Characteristic Structures and Photophysical Properties of Nine‐Coordinate Europium(III) Complexes with Tandem‐Connected Tridentate Phosphane Oxide Ligands

Abstract

Structures and photophysical properties of f-block metal complexes with tandem-connected tridentate phosphane oxide ligands, {bis [o-(diphenylphosphoryl) (DPPPO) and Eu(hfa) 3 (DPBTPO) provide characteristic distorted, capped square antiprism structures with nine-coordinate oxygen atoms. The emission properties related to the electric transition are characterized by the emission spectra, the

Seven‐Coordinate Luminophores: Brilliant Luminescence of Lanthanide Complexes with C3v Geometrical Structures

“…The radiative rate constant of Eu(tmh)3(tppo) (kr = 0.7×10 3 ) is slightly larger than that of Eu(hfa)3(tppo)2 (kr = 0.5×10 3 ) in solution. [25] The spectral shape of Eu(tmh)3(tppo) is also different from that of Eu(hfa)3(tppo)2 in solution. We consider that the geometrical structure of Eu(tmh)3(tppo) in solution might be pseudo-eightcoordinate structure.…”

“…The Ln(tmh)3(tppo) exhibited small knr values, although the tBu groups in the complexes are composed of high-vibrational frequency C-H bonds (2950 cm -1 ). [25] High-vibrational C-H bonds generally promote effective thermal relaxation from the excited state of lanthanide complexes. [39] We have suggested that introducing low-vibrational frequency group such as C-F(1200 cm -1 ) instead of C-H was available for suppression of the thermal quenching like Eu(hfa)3(tppo)2.…”

“…kr for the lanthanide complexes with 8-TDH and 9-SAP structures are larger than those of typical 8-SAP structures, based on the Laporte rule related to the transition probability. [24,25] The ideal asymmetric lanthanide complex with a seven-coordination structure would construct a unique monocapped octahedron (7-MCO: C3v, Figure 1d) or monocapped trigonal prism (7-MCTP: C2v, Figure 1e), which would promote the enlargement of kr and Φff. Ideal coordination geometrical structures of a) eight-coordinate square anti-prism, b) eight-coordinate trigonal dodecahedron, c) ninecoordinate monocapped square anti-prism, d) seven-coordinate monocapped octahedron and e) seven-coordinate monocapped trigonal prism.…”

Chiroptical Properties of Nonanuclear Tb(III) Clusters with Chiral Champhor Derivative Ligands

“…The organic ligands also enhance the radiative rate by introducing an asymmetric geometry around the lanthanide ion, effectively [9][10][11][12]. Based on their two strategies for design of the ligands, various types of strong luminescent lanthanide complexes with asymmetric structures have been reported [13,14].…”

Solvent-dependent luminescence of eight-coordinated Eu(III) complexes with bidentate phosphine oxide

“…In order to prepare an intensely luminescent lanthanide complex, a large radiative rate constant based on reducing the geometrical symmetry and a small non-radiative rate constant by introducing low-vibrational frequency organic ligands should be required [16][17][18][19]. Previously, we have reported on two asymmetric Eu(III) complexes with low-vibrational frequency hexafluoroacetylacetonato (hfa) and bidentate phosphine oxide ligands, 4,5-bis(diphenylphosphoryl)-9,9-dimethylxanthene Eu(hfa) 2 (xantpo) 2 , and 4,5-bis(di-tert-butylphosphoryl)-9,9-dimethylxanthene Eu(hfa) 3 (tBu-xantpo) ( Fig.…”