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Light‐Harvesting Metallosupramolecular Squares Composed of Perylene Bisimide Walls and Fluorescent Antenna Dyes
Author(s) -
You ChangCheng,
Hippius Catharina,
Grüne Matthias,
Würthner Frank
Publication year - 2006
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.200600413
Subject(s) - perylene , quantum yield , fluorescence , photochemistry , trifluoromethanesulfonate , fluorescence spectroscopy , chemistry , spectroscopy , materials science , organic chemistry , optics , physics , quantum mechanics , catalysis
The fluorescent dye 4‐dimethylamino‐1,8‐naphthalimide was incorporated at the bay area of N , N ′‐bispyridyl perylene bisimide to afford a fourfold‐functionalized perylene bisimide ligand. Through self‐assembly directed by metal‐ion coordination, a multichromophore supramolecular entity composed of sixteen dimethylaminonaphthalimide antennas and a perylene bisimide‐walled square core was subsequently constructed from this linear ditopic ligand and 90° metal corner [Pd(dppp)](OTf) 2 (dppp=1,3‐bis(diphenylphosphino)propane; OTf=trifluoromethanesulfonate) in good yield. The isolated metallosupramolecular square was characterized by elemental analysis and 1 H, 13 C, and 31 P{ 1 H} NMR and UV/Vis spectroscopy. Furthermore, by means of 1 H NMR diffusion‐ordered spectroscopy (DOSY) the dimension of this assembly was evaluated by employing a previously reported perylene bisimide ligand and its square assembly as references. The results obtained confirm the square framework of the current assembly. The optical properties of this multichromophore dye assembly were investigated by UV/Vis and steady‐state and time‐resolved fluorescence spectroscopy. It was revealed that light captured by dimethylaminonaphthalimide antennas could be efficiently transported to the perylene bisimide core by a fluorescence resonance mechanism (energy‐transfer efficiency E =95 %), and this resulted in almost exclusive detection of intense perylene bisimide emission, irrespective of the excitation wavelength applied. The present square scaffold containing aminonaphthalimide antenna dyes exhibits more than seven times higher fluorescence quantum yield ( Φ fl =0.37) than a previously reported pyrene‐bearing perylene bisimide‐walled square ( Φ fl =0.05). Thus, this multichromophore square assembly with aminonaphthalimide antenna dyes is an artificial model for the cyclic light‐harvesting complexes in purple bacteria.