New photo/electroluminescent europium(III) β-diketonate complex containing a p,p′-disubstituted bipyridine ligand: Synthesis, solid state characterization, theoretical and experimental spectroscopic studies

Unveiling the Relationship between Energy Transfer and the Triplet Energy Level by Tuning Diarylethene within Europium(III) Complexes

“…With the energy level getting lower, T → 5 D y rates increase gradually and reach peaks around 20835–20001 cm –1 , where T → 5 D 0 becomes faster than T → 5 D 1 . Similar phenomena have also been found in other literatures. ,, The reason should be that T → 5 D 1 suffers more hindrance from backward energy transfer than T → 5 D 0 . As shown in Figure , an increasing trend turns up for 5 D 1 → T (orange points in Figure ), whereas 5 D 0 → T (coral points in Figure ) remains unchanged.…”

“…Similar phenomena have also been found in other literatures. 37,69,70 The reason should be that T → 5 D 1 suffers more hindrance from backward energy transfer than T → 5 D 0 . As shown in Figure 5, an increasing trend turns up for 5 D 1 → T (orange points in Figure 5), whereas 5 D 0 → T (coral points in Figure 5) remains unchanged.…”

Theoretical Modeling (Sparkle RM1 and PM7) and Crystal Structures of the Luminescent Dinuclear Sm(III) and Eu(III) Complexes of 6,6,7,7,8,8,8- Heptafluoro-2,2-dimethyl-3,5-octanedione and 2,3-Bis(2-pyridyl)pyrazine: Determination of Individual Spectroscopic Parameters for Two Unique Eu3+ Sites

“… 36 , 37 The semiempirical Sparkle RM1 36 and PM7 37 have proven successful in prediction of the ground state geometries of the lanthanide complexes. The semiempirical models not only predict geometries for mono-, 38 , 39 di-, 40 tri-, and polynuclear lanthanide complexes, 41 , 42 they also can divine it for more complicated structures like lanthanide organic frameworks in a reasonable time. 43 − 45 The theoretical estimation of spectroscopic parameters 46 − 48 for simple mononuclear complexes using single crystal or optimized structure is routinely used.…”

New EuIII Pyromellitic Metal–Organic Framework of Intense Red-Orange Luminescence and High Thermal Stability for Marking in Gunshot Residues

“…Thus, the lanthanide coordination compounds formed may exhibit high quantum emission efficiency, acting as light conversion molecular devices (LCMDs) 10,11 and may be used in the photoluminescent marker field. 12−14 In this context, efficient transfer energy can be achieved by several organic ligands, e.g., phosphonates, 15 β-diketones, 16 and carboxylates. 17 The carboxylate anions can easily react with lanthanide ions (in accordance with the Pearson principle) 18 and form a new class of compounds, called lanthanide metal−organic frameworks (LnMOFs).…”

“…Particularly, in the photoluminescence phenomenon of the lanthanide ions, the low absorption coefficients indicate inefficient excitation, with this limitation being explicated by quantum mechanics selection rules. , This problem is overcome using a strongly absorbing chromophore to sensitize Ln III emission, in a process known as “antenna effect”, which occurs basically in three steps: (i) initial excitation, through the chromophore molecule; (ii) energy transfer to Ln III ions, populating the metal-centered excited state; and (iii) Ln III ion light emission. Thus, the lanthanide coordination compounds formed may exhibit high quantum emission efficiency, acting as light conversion molecular devices (LCMDs) , and may be used in the photoluminescent marker field. − In this context, efficient transfer energy can be achieved by several organic ligands, e.g., phosphonates, β-diketones, and carboxylates . The carboxylate anions can easily react with lanthanide ions (in accordance with the Pearson principle) and form a new class of compounds, called lanthanide metal–organic frameworks (LnMOFs).…”