Cyclopent[fg]acepyrylene, cyclopent[jk]acepyryiene and cyclopent[mn]acepyrylene: novel C20H10 cyclopenta-fused polycyclic aromatic hydrocarbons

Sarobe, Martín; Flink, Simon; Jenneskens, Leonardus W.; Poecke, Bart L. A. van; Zwikker, Jan W.

doi:10.1039/c39950002415

Cited by 37 publications

(40 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ϫ yrylene (28, 6%, C 20 H 10 ), [25] cyclopenta[cd]pyrene (29, 7%, Column chromatography was performed on Merck Kieselgel 60 silica (230Ϫ400 ASTM). Ϫ Melting points were uncorrected.…”

Section: Methodsmentioning

confidence: 99%

Flash Vacuum Thermolysis of Acenaphtho[1,2-a]acenaphthylene, Fluoranthene, Benzo[k]- and Benzo[j]fluoranthene – Homolytic Scission of Carbon-Carbon Single Bonds of Internally Fused Cyclopenta Moieties atT ≥ 1100 °C

et al. 1999

Self Cite

View full text Add to dashboard Cite

Flash vacuum thermolysis (FVT, 1000 °C ≥ T ≥ 1200 °C) of acenaphtho[1,2‐a]acenaphthylene (3, C22H12) gave the C22H12 cyclopenta‐fused polycyclic aromatic hydrocarbon (CP‐PAH) acenaphtho[1,2‐e]acenaphthylene (4), cyclopenta[cd]perylene (5) and cyclopenta[def]benzo[hi]chrysene (6). Whereas the formation of 4 is explained by a ring contraction/ring expansion rearrangement of 3, the identification of 5 and 6 suggests that 3 also undergoes homolytic scission of a five‐membered ring's Carbon‐Carbon single bond furnishing the transient diradical intermediate 7. Ring closure of 7to form 8 after rotation around the Carbon‐Carbon single bond of the intact five‐membered ring followed by hydrogen shifts will give 6. The latter can rearrange subsequently into 5by ring contraction/ring expansion. The structural assignment of 4 and 5 was supported by independent FVT of 6,12‐bis(1‐chloroethenyl)chrysene (14) and 3‐(1‐chloroethenyl)perylene (23), respectively. FVT of 14 (900–1200 °C) gave in a consecutive process 6,12‐bis(ethynyl)chrysene (15), 9‐ethynylbenz[j]acephenanthrylene (16) and bis(cyclopenta[hi,qr])chrysene (17). Although at T ≥ 900 °C 17 selectively rearranges into 4 by ring contraction/ring expansion, at 1200 °C the latter is converted into 5 presumably via a diradical intermediate obtained by homolytic scission of a single Carbon‐Carbon bond of a five‐membered ring. FVT of 23 gave in situ 3‐ethynylperylene (25), which at 1000 °C is nearly quantitatively converted into 5. The propensity of internal cyclopenta moieties to undergo homolytic scission of a five‐membered ring′s Carbon‐Carbon single bond was corroborated by independent FVT of benzo[k]‐ (11) and benzo[j]fluoranthene (12). Previously unknown thermal pathways to important (CP)‐PAH combustion effluents are disclosed at T ≥ 1000 °C.

show abstract

“…Ϫ yrylene (28, 6%, C 20 H 10 ), [25] cyclopenta[cd]pyrene (29, 7%, Column chromatography was performed on Merck Kieselgel 60 silica (230Ϫ400 ASTM). Ϫ Melting points were uncorrected.…”

Section: Methodsmentioning

confidence: 99%

Flash Vacuum Thermolysis of Acenaphtho[1,2-a]acenaphthylene, Fluoranthene, Benzo[k]- and Benzo[j]fluoranthene – Homolytic Scission of Carbon-Carbon Single Bonds of Internally Fused Cyclopenta Moieties atT ≥ 1100 °C

et al. 1999

Self Cite

View full text Add to dashboard Cite

show abstract

“…The computed AEAs show that CP-PAHs represent an interesting class of electron acceptors. Since CPPAHs are readily accessible [1,2,9,10,18] and their AEAs can be enhanced further by substitution of the perimeter hydrogens [32,33], (functionalized) CP-PAHs are timely synthetic targets for novel n-type materials, viz. strong oxidants.…”

Section: Discussionmentioning

confidence: 99%

“…This is of interest since CP-PAHs have been identified as prevalent environmental pollutants that are invariably generated during incomplete combustion processes [8]. Recently, the dicyclopentapyrenes 7 and 8 [9,10] (Fig. 1) were unexpectedly found to exert direct-acting mutagenicity in bacterial assays [11].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Gas phase adiabatic electron affinities of cyclopenta-fused polycyclic aromatic hydrocarbons

Todorov

Koper

Lenthe

et al. 2008

Chemical Physics Letters

Self Cite

View full text Add to dashboard Cite

The B3LYP/DZP++ adiabatic electron affinity (AEA) of nine (non)-alternant polycyclic aromatic hydrocarbons are reported and discussed. Calculations became feasible for molecules this size by projecting out the near-linearly dependent part of the one-electron basis. Non-alternant PAH consisting of an alternant PAH core modified by peri-annulation with unsaturated five-membered rings (CP-PAHs) possess markedly enhanced AEAs.

show abstract

“…Pyracylene is also a prototype for a series of molecules: several authors have commented that the photophysical properties of larger polycyclic aromatic hydrocarbons containing 5-membered rings are very different to those without, particularly the characteristic lack of fluorescence [107][108][109][110] from S 1 , 'anomalous' emission 111 from S 2 and reduced resolution 112 of vibrational fine structure. Part of the reason for studying pyracylene is to benchmark approximations to CASSCF that could be used for studying these larger systems.…”

Section: Pyracylenementioning

confidence: 99%

CASSCF calculations for photoinduced processes in large molecules: Choosing when to use the RASSCF, ONIOM and MMVB approximations

Bearpark

Ogliaro

Vreven³

et al. 2007

Journal of Photochemistry and Photobiology A: Chemistry

View full text Add to dashboard Cite

In this article, we compare and contrast the RASSCF, ONIOM and MMVB electronic structure methods for calculating relaxation paths on potential energy surfaces of the excited states of large molecules, and for locating any resulting conical intersections at which nonadiabatic decay can take place. Each method is treated here as an approximation to CASSCF, which we choose as our reference level of theory, but which becomes prohibitively expensive computationally for large molecules. Both MMVB and ONIOM are hybrid computational methods -combining different levels of theory in an energy plus derivatives calculation at a particular molecular geometry -but they differ fundamentally in that MMVB is a hybrid-atom method, whereas ONIOM is a hybrid-molecule method. We explain this distinction through four representative applications: the photostability of pyracylene (studied with CASSCF, RASSCF, MMVB); large geometry changes in the singlet excited states of triangulene (studied with MMVB); a model for interstitial nickel defects in a synthetic diamond lattice (studied with ONIOM CAS:UFF); and the photochemical [4+4] cycloaddition of cyclohexadiene to naphthalene (studied with ONIOM CAS:MMVB). We show that each method is more appropriate for a particular type of photochemical problem. This article is part perspective, part review, and contains new results for three multi-state or photoinduced processes in complex systems.

show abstract

Cyclopent[fg]acepyrylene, cyclopent[jk]acepyryiene and cyclopent[mn]acepyrylene: novel C20H10 cyclopenta-fused polycyclic aromatic hydrocarbons

Cited by 37 publications

References 7 publications

Flash Vacuum Thermolysis of Acenaphtho[1,2-a]acenaphthylene, Fluoranthene, Benzo[k]- and Benzo[j]fluoranthene – Homolytic Scission of Carbon-Carbon Single Bonds of Internally Fused Cyclopenta Moieties atT ≥ 1100 °C

Flash Vacuum Thermolysis of Acenaphtho[1,2-a]acenaphthylene, Fluoranthene, Benzo[k]- and Benzo[j]fluoranthene – Homolytic Scission of Carbon-Carbon Single Bonds of Internally Fused Cyclopenta Moieties atT ≥ 1100 °C

Gas phase adiabatic electron affinities of cyclopenta-fused polycyclic aromatic hydrocarbons

CASSCF calculations for photoinduced processes in large molecules: Choosing when to use the RASSCF, ONIOM and MMVB approximations

Contact Info

Product

Resources

About