Syntheses, Crystal Structures, and Magnetic Properties of Two p-tert-Butylsulfonylcalix[4]arene Supported Cluster Complexes with a Totally Disordered Ln4(OH)4 Cubane Core

Two new sandwich calix[4]arene-supported cluster complexes, [Ln(4)(OH)(4)(TBSOC)(2)(H2O)(4)(CH3OH)(4)]-center dot 4H(2)O (H4TBSOC = p-tert-butylsulfonylcalix[4]arene; Ln = Dy, 1; Ln = Ho, 2), have been prepared and characterized. An X-ray crystallographic study reveals that both complexes contain a holistically disordered [Ln(4)(OH)(4)](8+) cubane cluster core, which is sandwiched between two antiparallel calixarene macrocycles. Magnetic investigations indicate that complex 1 displays slow magnetization relaxation typical for single-molecule magnets in the absence of a static applied dc field, with the Delta E/k(B) parameter of 22.9 K, the largest value for the calixarene-supported pure 4f single-molecule magnets so far, magnetization above whereas complex 2 does not show any relaxation of the magnetization above 2 K.