An anionic In(Ⅲ)-based metal-organic framework with Lewis basic sites for the selective adsorption and separation of organic cationic dyes

In this paper, a new anionic metal-organic framework, [In（PBPTTBA）][（CH;）;NH;]（BUT-29） has been synthesized through the reaction of tetratopic acid ligand with double Lewis pyridine sites, 4,4’,4’’,4’’’-(4,4’-（1,4-phenylene）bis（pyridine-6,4,2-triyl）) tetrabenzoic acid（H;PBPTTBA） and In（NO;）;·5H;O and fully characterized by single-crystal X-ray diffraction（SXRD）, powder X-ray diffraction（PXRD）,thermogravimetric analysis（TGA）, infrared spectroscopy（IR）, and elemental analysis（EA）. BUT-29 can be used as an efficient adsorbent for the selective removal of organic cationic dyes in N,N0-dimethylformamide（DMF） solution. The adsorption capacities of BUT-29 toward methylene blue and crystal violet at 298 K can reach 1119 mg/g and 832 mg/g, respectively. Moreover, the adsorbed dyes can be released in the DMF solution of LiNO;gradually.