Elektrochemische Synthesen, XIV [1] Radikalkation-Salze des Naphthalins / Electrochemical Syntheses, XIV [1]. Radical Cation Salts of Naphthalene

Fritz, Heinz P.; Gebauer, Helmut; Friedrich, Péter; Ecker, Peter; Artes, R.; Schubert, Ulrich S.

doi:10.1515/znb-1978-0508

Cited by 86 publications

(28 citation statements)

References 15 publications

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“…A sandwich-like structure for the dimeric aromatic π radical cations has been well-established. 25,26 The X-ray structure and the intervalent electron transfer in organic mixed-valence crystals with bridged aromatic radical cations are also reported. 27 In contrast with the two-dimensional porphyrin π-system, fullerenes contain an extensively conjugated three-dimensional π system.…”

Section: Suitable Components Of Efficient Electron Transfer Systemsmentioning

confidence: 99%

New perspective of electron transfer chemistry

2003

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A new perspective of electron transfer chemistry is described for fine control of electron transfer reactions including back electron transfer in the charge separated state of artificial photosynthetic compounds and its synthetic application. Fundamental electron transfer properties of suitable components of efficient electron transfer systems are described in light of the Marcus theory of electron transfer, in particular focusing on the Marcus inverted region, and they are applied to design multi-step electron transfer systems which can well mimic the function of a photosynthetic reaction center. Both intermolecular and intramolecular electron transfer processes are finely controlled by complexation of radical anions, produced in the electron transfer, with metal ions which act as Lewis acids. Quantitative measures to determine the Lewis acidity of a variety of metal ions are given in relation to the promoting effects of metal ions on the electron transfer reactions. The mechanistic viability of metal ion catalysis in electron transfer reactions is demonstrated by a variety of examples of chemical transformations involving metal ion-promoted electron transfer processes as the rate-determining steps, which are made possible by complexation of radical anions with metal ions.

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Section: Suitable Components Of Efficient Electron Transfer Systemsmentioning

confidence: 99%

New perspective of electron transfer chemistry

2003

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“…The radical cation salts of smaller aromatic compounds form columnar structures in which stacks of the disc-like molecules are placed in a fashion leaving channels in which the counterions are found. [15,17] The reason for the formation of segragated dimers in the radical cation salt is not clear. The molecular overlap in such a pair which is shown in Figure 2b differs from the graphite-like arrangement of the parent compound.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Structural Characterization of Hexa-tert-butyl- hexa-peri-hexabenzocoronene, Its Radical Cation Salt and Its Tricarbonylchromium Complex

Enkelmann¹,

Schmelz²,

Müllen³

2000

Chem. Eur. J.

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The hexa-tert-butyl substituted hexa-peri-hexabenzocoronene was synthesized in an overall yield of 83 % from 4-tert-butylphenylacetylene. The key step was the oxidative cyclodehydrogenation of hexa(4-tert-butylphenyl)benzene with anhydrous FeCl 3 in CH 2 Cl 2. The high solubility of hexa-tertbutyl-hexa-peri-hexabenzocoronene in common organic solvents allowed a comprehensive spectroscopic characterization of this compound in solution.Electrochemical oxidation at À 30 8C in the presence of tetrabutylammonium hexafluoroarsenate led to the formation of a stable radical cation salt. Reaction of hexa-tert-butyl-hexa-peri-hexabenzocoronene with an excess of tricarbonyl-(naphthalene)chromium in THF/diox-ane afforded a mixture of mono-and bis-tricarbonylchromium complexes which could be separated by chromatography. The molecular structures of the parent compound, its radical cation salt and its mono-tricarbonylchromium complex were determined by X-ray analysis and discussed in detail. Remarkably, the crystal structures of these compounds are mainly dominated by the formation of dimers of the aromatic cores. Results and DiscussionThe synthesis of 1 b, outlined in Scheme 1, starts with 4-tertbutylphenylacetylene (2) which is coupled with 4-tert-butyliodobenzene (3) to yield di(4-tert-butylphenyl)acethylene (4) (92 %). [11,12] The [Co 2 (CO) 8 ] mediated cyclotrimerization of 4[a] Prof.

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“…The ESR parameters (Table 1) of the five isoelectronic radical ions reflect the structural differences: the pyrazine derivatives (3) and (4) have larger ring-proton and smaller methyl-proton coupling constants as well as higher g-factors than the benzene derivatives ( l ) , (2) and (5).…”

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confidence: 99%