Search results for "Phosphorous acid"

1970

Two mechanisms are feasible in the anionic polymerization of virtually anhydrous formaldehyde initiated by uncharged LEWIS-bases such as tertiary amines and phosphines: 1. Direct initiation with formation of macrozwitterions the conventional mechanism in which an impurity such as water or methylene glycol acts as a cocatalyst. The investigations were carried out mainly by end group analysis. With triethyl amine as initiator the cocatalysis mechanism is the only or, at least, the predominant mechanism (at 20°C in dimethyl formamide). Quaternary ammonium ions – if any – are present in concentrations much below the concentrations of anionic chain ends. The latter were determined by termination…

Morphology control in biphasic hybrid systems of semiconducting materials.

2015

Simple blends of inorganic nanocrystals and organic (semiconducting) polymers usually lead to macroscopic segregation. Thus, such blends typically exhibit inferior properties than expected. To overcome the problem of segregation, polymer coated nanocrystals (nanocomposites) have been developed. Such nanocomposites are highly miscible within the polymer matrix. In this Review, a summary of synthetic approaches to achieve stable nanocomposites in a semiconducting polymer matrix is presented. Furthermore, a theoretical background as well as an overview concerning morphology control of inorganic NCs in polymer matrices are provided. In addition, the morphologic behavior of highly anisotropic na…

Polycondensed nitrogen heterocycles. Part19. Pyrrolo[1,2-f]phenanthridines by pschorr-type cyclization brought about by hypophosphorous acid

1986

Pyrrolo[1,2-f]phenanthridines were prepared in good yields by the diazotization in acetic acid of the amines la,b and subsequent treatment with hypophosphorous acid. The necessity for hypophosphorous acid in the reaction was demonstrated.