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Covalently Linked 5,15‐Diazaporphyrin Dimers: Promising Scaffolds for a Highly Conjugated Azaporphyrin π System
Author(s) -
Matano Yoshihiro,
Fujii Daisuke,
Shibano Tarou,
Furukawa Ko,
Higashino Tomohiro,
Nakano Haruyuki,
Imahori Hiroshi
Publication year - 2014
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201304626
Subject(s) - covalent bond , steric effects , conjugated system , chemistry , cyclic voltammetry , acetylene , crystallography , absorption spectroscopy , photochemistry , electrochemistry , palladium , copper , spectroscopy , nitrogen , nickel , stereochemistry , catalysis , organic chemistry , electrode , physics , quantum mechanics , polymer
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 meso ‐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 meso ‐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.