Influence of Thermally-Induced Structural Transformations over Magnetic and Luminiscence Properties of Tartrate-based Chiral Lanthanide Organic-Frameworks
Ikusi/ Ireki
Data
2020-05-04Egilea
Huizi Rayo, Uxua
Zabala Lekuona, Andoni
Terenzi, Alessio
Cruz, Carlos M.
Cuerva, Juan M.
Rodríguez Diéguez, Antonio
García Martínez, José Angel
Cepeda Ruiz, Javier
Journal of Materials Chemistry C 8(24) : 8243-8256 (2020)
Laburpena
This work reports on the synthesis and characterization of five enantiomeric pairs of isostructural 3D metal-organic
frameworks (MOFs) with the general formula {[Ln2(μ4-tar)2(μ-tar)(H2O)2]·xH2O}n [where Ln(III) = Tb (Tb-L and Tb-D), Dy (Dy-
L and Dy-D), Ho (Ho-L and Ho-D), Er (Er-L and Er-D) and Tm (Tm-L and Tm-D); tar = tartrate (D- or L-) and x = 3 or 4
depending on the counterpart] that present with interesting luminescence and magnetic properties. These MOFs under-go
progressive and reversible dehydration processes upon controlled heating yielding three crystalline phases (Ln-L', Ln-L''
and Ln-L'''). Alternating current magnetic measurements on Tb, Dy and Er-based compounds exhibit field induced singlemolecule
magnet behavior dominated by QTM, which is partially suppressed when diluted on a Y-based matrix. Tartrate
ligands show poor room temperature sensitization of Tb and Dy centers that is enhanced at low temperature (10 K), even
enabling weak Tm-based emission. More interestingly, the dehydration modulates both magnetic and photoluminescent
properties on the basis of both the distortions occurring in the coordination shells and decrease of water molecules acting
as quenchers, respectively, imbuing these materials with potential humidity sensing capacity. Remarkably, the Tb-based
MOF shows circularly polarized luminescence (CPL), being one of the examples of this very scarce family of CPL emitters
reported so far.