Thermische Isomerisierung von Indigo

Haucke, G.; Graneß, Gerhard

doi:10.1002/ange.19951070130

Cited by 9 publications

(6 citation statements)

References 10 publications

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“…This behaviour is caused by their rigid structure which prevents changes in geometry of the molecules as a response to solvent polarity both in ground and excited states. The form of the absorption and uorescence bands is similar to the spectra of the naphthyridinedione described by Haucke [18] but are shifted approximately 120 nm to the red due to the larger %- Scheme 2 systems. The distance of 30 to 40 nm between the maxima of absorption and uorescence can also be explained by the rigidity of the molecules and the resulting similarity of the geometries in ground and ®rst excited state.…”

Section: Resultssupporting

confidence: 53%

“…This annelation process was evidenced also by comparison of UV/Vis spectra with those of the known (5H,11H)-dibenzo [b,g] [1,5]naphthyridine-6,12-diones [17]. Recently, the so called epindolidiones have been isolated as products of the thermal isomerization of indigo [18]. In contrast to these oxo compounds, the absorption band of the new arylimino derivatives 4 was bathochromically shifted by about 100 nm.…”

Section: Resultsmentioning

confidence: 99%

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New Indigoid Compounds by Reduction of Bis-Imidoylchlorides of Oxalic Acid – A Further Evidence for Dimeric Isocyanides?

Wenzel

Lehmann

Beckert

et al. 1999

Monatshefte fuer Chemie

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Section: Resultssupporting

confidence: 53%

Section: Resultsmentioning

confidence: 99%

New Indigoid Compounds by Reduction of Bis-Imidoylchlorides of Oxalic Acid – A Further Evidence for Dimeric Isocyanides?

Wenzel

Lehmann

Beckert

et al. 1999

Monatshefte fuer Chemie

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“…Epindolidione is not a derivative but rather an isomer of indigo itself that can be derived directly from indigo while heating the latter material in a vacuum at a temperature of 460 °C. , Alternative routes of synthesis exist also, as described in Section of this Perspective, dealing with chemical synthesis of H bonded semiconductors. We analyzed epindolidione in comparison with its better known counterpart, tetracene, and observed a net superiority of epindolidione in terms of charge transport (hole only in both materials’ cases) and stability to operation in air with both OFET devices unencapsulated, stored in air and operated in air as shown in reference .…”

Section: H Bonded Semiconductors Operational (Electrical)stability In...mentioning

confidence: 99%

“…51 Unfortunately, application of the synthetic scheme proposed by Ainley and Robinson to the preparation of epindolidione, led to low yields 52 and could not practically be extended to the preparation of other substituted epindolidiones. The isomerization from indigo directly to epindolidione has also been carried out thermally and studied theoretically by Haucke and Graness 53,54 while heating indigo at 460 °C in gas phase and vacuum. Although functional, this method is not practical for the preparation of functionalized epindolidiones for research relevant purposes.…”

Section: Chemistry Of Materialsmentioning

confidence: 99%

Stability of Selected Hydrogen Bonded Semiconductors in Organic Electronic Devices

et al. 2019

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The electronics era is flourishing and morphing itself into Internet of Everything, IoE. At the same time, questions arise on the issue of electronic materials employed: especially their natural availability and low-cost fabrication, their functional stability in devices, and finally their desired biodegradation at the end of their life cycle. Hydrogen bonded pigments and natural dyes like indigo, anthraquinone and acridone are not only biodegradable and of bio-origin but also have functionality robustness and offer versatility in designing electronics and sensors components. With this Perspective, we intend to coalesce all the scattered reports on the above-mentioned classes of hydrogen bonded semiconductors, spanning across several disciplines and many active research groups. The article will comprise both published and unpublished results, on stability during aging, upon electrical, chemical and thermal stress, and will finish with an outlook section related to biological degradation and biological stability of selected hydrogen bonded molecules employed as semiconductors in organic electronic devices. We demonstrate that when the purity, the long-range order and the strength of chemical bonds, are considered, then the Hydrogen bonded organic semiconductors are the privileged class of materials having the potential to compete with inorganic semiconductors. As an experimental historical study of stability, we fabricated and characterized organic transistors from a material batch synthesized in 1932 and compared the results to a fresh material batch.

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“…8 In vacuo and at high temperatures (450°C), indigo can be isomerised into tetrahydro-dibenzonaphthyridine-dione 'epindolidione'. 9 Involvement of the extended p-electron-system which is capable of breaking such a symmetry-forbidden [s 2 +s 2 ]process has been discussed in this case.…”

mentioning

confidence: 99%

Dyotropic Rearrangements of Tetraazafulvalenes - A New Approach to Aminosubstituted 1,4,5,8-Tetraazanaphthalenes

Stöckner¹,

Käpplinger²,

Beckert³

et al. 2005

Synlett

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Tetraazafulvalenes 1 rearrange in the presence of Montmorillonite-clay to give strongly fluorescent 1,4,5,8-tetraazanaphthalenes of type 2. This observation agrees with that reported for the cross-conjugated systeme of indigo, thus indicating a dyotropic rearrangement has taken place. Inclusion of the extended p-electronsysteme of 1 should facilitate this symmetry forbidden [s 2 +s 2 ]-process. Based on these results, some reactions of heterofulvalenes and -fulvenes reported in the literature can now be explained by dyotropic rearrangements. The easy rearrangement of 1 in the presence of K10 and DMF opens the way for the synthesis of hard to obtain ring-fused pyrazines of type 2.Dyotropic rearrangements are uncatalyzed processes in which two s-bonds simultaneously undergo an intramolecular migration. 1 This process has been examined quite well in the case of organosilyl and organometallic compounds. 2 Such rearrangements have been widely employed for the stereoselective synthesis of highly substituted butyrolactones, 3 for novel transformations of silyl amides into N-cis-propenyl amides 4 as well as for tandem process from a-aminoaldehydes to aminobutyrolactones. 5In material sciences, the synthetic value of this procedure is emphasised by the direct, base-catalysed isomerisation of 1,4,5,8-tetrathianaphthalene into either tetrathiafulvalene (TTF) or BEDT-TTF. 6 Other authors have interpreted these results in the sense of an initial E1cB mechanism for this rearrangement yielding TTF and 1,4-dithiafulvenes. 7 Electrogenerated dications of tetrathioethylenes are capable to undergo an endocyclic to exocyclic (dyotropic) rearrangement. 8 In vacuo and at high temperatures (450°C), indigo can be isomerised into tetrahydro-dibenzonaphthyridine-dione 'epindolidione'. 9 Involvement of the extended p-electron-system which is capable of breaking such a symmetry-forbidden [s 2 +s 2 ]-process has been discussed in this case.The easy access of heterofulvalenes and -fulvenes together with their indigoid properties has prompted us to report a new isomerisation reaction of tetraazafulvalenes.In the course of derivatisation reactions of these heterofulvalenes, especially at temperatures above 110°C, a yellow; highly fluorescent compound was obtained. Upon isolation, mass spectroscopy indicated the same molecular composition as the starting material (1a, for example). In addition, the NMR data ( 1 H and 13 C) did not show significant differences to the starting compound. However, UV/Vis spectra revealed a clear distinction; the product (2a, for example) shows a significantly shorter wavelength absorption than compound 1a (1a: l max = 528 nm, 2a: l max = 467 nm). X-ray diffraction analysis 10 of a single crystal confirmed that 2a differs from 1a and is based on the structure of tetrakis[arylamino]-tetraazanaphthalene ( Figure 1). Figure 1 Solid state (X-ray) structure of compound 2aVariation of the reaction conditions of this rearrangement of the cross-conjugated derivatives 1 to the heteroaromatic bicycles 2 revealed that the best...

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Thermische Isomerisierung von Indigo

Cited by 9 publications

References 10 publications

New Indigoid Compounds by Reduction of Bis-Imidoylchlorides of Oxalic Acid – A Further Evidence for Dimeric Isocyanides?

New Indigoid Compounds by Reduction of Bis-Imidoylchlorides of Oxalic Acid – A Further Evidence for Dimeric Isocyanides?

Stability of Selected Hydrogen Bonded Semiconductors in Organic Electronic Devices

Dyotropic Rearrangements of Tetraazafulvalenes - A New Approach to Aminosubstituted 1,4,5,8-Tetraazanaphthalenes

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Thermische Isomerisierung von Indigo

Cited by 9 publications

References 10 publications

New Indigoid Compounds by Reduction of Bis-Imidoylchlorides of Oxalic Acid – A Further Evidence for Dimeric Isocyanides?

New Indigoid Compounds by Reduction of Bis-Imidoylchlorides of Oxalic Acid – A Further Evidence for Dimeric Isocyanides?

Stability of Selected Hydrogen Bonded Semiconductors in Organic Electronic Devices

Dyotropic Rearrangements of Tetraazafulvalenes - A New Approach to ­Aminosubstituted 1,4,5,8-Tetraazanaphthalenes

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Dyotropic Rearrangements of Tetraazafulvalenes - A New Approach to Aminosubstituted 1,4,5,8-Tetraazanaphthalenes