Ab Initio Study of Energy Transfer Pathways in Dinuclear Lanthanide Complex of Europium(III) and Terbium(III) Ions

Abstract

An ab initio XMCQDPT2/CASSCF study of energy transfer processes in the dinuclear lanthanide complex [(Acac)3Eu(μ-Bpym)Tb(Acac)3] (Acac is acetylacetonate, and Bpym is 2,2'-bipyrimidine) and a corresponding computational procedure are presented. Because ligands in lanthanide complexes weakly interact with each other, the large dinuclear complex bearing seven organic ligands is divided into fragments that reproduce the electrostatic effects of the ions on the electronic and geometrical structure of the ligands. The multireference XMCQDPT2/CASSCF approach is directly applied to these relatively small fragments with reasonable computational cost. The calculated energies of the singlet and triplet excited states agree well with the experiment. Based on the calculated energies, the energy level diagrams of the complex are constructed and intramolecular energy transfer channels are determined.

Triplet‐State Position and Crystal‐Field Tuning in Opto‐Magnetic Lanthanide Complexes: Two Sides of the Same Coin

“…The values are approximately 24 800 (acac − ), 22 700 (tfac − ) and 22 200 cm −1 (hfac − ) (Figure B) . Considering that the Tb 3+ : 5 D 4 level falls at approximately 20 570 cm −1 , the energy differences with the T 1 of the diketonates are suitable for an efficient ligand‐to‐metal ET in all these complexes .…”

“…Considering that the Tb 3+ : 5 D 4 level falls at approximately 20 570 cm −1 , the energy differences with the T 1 of the diketonates are suitable for an efficient ligand‐to‐metal ET in all these complexes . However, although in Tb‐hfac and Tb‐tfac, this ET preferentially takes place from the diketonate, in Tb‐acac, the bpm ligand (T 1 at 23 350 cm −1 ) also plays a role in the sensitisation (Figure S4 in the Supporting Information) . Indeed, a dim Tb 3+ emission was observed at room temperature for Tb‐acac.…”

“…[14] However,a lthough in Tb-hfac and Tb-tfac, this ET preferentially takes place from the diketonate, in Tb-acac, the bpm ligand (T 1 at 23 350 cm À1 )a lso plays ar ole in the sensitisation ( Figure S4 in the Supporting Information). [43] Indeed,adim Tb 3 + emission was observeda tr oom temperature for Tb-acac. The other two complexes featured ab righter emission, Tb-hfac exhibiting a stronger emission intensity compared to Tb-tfac.…”

“…The values are approximately 24 800 (acac À ), 22 700 (tfac À ) and 22 200 cm À1 (hfac À )( Figure 2B). [33,41,43,44] Considering that the Tb 3 + : 5 D 4 level falls at approximately 20 570 cm À1 ,t he energy differences with the T 1 of the diketonatesa re suitable for an efficient ligand-to-metal ET in all these complexes. [14] However,a lthough in Tb-hfac and Tb-tfac, this ET preferentially takes place from the diketonate, in Tb-acac, the bpm ligand (T 1 at 23 350 cm À1 )a lso plays ar ole in the sensitisation ( Figure S4 in the Supporting Information).…”

Synthesis, crystal structure and luminescent properties of lanthanide extended structure with asymmetrical dinuclear units based on 2-(methylthio)benzoic acid

“…Hetero dinuclear complexes are important because they can have combined and/or synergic properties of the different metal ions; however, they are quite difficult to obtained in a controlled manner [15]. Case (i) is quite commonfor benzoato-based complexes with lanthanides [12], whereas case (ii) is rare and were found in complexes of Eu 3 þ and Tb 3 þ with benzoate derivative ligands [13].…”