Dimeric scandium(III) and monomeric lanthanide(III) complexes with perfluoropropane-1,3-disulfonates as counter anions for Lewis acid catalysis

A novel scandium(III) complex with disulfonates as counter anions, [Sc(μ-OH)(H2O)5]2[O3S(CF2)3SO3]2 (5), was prepared from scandium oxides (Sc2O3) and perfluoropropane-1,3-disulfonic acid (1, HO3SCF2CF2CF2SO3H). By X-ray analysis, 5 was found to be a μ-OH-bridged dimeric structure bearing two perfluoropropane-1,3-disulfonates without bonding to scandium(III) centers. A series of lanthanide(III) complexes were also prepared from 1 and lanthanide oxides (Ln2O3; Ln = La, Nd, Sm, and Gd). In sharp contrast to the dimeric scandium(III) complex, the corresponding lanthanide(III) complexes had monomeric structures. Interestingly, the dimeric scandium(III) complex, but not the monomeric lanthanide complexes, with perfluoropropane-1,3-disulfonates served as an efficient Lewis acid catalyst for the hydrolysis of esters.