Structure and NIR luminescence of lanthanide(III) complexes with an organic tridentate ligand

Unusual Effect of Minor Change in Ligand Substitution in Modulation of NIR Emission: A Case Study with [L–ZnII–LnIII] Complexes

“…Similarly, in case of the Sm III complex, three bands are absent here in our systems but are found in reported complexes ((i) 4 G 5/2 → 6 F 11/2 , (ii) 4 G 5/2 → 6 F 3/2 , and (iii) 4 G 5/2 → 6 F 13/2 ). , As already mentioned, on change of ethoxy to methoxy substitution in ligand, the Dy III complex, [ Dy1 ] exhibits a new band at 570 nm ( 4 F 9/2 → 6 H 13/2 ). In addition, we have observed two bands for the Er III complexes ( 4 S 9/2 → 4 I 13/2 and 4 S 3/2 → 4 I 15/2 ) that are not available in the literature. ,− …”

“…The antenna linked to the metal center for energy transfer plays a significant role in NIR emission from lanthanide f → f transition (please see Table S1 which tabulates all significant NIR emission data of L–M–Ln type complexes in recent times). Nd III complexes are reported to show antenna dependent NIR emissions. − However, there are many other aspects which we did not find in literature. For example, Pr III complex reveals three transitions that have not been described in the literature ((i) 1 G 4 → 3 H 4 : [ Pr1 ] = 1338 nm, [ Pr2 ] = 1339 nm; (ii) 1 G 4 → 3 H 5 : [ Pr1 ] = 1372 nm, [ Pr2 ] = 1372 nm; and (iii) 1 G 4 → 3 H 6 : [ Pr1 ] = 1407 nm, [ Pr2 ] = 1409 nm).…”

“…The appearance of the last band at 1820 nm ( 4 F 3/2 → 4 I 15/2 ) is particularly rare. While Caillé et al and Yamamoto et al have reported that ∼1820 nm band, however, most of the other reports on Nd luminescence, including ourselves, did not observe the same. ,− Petoud et al reported that luminescence spectra of four different Salophen ligand–Nd 3+ complexes show significant redshift on bromine substitution. The 4 F 3/2 → 4 I 9/2 , 4 F 9/2 → 4 I 11/2 and 4 F 9/2 → 4 I 13/2 transition bands (appearing at 900, 1060, and 1330 nm, respectively) were found to show significant shifts based on bromine substitution on the ligand .…”

Synthesis, crystal structure, and luminescence properties of new binuclear europium and terbium complexes with tubular morphology

“…Recently, many novel ligands and complexes have been designed and synthesized [4]. And much attention has been focused on the crystal structure and luminescent properties of lanthanide organic complexes, such as Er 3+ , Nd 3+ , Yb 3+ , Eu 3+ , Tb 3+ , Sm 3+ and so on [5][6][7][8][9]. But, it is less reported that lanthanide organic complexes have tubular crystal morphology.…”

Fluorescence properties of novel near-infrared phosphor CaSc2O4:Ce3+, Nd3+

“…For example, "antenna" effects have been extensively reported in many Ln 3+ complexes [2,[4][5][6][7][8][9][10][11][12], in which an organic ligand with large extinction coefficient was always involved to absorb light and be excited to its higher energy levels, and then transfer energy to the center Ln 3+ ions to give sensitized f-f emission. This "antenna" effect has been demonstrated to be effective in organic complexes of both visible luminescent Ln 3+ (Ln 3+ = Tb 3+ , Eu 3+ , Sm 3+ ) [4,5,[13][14][15][16][17] and NIR luminescent Ln 3+ (Ln 3+ = Tb 3+ , Eu 3+ , Sm 3+ ) [4,5,13,18].…”