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Photophysical and Magnetic Properties in Complexes Containing 3d/4f Elements and Chiral Phenanthroline‐Based Helicate‐Like Ligands
Author(s) -
Speed Saskia,
Pointillart Fabrice,
Mulatier JeanChristophe,
Guy Laure,
Golhen Stéphane,
Cador Olivier,
Le Guennic Boris,
Riobé François,
Maury Olivier,
Ouahab Lahcène
Publication year - 2017
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201601501
Subject(s) - chemistry , crystallography , phosphorescence , ligand (biochemistry) , chiral ligand , luminescence , singlet oxygen , circular dichroism , stereochemistry , photochemistry , enantioselective synthesis , catalysis , fluorescence , oxygen , organic chemistry , biochemistry , physics , receptor , optoelectronics , quantum mechanics
The reactions between the chiral helicene‐like ligand (L) and either Ln(hfac) 3 · 2H 2 O (hfac – = 1,1,1,5,5,5‐hexafluoroacetylacetonate), Ln(tta) 3 · 2H 2 O (tta – = 2‐tenoyltrifluoroacetonate), iron(II) sulfate or chloride, or a combination of them led to the formation of five chiral 4f compounds of formula [HL][Ln(hfac) 4 ] · n CH 2 Cl 2 [Ln = Dy, n = 0.5 ( 1 ) and Ln = Yb, n = 1 ( 2 )], [HL][Ln(tta) 4 ] · n C 6 H 14 [Ln = Dy, n = 0 ( 3 ) and Ln = Yb, n = 2.5 ( 4 )], and [HL] 2 [Yb 8 (hfac) 12 (OH) 12 (O)] · 0.5C 6 H 14 · H 2 O ( 5 ), a chiral 3d complex of formula [Fe(NCS) 2 (L)] · CH 3 NO 2 ( 6 ), and a chiral 3d/4f heterodimetallic compound of formula [Fe(tta)(L)][Dy(tta) 4 ] · 2.5CH 2 Cl 2 ( 7 ). The influence of the nature of the ancillary ligand and the presence or absence of base during the synthesis on the homochiral or heterochiral arrangement of the ligands as well as the dimensionality and nuclearity of the complexes were studied. Ytterbium‐based compounds 2 , 4 , and 5 display near‐infrared (NIR) luminescence under irradiation at λ = 350 nm owing to the 2 F 5/2 → 2 F 7/2 Yb III transition (centered at λ = 1000 nm). Complex 2 displays a second NIR emission at λ = 1278 nm, which is attributed to singlet‐oxygen phosphorescence (a 1 Δ g → X 3 Σ g – ) at both room temperature and 77 K. Dynamic magnetic measurements show an out‐of‐phase signal for the magnetic susceptibility of 7 , which can be depicted as a 3d/4f chiral heterodimetallic single‐molecule magnet.