RESUMO
We describe poly(aryleneethynylene)s (PAE) as powerful sensor cores. We discuss concepts (super quenching, molecular wire effect, multivalency) that were developed using PAEs and also the relationship that connects side chain structure (polar, polyelectrolyte, etc., number of ionic groups per repeat, position) and optical properties such as quantum yields. In the second part of the review we discuss applications of PAEs in their interaction with sensor targets; metal cations, fluoride and other anions, explosives, proteins and whole cells being the target for PAEs, while cationic PAEs have been used for the transfection of eukaryotic cells with RNA.
RESUMO
Two literature-known TIPS-ethynyl-dibromoacenes were prepared and employed to synthesize cyclotrimers by using Yamamoto coupling conditions. Two large, well-soluble starphenes were isolated in good yields. Crystallographic characterization verifies the triangular shape and shows significant differences in crystal packing.
RESUMO
The synthesis of tetracene- and pentacene-annulated norbornadienes, formed through the Diels-Alder reaction of a dehydroacene with cyclopentadiene is reported. Ring-opening metathesis polymerization (ROMP) leads to polymers that are investigated with respect to their physical, optical, and electronic properties by gel permeation chromatography (GPC), UV-vis spectroscopy, and cyclic voltammetry. The pentacene-containing polymer P1 is successfully integrated into an organic field-effect transistor (OFET); the tetracene-containing polymer P2 is integrated into an organic light-emitting diode (OLED).
Assuntos
Naftacenos/química , Compostos de Organossilício/química , Polímeros/síntese química , Reação de Cicloadição , Ciclopentanos/química , Técnicas Eletroquímicas , Polimerização , Polímeros/química , Espectrofotometria Ultravioleta , Transistores EletrônicosRESUMO
Poly(para-phenylene vinylene) (PPV) and its derivatives are important semiconducting polymers for organic electronics. Herein, an alkene metathesis approach to obtain PPVs is reported. Tri(iso propyl)silyl-substituted norbornadienes are employed as solubilizing agents. As PPV precursors divinylbenzene is used for acyclic diene metathesis and paracyclophane diene for a ring-opening metathesis polymerization-type approach. The resulting polymers are analyzed by gel permeation chromatography (GPC), UV-vis, fluorescence, and nuclear magnetic resonance (NMR) spectroscopy. All of the polymers show good solubility in common solvents.
Assuntos
Alcenos/química , Química Orgânica/métodos , Norbornanos/síntese química , Polimerização , Polímeros/síntese química , Polivinil/síntese química , Cromatografia em Gel , Furanos/química , Norbornanos/química , Fenômenos Ópticos , Polímeros/química , Polivinil/química , Espectrometria de Fluorescência , Espectrofotometria UltravioletaRESUMO
Alkene metathesis is a superb methodology. We report the progress using alkene metathesis in the synthesis of polymeric organic semiconductors. Three classes of polymers have been synthesized using acyclic diene metathesis (ADMET) or ring opening metathesis polymerization (ROMP), viz., poly(acetylene)s (PA), poly(arylene-vinylene)s (PAV), and organometallic polymers. For PAs, ROMP of cyclooctatetraenes is best, whereas for PAV, both ADMET and indirect and direct ROMP are viable. Metathesis performs flawlessly with the correct monomers, as molybdenum and particularly the robust Ru carbenes demonstrate. When performing ROMP, one is often rewarded with structurally uniform polymers that can display very low polydispersities. Overall, metathesis is a powerful tool for the preparation of semiconducting polymers.