TY - JOUR
T1 - The power of lanthanides
T2 - same composition, but different lanthanides leading to different interesting materials properties, from magnetocalorics to molecular magnets and phosphors
AU - Wilk-Kozubek, Magdalena
AU - Mudryk, Yaroslav
AU - Prodius, Denis
AU - Dolotko, Oleksandr
AU - Ahmed, Sheikh J.
AU - Overgaard, Jacob
AU - Smetana, Volodymyr
AU - Mudring, Anja Verena
PY - 2025/12/1
Y1 - 2025/12/1
N2 - Commonly accepted design concepts for ionic liquids (ILs) state that the constituting ions must be large and carry low, well-dispersed charges. A series of ILs based of pentadeca charged ILs with pentanuclear linear {Ln5} units ([Ln5(C2H5-C3H3N2-CH2COO)16(H2O)8](Tf2N)15 (C3H3N2 = imidazolium moiety, Tf2N = bis(trifluoromethanesulfonyl)amide) with Ln = Er, Ho, Tm) demonstrates that these criteria are not absolute. Highly charged ions can also support IL formation, provided they are sufficiently large. Expanding the series of these unconventional, record pentadeca charged with new lanthanide representatives, led to the discovery of additional unprecedented properties for ILs: The Gd compound exhibits a strong magnetocaloric effect (MCE) in the liquid state with a maximum magnetic entropy change of −ΔSM = −11 J⋅kg−1⋅K−1 at 2 K for Δμ0H = 7 T. Albeit the Dy representative shows slow magnetic relaxation, the relaxation times are not favorable for practical application as a molecular magnet. Lastly, for both the Gd and the Y compound, phosphorescence in the seconds time scale is observed, which is, to the best of our knowledge, the longest ever reported for an IL.
AB - Commonly accepted design concepts for ionic liquids (ILs) state that the constituting ions must be large and carry low, well-dispersed charges. A series of ILs based of pentadeca charged ILs with pentanuclear linear {Ln5} units ([Ln5(C2H5-C3H3N2-CH2COO)16(H2O)8](Tf2N)15 (C3H3N2 = imidazolium moiety, Tf2N = bis(trifluoromethanesulfonyl)amide) with Ln = Er, Ho, Tm) demonstrates that these criteria are not absolute. Highly charged ions can also support IL formation, provided they are sufficiently large. Expanding the series of these unconventional, record pentadeca charged with new lanthanide representatives, led to the discovery of additional unprecedented properties for ILs: The Gd compound exhibits a strong magnetocaloric effect (MCE) in the liquid state with a maximum magnetic entropy change of −ΔSM = −11 J⋅kg−1⋅K−1 at 2 K for Δμ0H = 7 T. Albeit the Dy representative shows slow magnetic relaxation, the relaxation times are not favorable for practical application as a molecular magnet. Lastly, for both the Gd and the Y compound, phosphorescence in the seconds time scale is observed, which is, to the best of our knowledge, the longest ever reported for an IL.
KW - Ionic liquids
KW - Lanthanides
KW - Luminescence
KW - Magnetism
KW - Magnetocalorics
KW - Molecular magnets
KW - Phosphorescence
UR - https://www.scopus.com/pages/publications/105017418240
U2 - 10.1016/j.poly.2025.117798
DO - 10.1016/j.poly.2025.117798
M3 - Journal article
AN - SCOPUS:105017418240
SN - 0277-5387
VL - 282
JO - Polyhedron
JF - Polyhedron
M1 - 117798
ER -