Novel Cofacial Porphyrin‐Based Homo‐ and Heterotrimetallic Complexes of Transition Metals. Issue 61 (20th August 2021)

• Record Type: Journal Article
• Authors: Schissler, Christoph; Schneider, Erik K.; Lebedkin, Sergei; Weis, Patrick; Niedner‐Schatteburg, Gereon; Kappes, Manfred M.; Bräse, Stefan
• Is Part Of: Chemistry. Volume 27:Issue 61(2021)
• Page Start: 15202
• Page End: 15208
• Publication Date: 2021-08-20
• Subjects: active site analogue -- carbon monoxide dehydrogenase -- cofacial -- heterotrimetallic -- homotrimetallic -- ion mobility spectrometry -- porphyrin trimers; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202102376
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: We present a straightforward and generally applicable synthesis route for cofacially linked homo‐ and heterotrimetallic trisporphyin complexes. The protocol encompasses synthesising the first aryl‐based, trans‐ o ‐phenylene trisporphyrin starting from pyrrole and benzaldehyde with an overall yield of 3.6 %. It also allows investigating the respective cis ‐isomer as the first conformationally restricted planar‐chiral trisporphyrin. The free‐base ligand was used in subsequent metalation reactions to afford the corresponding homotrimetallic Mn(III)‐, Fe(III)‐, Ni(II)‐, Cu(II)‐, Zn(II)‐ and Pd(II) complexes – additionally, a small adaptation of the protocol resulted in the defined Ni(II)Fe(III)Ni(II) complex in a total yield of 2.3 %. By monitoring Ni(II) insertion into the empty trimeric ligands, we affirmed that the outer porphyrin rings are filled before the internal ring. The molecular species were characterised by 1 H NMR, UV‐Vis, photoluminescence, IR, MS, CID, and high‐resolution IMS measurements. Abstract : A synthesis route for cofacially linked homo‐ and heterotrimetallic trisporphyin complexes starting from pyrrole and benzaldehyde is presented in this work. Besides the novel aryl‐based, trans ‐ o ‐phenylene trisporphyrin, we investigated the respective cis ‐isomer as the first conformationally restricted planar‐chiral trisporphyrin. The homotrimetallic Mn(III)‐, Fe(III)‐, Ni(II)‐, Cu(II)‐, Zn(II)‐ and Pd(II) complexes and the defined Ni(II)Fe(III)Ni(II) heterotrimetalic complex were synthesized, the metal ion insertion process studied and the resulting compounds investigated by e. g. UV‐Vis, photoluminescence or high‐resolution IMS measurements.