X-ray crystallographic, luminescence and NMR studies of phenacyldiphenylphosphine oxide with the Ln(iii) ions Sm, Eu, Gd, Tb and Dy

Abstract

We report here the characterization in solution (NMR, luminescence, MS) and the solid-state (X-ray crystallography, IR) of complexes between phenacyldiphenylphosphine oxide and five Ln(iii) ions (Sm, Eu, Gd, Tb, Dy). Four single crystal X-ray structures are described here showing a 1 : 2 ratio between the Ln ions Eu, Dy, Sm and Gd and the ligand, where the phosphine oxide ligands are bound in a monodentate manner to the metal center. A fifth structure is reported for the 1 : 2 Eu(NO)-ligand complex showing bidentate binding between the two ligands and the metal center. The solution coordination chemistry of these metal complexes was probed by H,C and P NMR, mass spectrometry, and luminescence experiments. The title ligand has the capability to sensitize Tb, Dy, Eu and Sm leading to metal-centered emission in solutions of acetonitrile and methanol and in the solid state.

Solvent-Dependent Sensitization of Ytterbium and Neodymium via an Intramolecular Excimer

“…Inspired by the work by Platt 12 and Biros, 13 we chose to incorporate the desired 1,1-di(1-pyrenyl) moiety into a phosphoryl acetophenone ligand. Di(1-pyrenyl)phosphoryl acetophenone Pyr 2 POAcH was obtained in two steps (Scheme The emission spectra of the free ligand Pyr 2 POAcH in various solvents are shown in Figure 1.…”

“…After evaporation under reduced pressure, the residue was isolated by flash chromatography on a silica column (hexanes/ethyl acetate = 20/1) to give the product as a white solid (810 mg, 42% yield). 1 H NMR (CDCl 3 , 400 MHz) δ 8.86 (dd, J = 9.2, 4.0 Hz, 2H, CH pyr ), 8.22− 8.17 (m, 6H, CH pyr ), 6H,CH pyr ),4H,CH pyr ),4.20 (dq,J = 9.8,7.0 Hz, 2H, OCH 2 ), 1.44 (t, J = 7.0 Hz, 3H, CH 3 ) ppm; 13 C NMR (CDCl 3 , 101 MHz) δ 135.4 (d,J = 21.6 Hz),133.2 (d,J = 23.5 Hz),132.4 (s),131.4,130.9 (d,J = 1.2 Hz),128.5 (d,J = 5.2 Hz),128.4,128.0 (d,J = 2.7 Hz),127.6,126.1,125.6 (d,J = 9.3 Hz),125.0 (d,J = 2.5 Hz),125.0,124.8,124.8 (d,J = 6.4 Hz),124.7,66.8 (d,J = 21.3 Hz, OCH 2 ), 17.5 (d, J = 8.1 Hz, CH 3 ). 31 P{ 1 H} NMR (CDCl 3 , 162 MHz) δ 99.1 (s) ppm.…”

“…, 7.75 (s), 7.07 (s),6.95 (s) ppm; a13 C NMR spectrum could not be obtained because of the extremely low solubility of the complex; 31 P{ 1 H} NMR (CDCl 3 , 162MHz) δ 22.4 (s) ppm. HRMS for C 120 H 75 NNdO 9 P 32+ ([M +Figure 8.…”

“…ppm; a13 C NMR spectrum could not be obtained because of the paramagnetic nature of the complex; 31 P{ 1 H} NMR (DMSO-d6 , 162 MHz) δ 26.2 (s) ppm. HRMS for C 120 H 72 NYbO 6 P 3 Na 2 2+ ([M + 2Na − thf] 2+ ): calcd, 961.1874; found, 961.1855.…”

Relations between Structural and Luminescence Properties of Novel Lanthanide Nitrate Complexes with Bis-phosphoramidate Ligands

“…Additionally, the lower vibrational frequencies of the PO bonds rather than CO ones leads to a lesser probability to nonradiative quenching of the lanthanide ions’ excited state . The synthesis and X-ray characterization of a high number of lanthanide complexes of phosphine oxides and multifunctional phosphine oxide based ligands have been published so far. It has been proven that from the energy point of view, phosphine oxide ligands have better potential interaction with lanthanides rather than phosphates, amides, and pyridine derivatives …”