Related Experiment Video
Updated: Apr 20, 2026
Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Synthesis, structure, and magnetism of non-planar heptanuclear lanthanide(III) complexes
Joydeb Goura1, James P S Walsh, Floriana Tuna
1Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India. vc@iitk.ac.in vc@niser.ac.in.
Abstract:
The reaction of the hydrazone, 2-methoxy-6-(pyridin-2-yl-hydrazonomethyl) phenol (LH) with lanthanide(iii) nitrate salts in the presence of excess triethylamine afforded the heptanuclear Ln(iii) complexes: [Gd7(L)6(μ3-OH)8(NO3)4(H2O)]·(NO3)3·8CH3CN·H2O (), [Tb7(L)6(μ3-OH)8(NO3)4]·(NO3)3·9CH3CN·2CH3OH·3H2O (), [Dy7(L)6(μ3-OH)8(NO3)4(H2O)]·(NO3)3·7CH3CN·3H2O (), [Ho7(L)6(μ3-OH)8(NO3)4]·(NO3)3·11CH3CN·2CH3OH·2H2O () and [Er7(L)6(μ3-OH)8(NO3)4]·(NO3)3·8CH3CN·2CH3OH (). Single crystal X-ray diffraction studies reveal that these complexes are tri-cationic, possessing three nitrate counter anions. The heptanuclear ensemble is non-planar and consists of six [L](-) and eight μ3-OH ligands. These compounds show an interesting structural motif with two incomplete cubes fused to each other through a common Ln(iii) ion. Compound exhibits a magnetocaloric effect, with (-ΔSm(T) = 27.7 J kg(-1) K(-1) at 3 K and under a field change of 0-7 T), while compound shows slow magnetic relaxation at very low temperatures.
More Related Videos
Related Concept Videos
02:42Valence Bond Theory
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly,...
02:57Coordination Number and Geometry
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
02:51Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...