title: Synthesis and stabilization of a hypothetical porous framework based on a classic flexible metal carboxylate cluster.
abstract: By using pyridyl derivatives 4-cyanopyridine (4-pyCN) or nicotinate (na(-)) as terminal ligands (L(T)) to decorate the flexible trigonal-prismatic trinuclear metal carboxylate M3(μ3-O/μ3-OH)(RCOO)6(L(T))3 clusters, a theoretically predicted uninodal 6-connected flu-e network for [M3(μ3-O/μ3-OH)(bdc)3(L(T))3] (H2bdc = 1,4-benzenedicarboxylic acid) has been realized in three new porous coordination frameworks. The flu-e topology is isomeric to the uninodal 6-connected acs (MIL-88) and tetranodal 6-connected mtn-e (MIL-101) ones observed in the classic metal carboxylate framework materials, but comprises of unique cubic cages which require exceptional conformation for the trinuclear clusters. The weak coordinating 4-pyCN terminal ligands tend to leave the clusters during thermal activation, leading to framework distortion and reduction of the long-range order of the flu-e network, which can only be restored by 4-pyCN instead of other guest molecules. On the other hand, the carboxylate ends of the adjacent na(-) ligands coordinate with additional metal ions to crosslink the coordination networks as new binodal 4,9-connected networks with remarkably enhanced thermal/chemical stability and porosity.
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry & Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China. zhangjp7@mail.sysu.edu.cn.
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Wei
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry & Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China. zhangjp7@mail.sysu.edu.cn.
authors.forename: Jian-Qiang
authors.initials: JQ
authors.lastname: Shen
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry & Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China. zhangjp7@mail.sysu.edu.cn.
authors.forename: Pei-Qin
authors.initials: PQ
authors.lastname: Liao
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry & Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China. zhangjp7@mail.sysu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Xue
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry & Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China. zhangjp7@mail.sysu.edu.cn.
authors.forename: Jie-Peng
authors.initials: JP
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry & Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China. zhangjp7@mail.sysu.edu.cn.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Chen