ABSTRACT
N-substituted pyrido[4,3-d]pyrimidines are heterocycles which exhibit the asymmetric hydrogen bonding codes of both guanine and cytosine at 60° angles to each other, such that the molecules self-organize unambiguously into a cyclic hexamer, assembled via 18 intermolecular hydrogen bonds. The synthesis is straightforward and can be concluded in six steps from the commercially available malononitrile dimer. X-ray crystallographic analysis of the supermacrocyclic structure shows an undulating disk with a ca. 10.5 Å cavity, the centers of which do not overlap sufficiently to describe a channel in the solid state. However, AFM, SEM, and TEM imaging in solution reveals the formation of 1D nanostructures in agreement with their self-assembly into rosette supermacrocycles, which then stack linearly to form rosette nanotubes.
Subject(s)
Heterocyclic Compounds/chemical synthesis , Nanotubes/chemistry , Pyrimidines/chemical synthesis , Crystallography, X-Ray , Cytosine/chemistry , Guanine/chemistry , Heterocyclic Compounds/chemistry , Hydrogen Bonding , Models, Molecular , Molecular Structure , Particle Size , Pyrimidines/chemistry , Surface PropertiesABSTRACT
A polymer switching between all RGB colors, black and transmissive states was synthesized. The polymer (PTBT) is soluble, processable, both p- and n-dopable, fluorescent and its properties in entire spectrum offer potential uses in NIR devices, LEDs and solar cells. PTBT possesses almost all properties in a single polymer for optoelectronic applications.
Subject(s)
Polymers/chemistry , Triazoles/chemistry , Fluorescence , Solar Energy , Spectroscopy, Near-InfraredABSTRACT
This report highlights the synthesis of only the second green polymer in the literature, which possesses superior properties over the first: a highly transmissive light blue color in the oxidized state with high optical contrast and excellent switching properties.
