Modulating the Photophysical Properties of Azamacrocyclic Europium Complexes with Charge-Transfer Antenna Chromophores

Two europium complexes with bis(bipyridine) azamacrocyclic ligands featuring pendant arms with or without pi-conjugated donor groups are synthesized and fully characterized by theoretical calculations and NMR spectroscopy. Their photophysical properties, including two-photon absorption, are investigated in water and in various organic solvents. The nonfunctionalized ligand gives highly water-stable europium complexes featuring bright luminescence properties but poor two-photon absorption cross sections. On the other hand, the europium complex with an extended conjugated antenna ligand presents a two-photon absorption cross section of 45 GM at 720 nm but is poorly luminescent in water. A detailed solvent-dependent photophysical study indicates that this luminescence quenching is not due to the direct coordination of O-H vibrators to the metal center but to the increase of nonradiative processes in a protic solvent induced by an internal isomerization equilibrium.


Published in:
Inorganic Chemistry, 50, 11, 4987-4999
Year:
2011
ISSN:
1520-510X
Keywords:
Laboratories:




 Record created 2012-01-17, last modified 2018-03-17

Postprint:
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)