Lanthanide mixed-ligand complexes of the [Ln(CAPh)₃(Phen)] and [La_xEu_1−x(CAPh)₃(Phen)] (CAPh = carbacylamidophosphate) type. A comparative study of their spectral properties

Abstract

A series of complexes Ln(Pip)3(Phen) (Ln(iii) = La, Ce-Nd, Sm-Lu, Y; HPip (CAPh type ligand) = 2,2,2-trichloro-N-(dipiperidin-1-yl-phosphoryl)acetamide, Phen = 1,10-phenanthroline) has been synthesized. The lanthanum(iii) doped europium(iii) complexes ([LaxEu1-x(Pip)3(Phen)], x = 0.99, 0.95, 0.50) have been obtained by the co-crystallization method. The complexes have been characterized by means of X-ray diffraction, IR, (1)H and (31)P-NMR and absorption spectroscopy. Emission and excitation luminescence spectra were recorded at 295 and 77 K. The lifetime values (τ) for the emission of all europium complexes were determined. The (5)D0 luminescence quantum efficiency is 73-89%. The symmetries of the nearest europium surrounding in pure and doped complexes were evaluated from the Stark splitting of (5)D0-(7)FJ transitions. Crystal structures of [Ln(Pip)3(Phen)] (Ln = Nd (1), Eu (2) and Tb (3)) have been determined. Lattice parameters of the [Ln(Pip)3(Phen)] (Ln = Tb, Yb) and the doped [LaxEu1-x(Pip)3(Phen)] (x = 0.99, 0.95, 0.50) complexes have been measured. The presence of four polymorphs within a number of rare earth elements has been estimated: two in triclinic (Ln1 = La, Nd; Ln2 = Eu), one in the monoclinic (Ln3 = Tb) and one in the rhombic (Ln4 = Tb, Yb) symmetry. Complex 3 can be obtained in two crystal modifications: monoclinic and orthorhombic ones.

Probing Optical Anisotropy and Polymorph‐Dependent Photoluminescence in [Ln2] Complexes by Hyperspectral Imaging on Single Crystals

“…7 F 2 Eu 3 + transition was observedi n[ Eu(pip) 3 (phen)] when compared to lanthanum-doped europiumc ompounds. [67] Furthermore,e mission intensity enhancement was induced by symmetry lowering in heterometallic TbÀPt complex ([Tb 2 Pt 3 (SAc) 12 (H 2 O) 2 ]). [68] In contrast to these studies, the here observed polymorph-specific spectralf eatureso f1-3 cannot be ascribed to the introduction of guest ions or external forces, thus their origin must be related to the complexes' intrinsic crystal structures.…”

Tris(N-{bis[methyl(phenyl)amino]phosphoryl}benzenesulfonamidato-κ2O,O′)(1,10-phenanthroline-κ2N,N′)lanthanum(III)

“…The mean average of all La-O bond lengths is 2.476 Å . The La-N distances are with 2.699 (3) and 2.700 (3) Å (mean value 2.693 Å ) shorter than those previously obtained for a 1,10-phenanthrolinate lanthanum (III) complex with hexafluoroacetylacetonate (2.747-2.782 Å ; Rogachev et al, 2005) and longer than La-N bonds in a carbacylamidophosphate ligand complex (2.601-2.635 Å ; Litsis et al, 2015;Sokolnicki et al, 1999).…”

“…The set of the angles between pairs of the faces intersecting along the type b edges (shown in Fig. 2) allows us to assign a distorted bicapped trigonal-prismatic environment ( 1 = 9.48 , 2 = 18.48 , 3 = 43.57 , 4 = 44.89 , ' 1 = 12.47 , ' 2 = 16.05 ) similar to that of the Tb(Pip) 3 (Phen) mixed-ligand complex with 2,2,2-trichloro-N-(dipiperidin-1-ylphosphoryl)acetamide, HPip (Litsis et al, 2015).…”

Spectroscopy and structure of [LnL3bipy] and [LnL3phen] complexes with CAPh type ligand dimethylbenzoylamidophosphate

“…Oscillator strength values P( Â 10 8 ) of hypersensitive 4 I 9/2 -4 G 5/2 , 2 G 7/2 transition for Nd1, Nd2 and related Nd III complexes [11,12]. and at 345 nm (for Eu2).…”