Modeling the Eu(III)-to-Cr(III) Energy Transfer Rates in Luminescent Bimetallic Complexes

There is a growing interest in alternatives to lanthanide ion (Ln(III))-based luminescence sensitizing chromophores for vivo applications, mainly optical biological windows. Transition metals (M) are relevant candidates as they have high absorption rates and emission bands covering wide range of visible near-infrared spectrum. However, despite the importance theoretical models design M–Ln(III) complexes, few contributions devoted efforts elucidating energy transfer (ET) processes between M Ln(III) ions. In this context, we adapted intramolecular (IET) calculate, first time, complexes. A new model was proposed that considers assistance phonons calculation ET rates. As an example, can estimate Eu(III) Cr(III) ions [CrEuL3]6+ complex (where L = 2-{6-[N,N-diethylcarboxamido]pyridin-2-yl}-1,1′-dimethyl-5,5′-methylene-2′-(5-methylpyridin-2-yl)bis [1H-benzimidazole]). The calculated (930–1200 s−1) excellent agreement with experimentally available data (750–1200 when phonon-assisted process considered. Thus, be useful predict explain photophysical properties driven by transition metals.