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Synthetic, Structural, and Spectroscopic Studies of Bis(porphyrinzinc) Complexes Linked by Two‐Atom Conjugating Bridges
Author(s) -
Harper Shan R.,
Pfrunder Michael C.,
Esdaile Louisa J.,
Jensen Paul,
McMurtrie John C.,
Arnold Dennis P.
Publication year - 2015
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201500183
Subject(s) - chemistry , porphyrin , dimer , pyridine , imine , crystallography , ground state , crystal structure , fluorescence , fluorescence spectroscopy , photochemistry , stereochemistry , medicinal chemistry , catalysis , organic chemistry , physics , quantum mechanics
Four Zn II 5,10,15‐triphenylporphyrin (TriPP) complexes meso – meso linked by two‐atom bridges, namely, C 2 H 2 ( 2 ), C 2 ( 3 ), CH=N ( 4 ), and N 2 ( 5 ), were prepared, for comparison of ground‐state inter‐porphyrin conjugation. The X‐ray crystal structure of azoporphyrin 5· py 2 (py = pyridine) was determined: it exhibits a stepped‐offset shape and a porphyrin–azo torsion angle of 34.8°. Some new monoporphyrin starting materials were prepared, and ZnTriPPNH 2 ( 27 ), ZnTriPPCHO ( 23 ), NiTriPPCHO ( 7 ), and ZnTriPPCH 2 CH 2 Ph ( 18 ), as well as the byproduct butadiyne‐linked dimer 26 were characterized by single‐crystal X‐ray crystallography. The conjugation in the dimers was assessed by electronic absorption and steady‐state fluorescence spectroscopy. All show variously split B bands: azoporphyrin 5 clearly has the strongest ground‐state inter‐porphyrin interactions. Imine 4 and azo 5 show strongly quenched fluorescence emission, which indicates the presence of efficient relaxation pathways afforded by the N‐containing linkers.