Synthesis, Characterization, and Photophysical Properties of Some Heterodimetallic Bisporphyrins of Ytterbium and Transition Metals – Enhancement and Lifetime Extension of Yb³⁺ Emission by Transition‐Metal Porphyrin Sensitization

A series of d‐f heterodimetallic bisporphyrin complexes ( YbZn , YbPd , and YbPt ), in which a Yb III porphyrinate moiety is linked to a transition‐metal porphyrinate moiety by a flexible three‐carbon chain, were synthesized. They were fully characterized by high‐resolution mass spectrometry, 1 H and 31 P NMR spectroscopy, electronic absorption, andfluorescence methods. Variable‐temperature near‐infrared photoluminescence studies showed that the transition‐metal porphyrinate moiety would enhance the ytterbium(III) emission centered at about 998 nm and extend its emission lifetime. YbPd and YbPt showed large two‐photon absorption cross‐section values because of the interaction between the porphyrin units, which caused a loss of centrosymmetry. Optical limiting investigation demonstrated that [Yb(TPP)(L OMe )] and YbPt have comparable performance to C 60 by virtue of their heavy‐metal effect. Our results indicate that these bisporphyrin dimetallic complexes will find valuable applications in the field of nonlinear optics. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)