Supramolecular multichromophoric systems containing photoactive subunits are extensively investigated for both fundamental and applicative reasons. The study of photoinduced energy transfer processes between different components of supramolecular systems is of interest for the understanding of naturally occurring processes in photosynthesis. Potential field of applications for such materials are: (i) the development of energy conversion systems, like electroluminescent devices and dye-sensitized solar cells; (ii) sensory signal amplification; (iii) light-driven photochemical molecular devices and (iv) molecular electronics. In this context, ?-conjugated organic materials are particularly appealing because their photophysical features can be tailored to a large extent by manipulating structures, effective conjugation length, stereochemistry or substituents. Such chemical variations not only control the individual molecular electronic properties of the chromophores, but also alter the collective interactions between them. Among possible polycyclic compounds, the heptacyclic polyarene 10,15-dihydro-5H-diindeno[1,2-?;1',2'-c]fluorene (truxene) has been recognized as a potential starting material for the construction of larger polyarenes.1 Recently, truxene species have been characterized as photoactive cores in multichromophoric systems.2 In this communication we report on the synthesis, optical properties and energy transfer features of a series of transition metal-containing complexes and dyads, based on a truxene core, schematically illustrated below. In this series, the {Ru(bipy)2} and {Os(bipy)2} polypyridine photoactive terminals are coupled to the bridging aromatic truxene rigid linker through ethynyl units. Here, energy transfer from Ru(II) to Os(II) components, and from the truxene core to the terminal metal chromophores is observed. The likely pathways and mechanisms of photoinduced energy transfer processes are discussed.
A Preorganized Truxene Platform for Phosphorescent {Ru(bipy)2} and {Os(bipy)2} Metal Centers
A Barbieri;B Ventura;F Barigelletti;
2009
Abstract
Supramolecular multichromophoric systems containing photoactive subunits are extensively investigated for both fundamental and applicative reasons. The study of photoinduced energy transfer processes between different components of supramolecular systems is of interest for the understanding of naturally occurring processes in photosynthesis. Potential field of applications for such materials are: (i) the development of energy conversion systems, like electroluminescent devices and dye-sensitized solar cells; (ii) sensory signal amplification; (iii) light-driven photochemical molecular devices and (iv) molecular electronics. In this context, ?-conjugated organic materials are particularly appealing because their photophysical features can be tailored to a large extent by manipulating structures, effective conjugation length, stereochemistry or substituents. Such chemical variations not only control the individual molecular electronic properties of the chromophores, but also alter the collective interactions between them. Among possible polycyclic compounds, the heptacyclic polyarene 10,15-dihydro-5H-diindeno[1,2-?;1',2'-c]fluorene (truxene) has been recognized as a potential starting material for the construction of larger polyarenes.1 Recently, truxene species have been characterized as photoactive cores in multichromophoric systems.2 In this communication we report on the synthesis, optical properties and energy transfer features of a series of transition metal-containing complexes and dyads, based on a truxene core, schematically illustrated below. In this series, the {Ru(bipy)2} and {Os(bipy)2} polypyridine photoactive terminals are coupled to the bridging aromatic truxene rigid linker through ethynyl units. Here, energy transfer from Ru(II) to Os(II) components, and from the truxene core to the terminal metal chromophores is observed. The likely pathways and mechanisms of photoinduced energy transfer processes are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
