Über die Farbe der γ,γ′‐Dipyridylium‐halogenide

Emmert, Bruno; Stawitz, J.

doi:10.1002/cber.19230560110

Cited by 15 publications

(11 citation statements)

References 5 publications

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“…[32,33] However, it has been shown that this reaction can also be applied to 2-methylpyridine. [34,35] Thus, N-substituted pyridine-2-thiocarboxamides have been prepared by reaction of 2-methylpyridine with primary amines, [34,35] nitro compounds, [34] or N-substituted formamides [16,36] as amine sources in the presence of sulfur at elevated temperatures Scheme 2. Possible amine sources for the synthesis of N-substituted pyridine-2-thiocarboxamides under the conditions of the WillgerodtϪKindler reaction Eur.…”

mentioning

confidence: 99%

From N‐Substituted Thioamides to Symmetrical and Unsymmetrical 3,4,5‐Trisubstituted 4H‐1,2,4‐Triazoles: Synthesis and Characterisation of New Chelating Ligands

2004

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An improved protocol for the synthesis of N-substituted pyridine-2-thiocarboxamides under the conditions of the Willgerodt−Kindler reaction, employing a catalytic amount of sodium sulfide nonahydrate, has been developed. Following this protocol, eight thioamides carrying aromatic or aliphatic N-substituents have been prepared in good to excellent yields. Condensation of these thioamides or their S-alkylated

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mentioning

confidence: 99%

From N‐Substituted Thioamides to Symmetrical and Unsymmetrical 3,4,5‐Trisubstituted 4H‐1,2,4‐Triazoles: Synthesis and Characterisation of New Chelating Ligands

2004

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“…Similar but weaker spectral effects were found for other donor molecules like EDTA, nitrilotriethanol, or ascorbate. Charge-transfer complexation has been observed and studied for methylviologen (4) itself (see for instance [7][8][9][10][11][12][13][14][15][16][17][18][19]), but the corresponding absorptions are markedly stronger in the VIS for 1 as compared to 4 (with indole acetate, E = 200 and 20, respectively; aqueous solution, 5 mM of each compound; for 4 see also [15]). In view of the numerous studies which have been devoted to the spectroscopic, photophysical, and photochemical properties of 4 (including its use as redox relay species in photochemical light energy storage cycles, see below), MeDAP" (1) and its derivatives represent excellent candidates for The diazapyrenium cations show strongfluorescence (Fig.…”

mentioning

confidence: 99%

Molecular Anion Binding and Substrate Photooxidation in Visible Light by 2,7‐Diazapyrenium Cations

Blacker¹,

Jaźwiński²,

Lehn³

1987

Helvetica Chimica Acta

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The 2,7-diazapyrenium group (DAP2+) combines the features of pyrene, of methylviologen, and of nucleicacid intercalators and may thus present a variety of interesting properties. The cations 1 and 2 and the bis-diazapyrenium species 3 have been synthesized and shown to bind molecular anions like aromatic polycarboxylates, giving rise to pronounced shifts of 'H-NMR signals, modifications of UVjVIS absorption spectra, and quenching of fluorescence. The complexes formed probably have a face-to-face structure, and their stability constants are remarkably high, in particular for the bis-diazapyrenium cation 3 which is susceptible to form intercalative chelate complexes such as 9 (log K, B 3 for 1, up to ca. 7 or more for 3a). Neutral molecules like adenine are also bound, but much less strongly. Visible-light irradiation of Me,DAP2+ (1) in presence of various electron donors, such as EDTA, gives the reduced species Me2DAP+' wich has been characterized by UVjVIS and ESR spectroscopy. The results indicate that Me2DAP2+ (1) functions as a methylviologen analogue, photoactive in visible light. Thus 2,7-diazapyrenium cations are attractive subunits for incorporation into macropolycyclic structures to give photoand electroactive receptor molecules.

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“…Bei den quartaren Ammoniumionen mit einem polaren Substituenten wird dieser reduktiv abgespalten [21,22] NMeaX + e -+ NMeaX;d' NMeaX~d + H+ + e -+ NMe a + HX .…”

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Die Rolle des Elektrolyten bei der kathodischen Hydrodimerisierung des Acrylnitrils

Beck

1968

Ber Bunsenges Phys Chem

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Die Ausbeute an dimerem Produkt bei der kathodischen Hydrodimerisierung des Acrylnitrils ist von der Natur des Leitsalzkations stark abhängig und nimmt in der Reihenfolge N(C2H5)4+, N (C4H9)4+ > N(CH3)4+ > N(C2H5)3H+ > Na+ > Li+ ab, während gleichzeitig die Bildung von Propionitril zunimmt. Messungen des Reduktionspotentials einwertiger Kationen zeigen, daß diese Ionen während des Ablaufs der elektroorganischen Reaktion nicht mit merklicher Geschwindigkeit reduziert werden können. Untersuchungen im Konzentrationsbereich von 45–0,2 Gew.‐% an Tetraäthylammoniumsalz ergaben, daß die Ausbeute an Adipodinitril von der Konzentration der Tetraäthylammoniumsalze praktisch unabhängig ist. Die Strom‐Spannungs‐Kurven der Acrylnitrilhydrodimerisierung werden mit abnehmender Konzentration des Elektrolyten kathodisch verschoben; bei konstantem Potential ist v = d logj/d log c = 0,56 bei NMe4+‐ und v = 0,67 bei NEt4+‐Ionen. Dieser Befund wird mit der Änderung des Spannungsabfalls im diffusen Teil der Doppelschicht gedeutet. Die Adsorption der Kationen in Gegenwart von Acrylnitril ist von untergeordneter Bedeutung. Die Ergebnisse werden an Hand eines ionischen Reaktionsmechanismus diskutiert, wonach nur bei einer bestimmten Konzentration an Protonendonatoren in der Reaktionsschicht vor der Kathode eine maximale Ausbeute an Dimerem erwartet werden kann. – Zu den anderen Funktionen des Elektrolyten, nämlich Leitfähigkeit und Lyotropie, werden ergänzende Messungen mitgeteilt.

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Über die Farbe der γ,γ′‐Dipyridylium‐halogenide

Cited by 15 publications

References 5 publications

From N‐Substituted Thioamides to Symmetrical and Unsymmetrical 3,4,5‐Trisubstituted 4H‐1,2,4‐Triazoles: Synthesis and Characterisation of New Chelating Ligands

From N‐Substituted Thioamides to Symmetrical and Unsymmetrical 3,4,5‐Trisubstituted 4H‐1,2,4‐Triazoles: Synthesis and Characterisation of New Chelating Ligands

Molecular Anion Binding and Substrate Photooxidation in Visible Light by 2,7‐Diazapyrenium Cations

Die Rolle des Elektrolyten bei der kathodischen Hydrodimerisierung des Acrylnitrils

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