Search results for "Cyclopentadienone"
showing 4 items of 4 documents
Stepwise Lateral Extension of Phenyl‐Substituted Linear Polyphenylenes
2019
Polyphenylenes (PPs) are unique polymers showing high mechanical strength and chemical stability, and having potential applications, for example, in proton transfer and gas‐separation membranes. Moreover, phenyl‐substituted linear PPs can serve as precursors for bottom‐up syntheses of graphene nanoribbons (GNRs), a new class of nanoscale carbon materials that appear promising for nanoelectronics. Notably, lateral extensions of linear PPs with appropriate “branched” phenyl substituents, that is, avoiding spatial overlap of benzene rings in their projections into a plane, can lead to wider GNRs with modulated electronic and optical properties. GNRs with widths up to ≈2 nm are obtained, but sy…
Thermische Cycloadditionen von 1,2‐Dihydropentalen
1989
1,2-Dihydropentalen (1) ist ein gekreuzt konjugiertes 6π-Elektronensystem, das in thermischen Cycloadditionen als 2π-, 4π- oder 6π-Komponente fungieren kann. Es werden die Additionen an Tetraphenylcyclopentadienon (1+23), N-Phenylmaleinimid (1+45) und Tropon (1+68 bzw. 10) beschrieben. Auf der Basis von MNDO-Rechnungen werden Peri-, Regio- und Stereoselektivitat anhand von primaren und sekundaren Orbitalwechselwirkungen diskutiert. Thermal Cycloaddition of 1,2-Dihydropentalene 1,2-Dihydropentalene (1) is a cross-conjugated 6π-electron system, that can act in thermal cycloaddition processes as a 2π, 4π, or 6π component. The addition reactions with tetraphenylcyclopentadienone (1+23), N-pheny…
Herstellung von 1,5‐Cyclooctadiin und 1,3,5,7‐Cyclooctatetraen aus 1,5‐Cyclooctadien
1994
Preparation of 1,5-Cyclooctadiyne and 1,3,5,7-Cyclooctatetraene from 1,5-Cyclooctadiene Bromination of 1,5-cyclooctadiene (1) and stepwise dehydro-bromination first with KOtBu and then with KOtBu/18-crown-6 yields 1,5-cyclooctadiyne (5). A prolonged interaction of the base causes a complete transformation to cyclooc-tatetraene (6). Diyne 5 and even more the intermediate enyne 4 are highly reactive dienophiles. The cycloadducts 10–14 formed with 1,3-cyclohexadiene, carbon disulfide, and tetraphenylcyclopentadienone were isolated and characterized. Treatment of 5 with titanium tetrachloride induces a vigorous polymerization.
CCDC 207301: Experimental Crystal Structure Determination
2004
Related Article: H.Werner, N.Mahr, J.Wolf, A.Fries, M.Laubender, E.Bleuel, R.Garde, P.Lahuerta|2003|Organometallics|22|3566|doi:10.1021/om0302037