Stokvis‐Reaktion, XIX. Klassifizierung der Tripyrrene; Additionen an die Methylenpyrrolinon‐Doppelbindung

Abstract

Synthesen und Elektronenspektren einfacher Vertreter der drei bekannten Tripyrrentypen (A-C) werden beschrieben. Additionen an die Doppelbindung des Methylenpyrrolinons und die entsprechenden Doppelbindungen von Di-, Tri-und Tetrapyrrenen ergeben Chromophorverkurzungen wie sie der Gmelin-Reaktion zugrunde liegen. Als Reagenz fur die Methylenpyrrolinon-Doppelbindung eignet sich besonders Tetrachlor-o-benzochinon. Stokvis Reaction, XIX'). -Classification of Tripyrrenes; Additions to the Methylenepyrrolinone Double BondSyntheses and electronic spectra of simple representatives of the three known types of tripyrrenes (A-C) are described. Additions to the respective double bonds of the di-, tri-and tetrapyrrenes result in a shortening of the chromophore, a process which underlies the Gmelin reaction. Tetrachloro-o-benzoquinone is especially suited as a reagent for the methylenepyrrolinone double bond.Es gibt vier mogliche Dipyrromethen-Strukturen2), von denen drei beschrieben sind; die vierte ist unbekannt3). Klassfiierung der TripyrreneEine analoge Unterteilung der Tripyrrene erscheint, wie sich aus folgendem ergibt, nutzlich. Fur Tripyrrene mit ununterbrochener p-Konjugation sind sechs Strukturen denkbar, von denen jedoch nur die drei Typen A, B, C beschrieben sind. Die Typen A und B wurden fruher einheitlich als A4) charakterisiert; der Typ C ist kurzlich von uns 5.6) f ormuliert worden.

Isolation and Identification of the Urinary Pigment Uroerythrin

“…The NMR spectrum clearly supported the proposed structure (11) (Fig. 2) of the pigment but it also indicated a mixture of two isomeric components.…”

“…On the basis of NMR and mass spectral evidence as well as oxidative degradation the tripyrrole structure (11) (Fig. 2) for uroerythrin dimethyl ester monomethyl ether is proposed.…”

Pillars, Layers, Pores and Networks from Nickeltripyrrins: A Porphyrin Fragment as a Versatile Building Block for the Construction of Supramolecular Assemblies

“…Tripyrrins [12][13][14][15][16][17][18][19][20][21] are short, open-chain oligopyrroles, the coordination properties [22][23][24] of which we have studied as analogues to a series of ring-modified porphyrin variants. [25][26][27] The most pronounced feature of a,w-dimethyltripyrrin ligands is the location of the methyl termini, which block one of the coordination sites of a central metal ion in the N,N,Nplane.…”

Electrochemical investigations of tripyrrin complexes

“…Tripyrroles have been extensively used as intermediates in the synthesis of porphyrins [2] and expanded porphyrins [3]. Even though tripyrroles have been well known for over twenty years [4,5], reports of their transition metals complexing capabilities have remained scarce in the literature and only several complexes like I to IV (Fig. 1) have been obtained [5][6][7][8][9][10].…”

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Electrochemical investigations on divalent transition metal complexes with a conjugated linear tripyrrole ligand, namely 3,4,8,9,13, are reported. This tripyrrin ligand behaves as a tridentate monoanionic ligand and forms a series of neutral metal complexes of the type TrpyMX, where M = Zn(II), Cu(II), Ni(II) Co(II) or Pd(II) and X is a chloride anion (Cl -).

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