date:2017-04-18

 Abstract: A series of polyoxometalates (POMs) that incorporate the highest-nuclearity Ln clusters that have been observed in such structures to date (Ln26, Ln=La and Ce) are described, which exhibit giant multishell configurations ( Ln⊂W6⊂Ln26⊂W100). Their structures are remarkably different from known giant POMs that feature multiple Ln ions. In particular, the incorporated Ln–O clusters with a nuclearity of 26 are significantly larger than known high-nuclearity (< 10) ln–o clusters in pom chemistry. furthermore, they also contain the largest number of la and ce centers for any pom reported to date and represent a new kind of rare giant poms with more than 100 watoms. interestingly, the ln26-containing POM can undergo a single-crystal to single-crystal structural transformation in the presence of various transition-metal ions, such as  Cu²⁺, Co²⁺, and Ni²⁺, from an inorganic molecular nanocluster into an inorganic–organic hybrid extended framework that is built from POM building blocks with even highernuclearity La28 clusters bridged by transition-metal complexes.