In 2022,Durrant, James P.; Day, Benjamin M.; Tang, Jinkui; Mansikkamaki, Akseli; Layfield, Richard A. published an article in Angewandte Chemie, International Edition. The title of the article was 《Dominance of Cyclobutadienyl Over Cyclopentadienyl in the Crystal Field Splitting in Dysprosium Single-Molecule Magnets》.Product Details of 33100-27-5 The author mentioned the following in the article:
Replacing a monoanionic cyclopentadienyl (Cp) ligand in Dy single-mol. magnets (SMMs) with a dianionic cyclobutadienyl (Cb) ligand in the sandwich complexes [(η4-Cb””)Dy(η5-C5Me4tBu)(BH4)]- (1), [(η4-Cb””)Dy(η8-Pn )K(THF)] (2) and [(η4-Cb””)Dy(η8-Pn )]- (3) leads to larger energy barriers to magnetization reversal (Cb”” = C4(SiMe3)4, Pn = 1,4-di(tri-isopropylsilyl)pentalenyl). Short distances to the Cb”” ligands and longer distances to the Cp ligands in 1-3 are consistent with the crystal field splitting being dominated by the former. Theor. anal. shows that the magnetic axes in the ground Kramers doublets of 1-3 are oriented towards the Cb”” ligands. The theor. axiality parameter and the relative axiality parameter Z and Zrel are introduced to facilitate comparisons of the SMM performance of 1-3 with a benchmark SMM. Increases in Z and Zrel when Cb”’ replaces Cp signposts a route to SMMs with properties that could surpass leading systems. In the experiment, the researchers used 1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5Product Details of 33100-27-5)
1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5) is a member of crown ether Ligands. Crown-ethers are macrocyclic polyethers capable of forming host-guest complexes, especially with inorganic and organic cations. Crown-ethers can incorporate protonated primary amine compounds by formation of ion-dipole bonds with the oxygen atoms of the chiral selector. Crown-ethers have been widely used for the separation of several pharmaceuticals both in aqueous and non-aqueous media. Product Details of 33100-27-5
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem