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A Doubly meso-α Linked N-Confused Porphyrin Tape Silver(III) Complex Comprising an Antiaromatic Pyrrolo[2,3-f]indole
Akito Nakai1, Osamu Iwanaga2, Takayuki Tanaka1,2
1Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
Abstract:
The free base form of doubly meso-α linked N-confused porphyrin (NCP) tape 3 was successfully synthesized via Ir(I) mediated intramolecular coupling. The following silver complexation afforded the Ag(III) complex of doubly meso-α linked NCP tape 4. While 3 exhibited 38π aromatic characters, 4 exhibited not only 18π aromatic NCP-type characteristics but also a decent antiaromatic contribution of 12π pyrrolo[2,3-f]indole segment, as probed by NMR spectra, absorption spectra, and DFT calculations.
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Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...

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