Covalently Linked 5, 15‐Diazaporphyrin Dimers: Promising Scaffolds for a Highly Conjugated Azaporphyrin π System. Issue 12 (12th February 2014)

• Record Type: Journal Article
• Authors: Matano, Yoshihiro; Fujii, Daisuke; Shibano, Tarou; Furukawa, Ko; Higashino, Tomohiro; Nakano, Haruyuki; Imahori, Hiroshi
• Is Part Of: Chemistry. Volume 20:Issue 12(2014)
• Page Start: 3342
• Page End: 3349
• Publication Date: 2014-02-12
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201304626
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The first examples of β–β directly linked, acetylene‐bridged, and butadiyne‐bridged 5, 15‐diazaporphyrin dimers have been prepared by palladium‐catalyzed coupling reactions of nickel(II) and copper(II) complexes of 3‐bromo‐10, 20‐dimesityl‐5, 15‐diazaporphyrin (mesityl=2, 4, 6‐trimethylphenyl). The effects of the linking modes and <italic>meso</italic>‐nitrogen atoms on the structural, optical, electrochemical, and magnetic properties of the distributed π systems were investigated by using X‐ray crystallography, UV/Vis absorption spectroscopy, DFT calculations, cyclic voltammetry, and ESR spectroscopy. Both the electronic and steric effects of the <italic>meso</italic>‐nitrogen atoms play an important role in the highly coplanar geometry of the directly linked dimers. The direct β–β linkage produces enhanced π conjugation and electron‐spin coupling between the two diazaporphyrin units.</p> </abstract>