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[40]Nonaphyrin(1.1.1.1.1.1.1.1.1) and Its Heterometallic Complexes with Palladium–Carbon Bonds
Author(s) -
Kamimura Yiho,
Shimizu Soji,
Osuka Atsuhiro
Publication year - 2007
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.200601304
Subject(s) - palladium , porphyrin , chemistry , metal , crystallography , electrochemistry , ring (chemistry) , metal ions in aqueous solution , homo/lumo , ion , bond length , stereochemistry , photochemistry , medicinal chemistry , molecule , crystal structure , catalysis , organic chemistry , electrode
Abstract meso ‐Pentafluorophenyl‐ substituted [40]nonaphyrin(1.1.1.1.1.1.1.1.1) 3 has been prepared by using a stepwise ring‐size‐selective synthesis, and has been reduced with NaBH 4 to [42]nonaphyrin(1.1.1.1.1.1.1.1.1) 5 . Structurally, 3 is characterized by a figure‐of‐eight shape, consisting of a porphyrin‐like tetrapyrrolic segment and a hexaphyrin‐like hexapyrrolic segment, whereas 5 has been found to adopt a distorted nonplanar butterfly‐like shape. In the mono‐metal complexes 6 and 7 , a Zn II or Cu II ion is bound by the porphyrin‐like tetrapyrrolic segment, maintaining the overall structure of 3 . Similarly to 3 , complexes 6 and 7 are interconvertible with the corresponding complexes 9 and 10 through two‐electron reduction with NaBH 4 and oxidation with DDQ. The metal‐free hexaphyrin‐like segments of 6 and 7 have been shown to serve as a suitable platform for the complexation of two palladium ions, providing hetero‐trinuclear metal complexes 11 (Zn II –Pd II –Pd II ) and 13 (Cu II –Pd II –Pd II ) in high yields, in which the Zn or Cu ion resides at the same porphyrin‐like segment, and one Pd ion is bound in an NNCC fashion through double CH bond activation while the other is bound in an NNC fashion with single CH bond activation. Multi‐metal complexes 11 , 12 , and 13 exhibit small electrochemical HOMO–LUMO gaps (<0.6 eV), despite their nonplanar conformations.