Crystal structure, slow magnetic relaxation behavior and conversion CO2 of a tetranuclear Ho(III)-based complex

A novel Ho-4 complex, namely[Ho-4(NO3)(2)(acac)(4)(L)(2)(CH3OH)(2)]center dot 2CH(3)CN, where H4L=(E)-2-(hydroxymethyl)-2-(((2-hydroxynaphthalen-1-yl)methylene) amino) propane-1,3-diol and acac=acetylacetone, has been constructed by using a polydentate Schiff base ligand (H4L) reacting with Ho(acac)(3)center dot 2H(2)O. X-ray diffraction analysis indicates that complex 1 shows a central symmetric tetranuclear structure. Both eight-coordinated Ho1(III) and Ho2(III) ions possess a distorted triangular dodecahedron geometrical configuration. Complex 1 shows good solvent stability. The magnetic study reveals that complex 1 exhibits a slow relaxation of the magnetization behavior. To our knowledge, complex 1 is a rarely Ho(III)-based complex displaying slow magnetic relaxation behavior under H-dc=0 Oe filed. Interestingly, complex 1 exhibited high catalytic activity and could effectively catalyze the cycloaddition reaction of CO2 with various epoxides.