Template Synthesis of Alkyl‐Substituted Metal Isocorroles. Issue 19 (15th June 2016)

• Record Type: Journal Article
• Authors: Hoffmann, Martin; Cordes, Birte; Kleeberg, Christian; Schweyen, Peter; Wolfram, Benedikt; Bröring, Martin
• Is Part Of: European journal of inorganic chemistry. Issue 19(2016)
• Page Start: 3076
• Page End: 3085
• Publication Date: 2016-06-15
• Subjects: Template synthesis -- Macrocycles -- Porphyrinoids -- NIR absorption -- Electrochemistry; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201600419
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : Five metal complexes of 10, 10‐dimethylisocorrole ligands with full β‐pyrrolic substitution is have been synthesized. The preparation of nickel(II), palladium(II), and copper(II) complexes was achieved by metal‐templated oxidative macrocyclization of tetrapyrrolic 5, 15‐biladiene precursors. The reaction conditions for successful macrocycle formation in yields of 18–32 % depended strongly on the type of metal ion used. In the case of palladium, three different macrocyclic products were observed by varying the cyclization protocol. The ring‐contracted metal 10‐isocorroles were fully characterized by single‐crystal X‐ray diffraction, optical and resonance spectroscopy, and electrochemical methods. All the compounds belong to the class of nonaromatic porphyrinoids and their structural and spectroscopic properties as well as their redox behavior were found to show the characteristic features of both ring‐contracted aromatic porphyrinoids and linear tetrapyrrole complexes. Abstract : Broken conjugation is the most noteworthy structural feature of isocorroles. The loss of aromaticity of this ring‐contracted porphyrinoid results in intense NIR absorption bands. The gem ‐dimethyl substitution at the meso position ensures sufficient stability for these polyenic compounds, which form metal complexes of Ni, Cu, and Pd through different template‐based synthetic protocols.