title: Supramolecular-jack-like guest in ultramicroporous crystal for exceptional thermal expansion behaviour.
abstract: The dynamic behaviours of host frameworks and guest molecules have received much attention for their great relevance with smart materials, but little has been developed to control or understand the host-guest interplay. Here we show that the confined guest can utilize not only molecular static effects but also bulk dynamic properties to control the host dynamics. By virtue of the three-dimensional hinge-like framework and quasi-discrete ultramicropores, a flexible porous coordination polymer exhibits not only drastic guest-modulation effect of the thermal expansion magnitude (up to 422 × 10(-6) K(-1)) and even the anisotropy but also records positive/negative thermal expansion coefficients of +482/-218 × 10(-6) K(-1). Moreover, single-crystal X-ray diffraction analyses demonstrate that the jack-like motion of the guest supramolecular dimers, being analogous to the anisotropic thermal expansion of bulk van der Waals solids, is crucial for changing the flexibility mode and thermal expansion behaviour of the crystal.
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Hao-Long
authors.initials: HL
authors.lastname: Zhou
authors.affiliation: 1] MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China [2] School of Physical Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai 201210, China.
authors.forename: Yue-Biao
authors.initials: YB
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and 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 and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Chen