Tris‐dipicolinate Lanthanide Complexes: Influence of the Second Hydration Sphere on the Solid‐State Luminescence Properties

Abstract

A series of tris-dipicolinate europium complexes featuring different complexes has been prepared, and their photophysical study has been performed in the solid state highlighting the crucial role of second sphere water molecules. The non-radiative deactivation constant (k nr ) varies significantly with the number of interstitial water molecules and their distance to the europium emitting center. The complex (NBu 4 ) 3 [Eu(DPA) 3 ], featuring the most lipophilic cation, exhibits excellent solubility and remarkable photophysical properties in aprotic solvents.

Nine‐coordinated Eu3+ Dipicolinate Compounds: Different Crystal Structures and Luminescence Properties as a Function of pH

“…All donor atoms originate from three coordinating [DPA] 2− molecules. Several authors have before reported the structure of Na 3 [Eu(DPA) 3 ] ⋅ 14H 2 O [11a,b,d,f,g,12,13h,i] …”

“…The commonly reported lanthanide complexes consist of three [DPA] 2− molecules creating a nine‐coordinated Ln 3+ complex [11] . The reported crystal structure is of Na 3 [Ln(DPA) 3 ] ⋅ 14H 2 O, where three Na + act as the counter ions [11a,b,d,f,g,12] . This system is a common model compound and is described as having a tricapped trigonal prismatic (TTP) structure [11g] .…”

“…The reported crystal structure is of Na 3 [Ln(DPA) 3 ] ⋅ 14H 2 O, where three Na + act as the counter ions [11a,b,d,f,g,12] . This system is a common model compound and is described as having a tricapped trigonal prismatic (TTP) structure [11g] . The model system has been reported for La 3+ ‐Lu 3+ , except for Pm 3+ , Er 3+ , and Tm 3+ [11a,13] .…”

Crystal structures of two SmIII complexes with dipicolinate [DPA]2− ligands: comparison of luminescent properties of products obtained at different pH values

“…The luminescent properties of lanthanide(III) complexes involving the tridentate dipicolinato ligand, [DPA] 2-, have been studied in great detail (Aebischer et al, 2009;Brayshaw et al, 1995;Chauvin et al, 2004;Kim et al, 1998;Kofod et al, 2020;Mondry & Starynowicz, 1995;Murray et al, 1990;Salaam et al, 2022;Zhou et al, 1994). The luminescent characteristics can be explained by the fact that the formed lanthanide(III) complex with three [DPA] 2ligands coordinating to the central lanthanide(III) cation exhibits an almost perfect tricapped trigonal prism (TTP) coordination environment (Albertsson, 1970;Brayshaw et al, 1995;Kim et al, 1998;Li et al, 2019;Murray et al, 1990;Salaam et al, 2022;Zhou et al, 1994). The luminescence properties have been studied in great depth; however, our knowledge of Sm III with [DPA] 2as the ligand is rather limited (Chuasaard et al, 2017;Kumar et al, 2019;Sharif et al, 2016;Viveros-Andrade et al, 2017).…”

A novel stilbazolium derivative crystals of 4-[2-(4-dimethyl amino-phenyl)-vinyl]-1-methyl-pyridinium+ bromide− (DMSB) single crystal: exploration of the growth, molecular structure, linear optical, and third order nonlinear properties

“…16 It has been established that altering the counter-ion results in the enhancement of crystal packing and aligns the dipole as parallel as feasible, which is a successful molecular engineering technique for creating new ionic organic crystals with high NLO efficiency. 17,18 This higher nonlinearity in this derivative is primarily due to the charge transfer mechanism in the cation. The active stilbazolium chromophore in the cation leads to this mechanism through the electron donor and acceptor group (D–π–A).…”