title: Coordination templated [2+2+2] cyclotrimerization in a porous coordination framework.
abstract: Controlling chemical reactions by the supramolecular confinement effects of nanopores has attracted great attention. Here we show that open metal sites in porous coordination frameworks can constitute more powerful and strict templates for precision syntheses. A Fe(III) dicarboxylate framework functionalized with triangularly arranged metal sites is used to accomplish [2+2+2] cyclotrimerization reactions for organonitrile, alkyne and alkene monomers bearing a geometrically suitable pyridyl group. In situ single-crystal X-ray diffraction facilitates the direct observation of such a coordination templated reaction, before cylcotrimerization, the monomer coordinates at the Fe(III) centre by its pyridyl donor, which forces three unsaturated groups to gather around a position very similar with that of the desired covalent cyclic trimer. After the reaction, the trimers serve as tripodal ligands to perfectly fix the Fe(III) ions and the whole crystal to generate an exceptionally rigid and porous material with large surface area coupled with guest-proof zero thermal expansion.
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry &Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
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, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry &Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
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, China.
authors.forename: Rui-Biao
authors.initials: RB
authors.lastname: Lin
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry &Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Tai-Yang
authors.initials: TY
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry &Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Guang
authors.initials: G
authors.lastname: Shao
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry &Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
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, China.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Chen