymers that can achieve both high selectivity and high permeability in membrane separations for many industrially relevant gas mixtures. Additionally, their corresponding films exhibit desirable mechanical and thermal properties. Tuning of the ladder polymer backbone configuration was found to have a profound effect on separation performance and aging behavior.

Synthesis, optical and electrochemical properties of 2-[(9H-fluoren-2-yl)aryl]-1H-benz[d]imidazole and 2,7-bis[(1H-benz[d]imidazol-2-yl)aryl]- 9H-fluorene derivatives

A series of 2-[(9H-fluoren-2-yl)aryl]-1H-benzo[d]imidazoles 11–13 and 2,7-bis[(1H-benzo[d]imidazol-2-yl)aryl]-9H-fluorenes 14–16 containing different linking aromatic units were synthesized in good yields. Their absorption and fluorescence properties were investigated in solution and in the solid state. Most compounds possess good fluorescence-emitting ability with φFL values in the region of 0.31–0.99 in solution and display strong blue emission. Structure–optical behavior characteristics and further details of the electronic properties from cyclic voltammetry measurements and theoretical calculations are discussed.