Transmetalation in a Ce(III)-phosphoester Crystalline Coordination Polymer with an Exceptionally High Selectivity for...

A novel crystalline coordination polymer containing Ce³⁺ and bis(4-nitrophenyl) phosphate (L), CeL₃ , was synthesized and its unique transmetalation selectivities toward Yb³⁺ and Lu³⁺ in the lanthanide series were evaluated. The relatively large difference in transmetalation selectivity between the neighboring Tm³⁺ and Yb³⁺ species is noteworthy because the reactivities of heavy lanthanides are generally considerably similar. The structural strain of the polymeric framework is likely responsible for this unusual trend. Powder X-ray diffraction analysis indicated that, in the cases of only Yb³⁺ and Lu³⁺ , large differences in their ionic sizes compared to that of Ce³⁺ in the parent framework may induce a structural strain after solid solution formation, while cleavage of the relatively weak Ce-O bond allows the formation of new Yb-O and Lu-O bonds with the incoming Yb³⁺ and Lu³⁺ , respectively. Structural phase transitions likely caused by the heterogeneous nucleation of the Yb- (or Lu-) type phase were also observed.