Novel quadridentate salen type triple-decker sandwich ytterbium complexes with near infrared luminescence

Self-assembly of 2-aldehyde-8-hydroxyquinolinate-based lanthanide complexes and NIR luminescence

“…An unexpected ligand H 2 baho in 1 is condensed from tris and ahq in a ratio of (12) 13.0154 (19) 11.6975 (7) 11.6645 (7) 11.6639(7) b (Å) 13.3554 (4) 19.1082 (13) 11.8892 (7) 11.8666 (6) 11.8986(6) c (Å) 21.0908 (8)) 13.590 (3) 12.9448 (7) 12.9115 (5) 1:2, whilst the ligand Hnhm in 2-5 is in an equivalent ratio. Structural analysis indicates the importance of H-bonds and p-p stacking in the structural construction and engineering.…”

“…4). It should be noted that the Yb 3+ ion emission in 5 is not a single sharp band but an envelope of bands arising at the higher energy side (980 nm) of the primary 1006 nm emission band [21,28]. These bands arisen from the crystal-field splitting of the emitting and/or fundamental state are ascribed to the consequence of ligand-field effects [29].…”

“…Especially, it is recently reported that 2-aldehyde-8-hydroxyquinoline could efficiently sensitize Yb 3+ ions, where intriguing NIR photoluminescence has been observed [15][16][17][18]. We have reported the syntheses, structures and NIR luminescence of a series of Nd 3+ and Yb 3+ complexes coordinated with 2-(2 0 -hydroxyphenyl)benzimidazole, and salen-type ligands, respectively [19][20][21][22]. As a continuing attempt for NIR property, we herein present the syntheses, structures of a series of mononuclear lanthanide complexes Ce(baho) 2 ÁEt 2 O (1), Dy(nhm) 2 ClÁ0.5H 2 O (2) and Ln(nhm) 2 ClÁ0.5C 6 H 14 (Ln = Ho (3), Er (4), Yb (5)) ( Fig.…”

Lanthanide coordination compounds with 2,2′-bipyridine-6,6′-dicarboxylate: Synthesis, crystal structure, luminescence and magnetic property

“…2 F 7/2 transition of Yb 3+ ion. This band splits into two bands centered 980, 1022 nm in 6 and at 985, 1005 nm in 11, which result from the ligand-field effect [51][52][53][54]. The absence of the ligand-based emission in the emission spectra of 2, 3, 4, 6, 7, 8, 9 and 11 suggests that the energy transfer from the ligand to the lanthanide center is more effective.…”

Near-infrared (NIR) luminescent homoleptic linear tetranuclear [Ln 4 ((OH) 2 -Salophen) 4 ] (Ln = Nd or Yb) complexes self-assembled from the dihydroxylated Salophen ligand

“…The solvate DMF molecule of 3·DMF, contributes to the stability of the structure, while exhibits no observed hydrogen-bonding interactions with the framework. It is worth noting the linear tetranuclear [Yb 4 ((OH) 2 -Salophen) 4 ] host structure in 3·DMF is distinctively different from binuclear triple-decker Ln 2 (Salen) 3 [17] and trinuclear triple-decker Ln 3 (Salen) 3 complexes [18] from the typical quadridentate Salen-type Schiff-base ligands, and also incomparable to trinuclear triple-decker Ln 3 (Salen) 3 [19], cyclic tetranuclear Ln 4 (Salen) 4 [20] or Ln 4 (Salen) 2 [21] and pentanuclear tetra-decker Ln 5 (Salen) 4 [22] frameworks from the hexadentate Salen-type Schiff-base ligands with the two -OMe groups, where the charge balance just depends on the counter-anions while not the mixed (L) 4− and (H 2 L) 2− coordination modes of four (OH) 2 -Salophen ligands in 3·DMF. As to the bulk purity of the four polycrystalline samples of complexes 2-5, it is convincingly established by PXRD measurements.…”