Search results for "Annulene"
showing 10 items of 34 documents
Polarizabilities of small annulenes from Cholesky CC2 linear response theory
2004
Using recently developed algorithms based on Cholesky decomposition of two-electron integrals to compute response properties at the correlated level, the static and dynamic (at 589 nm) polarizabilities of [4n + 2]-annulenes (n = 1, 2, 3, 4) have been calculated. The results show that the perpendicular component increases along the series linearly with the number of double bonds. The in-plane static polarizability is also increasing linearly with the area of the aromatic ring in the case of the delocalized species. However, linearity is lost for the localized conformations and for the dynamic polarizability. (C) 2004 Elsevier B.V. All rights reserved.
Unraveling the kinetics and molecular mechanism of gas phase pyrolysis of cubane to [8]annulene
2020
The kinetic and electron density flows are studied theoretically for the gas phase pyrolysis of cubane via its cage opening to reach bicyclooctatriene and then thermal rearrangement of bicyclooctatriene to produce [8]annulene which is the experimentally observed major product. The observed kinetic data at the MN15-L/maug-cc-pVTZ level of theory were in good agreement with the experimental results as compared to the CBS-QB3 method. The cage opening and the thermal rearrangement steps at the experimentally employed temperature of 520 K were exergonic and exothermic. The atmospheric rate constants calculated by means of the RRKM theory show that the cage opening is the rate-determining step. T…
Ir-Catalyzed Cycloaddition of Tribenzocyclyne with Biphenylenes
2021
We demonstrate that Ir-catalyzed C-C bond activation in biphenylenes followed by a reaction with tribenzocyclyne is a suitable method for synthesizing strained and unknown monoadducts with the tetradehydrotetrabenzo[a,c,e,i]cyclododecene scaffold ([12]annulenes). Modification of reaction conditions also furnished [12]annulene products with cis and/or trans double bonds formed by hydrogen transfer. The [9]annulene side product was formed upon the reaction of the benzyl radical with tribenzocyclyne during the Bergman cyclization. All isolated compounds were fully characterized by HRMS, NMR, and X-ray diffraction analysis.
Variation of polarizability in the [4n+2] annulene series: from [22]- to [66]-annulene.
2008
Using correlated ab initio methods, the polarizability of large [4n + 2]-annulenes is determined, showing that there exists an almost linear relation between the exaltation of magnetic susceptibility (a measure of aromaticity) and an equivalent enlargement of polarizability.
CCDC 800716: Experimental Crystal Structure Determination
2011
Related Article: J.Sanseverino, J.-C.Chambron, E.Aubert, E.Espinosa|2011|J.Org.Chem.|76|1914|doi:10.1021/jo102324u
CCDC 2012097: Experimental Crystal Structure Determination
2020
Related Article: Vicente G. Jiménez, Paula Mayorga-Burrezo, Victor Blanco, Vega Lloveras, Carlos J. Gómez-García, Tomáš Šolomek, Juan M. Cuerva, Jaume Veciana, Araceli G. Campaña|2020|Chem.Commun.|56|12813|doi:10.1039/D0CC04489J
CCDC 827036: Experimental Crystal Structure Determination
2011
Related Article: K.Hackeloer, G.Schnakenburg, S.R.Waldvogel|2011|Eur.J.Org.Chem.|2011|6314|doi:10.1002/ejoc.201100918
CCDC 796594: Experimental Crystal Structure Determination
2011
Related Article: K.Hackeloer, G.Schnakenburg, S.R.Waldvogel|2011|Org.Lett.|13|916|doi:10.1021/ol102969k
CCDC 796593: Experimental Crystal Structure Determination
2011
Related Article: K.Hackeloer, G.Schnakenburg, S.R.Waldvogel|2011|Org.Lett.|13|916|doi:10.1021/ol102969k
CCDC 827037: Experimental Crystal Structure Determination
2011
Related Article: K.Hackeloer, G.Schnakenburg, S.R.Waldvogel|2011|Eur.J.Org.Chem.|2011|6314|doi:10.1002/ejoc.201100918