PDF《sorption behaviours》

ARTICLE Received

10 Sep

2014 | Accepted

21 Jan

2015 | Published

23 Feb

2015 Self-catalysed aerobic oxidization of organic linker in porous crystal for on-demand regulation of sorption behaviours Pei-Qin Liao1, Ai-Xin Zhu1,2, Wei-Xiong Zhang1, Jie-Peng Zhang1 &

Xiao-Ming Chen1 Control over the structure and property of synthetic materials is crucial for practical applications.

Here we report a facile, green and controllable solidCgas reaction strategy for on-demand modi?cation of porous coordination polymer. Copper(I) and a methylene-bridged bis-triazolate ligand are combined to construct a porous crystal consisting of both enzyme-like O2-activation site and oxidizable organic substrate. Thermogravimetry, single- crystal X-ray diffraction, electron paramagnetic resonance and infrared spectroscopy showed that the methylene groups can be oxidized by O2/air even at room temperature via formation of the highly active Cu(II)-O2 ? ? intermediate, to form carbonyl groups with enhance rigidity and polarity, without destroying the copper(I) triazolate framework. Since the oxidation degree or reaction progress can be easily monitored by the change of sample weight, gas sorption property of the crystal can be continuously and drastically (up to

4 orders of magnitude) tuned to give very high and even invertible selectivity for CO2, CH4 and C2H6. DOI: 10.1038/ncomms7350

1 MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China.

2 Faculty of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650092, P. R. China. Correspondence and requests for materials should be addressed to J.-P.Z. (email: [email protected]). NATURE COMMUNICATIONS | 6:6350 | DOI: 10.1038/ncomms7350 | www.nature.com/naturecommunications

1 &

2015 Macmillan Publishers Limited. All rights reserved. C ompared with conventional adsorbents, porous coordina- tion polymers (PCPs) are unique for their diversi?ed and tailorable coordination frameworks1C11. While tailoring structure/property generally refers to design/synthesis of new ligands and frameworks, some PCP prototypes can adopt several different metal ions and/or ligands, providing a rational strategy for adjusting the structure/property, albeit only in a limited degree5,8,12C14. A few of these prototypes can even form mixed- component (solid-solution) crystals with variable concentration/ ratio of functional building blocks, which in principle allows the structure/property to be adjusted more continuously and precisely15,16. However, so far there is no rational strategy to directly monitor/control the composition of solid-solution frameworks during the synthesis process because complicated reaction environments involving solvents and/or liquid reactants are generally required for known direct-synthesis and post- synthetic modi?cation (PSM)3,7,17C21 methods. It should be noted that the reaction time/feeding ratio can be hardly used as a parameter for precise control over the reaction progress/ framework composition, since the two variables have complicated relationships. Single-crystal X-ray diffraction is straightforward for direct visualization of the physical adsorption and chemical reaction events in PCPs22, but retaining the sample single crystallinity after physical/chemical changes is always a great challenge22C26, and crystallography is not a technique for quantitative analysis. If a PCP crystal could react with a gas (O2 is a good yet dif?cult candidate) in the absence of assistant solvent/liquid, the sample weight or gas pressure can serve as an easily measurable parameter directly and linearly associated with its framework composition. The selective and '