Calix[4]arene-Supported Mononuclear Lanthanide Single-Molecule Magnet

Three new single paramagnetic lanthanide-based complexes, [Ln­(L)­(LOEt)] (Ln3+ = Dy3+, Tb3+, and Ho3+), are synthesized with the multidentate calix[4]­arene ligand H2L (H2L = 5,11,17,23-tetrakis­(1,1-dimethylethyl)-25,27-dihydroxy-26,28-dimethoxycalix[4]­arene) and Kläui’s tripodal ligand LOEt– (LOEt– = (η5-cyclopentadienyl)­tris­(diethylphosphito-p)­cobaltate­(III)). All of the complexes have been characterized by single crystal X-ray diffraction analysis, thermal stability, absorption spectra, and magnetization measurements. The magnetic properties and magnetostructural correlation in this seven-coordinated system are investigated. The dysprosium complex 1 shows typical single-molecule magnetic behavior with characteristic magnetic hysteresis loops and the slow relaxation of magnetization.