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Coordination Chemistry‐Assembled Multicomponent Systems Built from a Gable‐Like Bis‐Porphyrin: Synthesis and Photophysical Properties
Author(s) -
Beyler Maryline,
Flamigni Lucia,
Heitz Valérie,
Sauvage JeanPierre,
Ventura Barbara
Publication year - 2013
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12177
Subject(s) - porphyrin , chemistry , free base , photochemistry , zinc , luminescence , acceptor , fluorescence , crystallography , materials science , organic chemistry , salt (chemistry) , physics , optoelectronics , condensed matter physics , quantum mechanics
Multiporphyrinic assemblies were quantitatively formed, in one step, from a gable‐like zinc( II ) bis‐porphyrin ZnP 2 and free‐base porphyrins bearing pyridyl groups. The different fragments are held together by axial 4′‐N(pyridyl)–Zn interactions. Formation of a macrocycle ZnP 2 •(4′‐ cis DP yP) and a bis‐macrocycle (ZnP 2 ) 2 •( TP yP) is discussed. The macrocycle and the bis‐macrocycle were crystallized and studied by X ‐ray diffraction, which confirmed the excellent complementarity between the various components. Spectrophotometric and spectrofluorimetric titrations and studies reveal high association constants for both multiporphyrinic assemblies due to the almost perfect geometrical match between the interacting units. As expected, energy transfer from the zinc porphyrin component to the free‐base porphyrin quenches the fluorescence of the zinc porphyrin components in both compounds. But while in ZnP 2 •(4′‐ cis DP yP) sensitization of the emission of the free‐base porphyrin was observed, in (ZnP 2 ) 2 •( TP yP) excitation of the peripheral Zn porphyrin units does not lead to quantitative sensitization of the luminescence of the free‐base porphyrin acceptor. An unusual HOMO – HOMO electron transfer reaction from ZnP 2 to the excited TP yP unit was detected and studied.