title: Mn(II)-based porous metal-organic framework showing metamagnetic properties and high hydrogen adsorption at low pressure.
abstract: A Mn(II)-based homometallic porous metal-organic framework, Mn(5)(btac)(4)(μ(3)-OH)(2)(EtOH)(2)·DMF·3EtOH·3H(2)O (1, btac = benzotriazole-5-carboxylate), has been solvothermally synthesized and structurally characterized by elemental analysis, thermogravimetric analysis, and X-ray crystallographic study. 1 is a 3D neutral framework featuring 1D porous channels constructed by {Mn-OH-Mn}(n) chains and btac linkers. Magnetic studies show that 1 is a 3D metamagnet containing 1D {Mn-OH-Mn}(n) ferrimagnetic chains. High-pressure H(2) adsorption measurement at 77 K reveals that activated 1 can absorb 0.99 wt % H(2) at 0.5 atm and reaches a maximum of 1.03 wt % at 5.5 atm. The steep H(2) absorption at lower pressure (98.2% of the storage capacity at 0.5 atm) is higher than the corresponding values of some MOFs (MIL-100 (16.1%), MOF-177 (57.1%), and MOF-5 (22.2%)). Furthermore, activated 1 can adsorb CO(2) at room temperature and 275 K. The adsorption enthalpy is 22.0 kJ mol(-1), which reveals the high binding ability for CO(2). Detailed gas sorption implies that the exposed Mn(II) coordination sites in the activated 1 play an important role to improve its adsorption capacities.
authors.affiliation: College of Chemistry, Liaoning University, Shenyang 110036, P. R. China. ceshzb@lnu.edu.cn
authors.forename: Zheng-Bo
authors.initials: ZB
authors.lastname: Han
authors.forename: Rui-Yun
authors.initials: RY
authors.lastname: Lu
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Liang
authors.forename: Yan-Ling
authors.initials: YL
authors.lastname: Zhou
authors.forename: Qing
authors.initials: Q
authors.lastname: Chen
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Zeng
mesh_terms: D000327:Adsorption; D002264:Carboxylic Acids / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D006859:Hydrogen / Q000302:isolation & purification*; D059346:Magnets / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D016062:Porosity; D011312:Pressure; D014230:Triazoles / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D009942:Organometallic Compounds; D014230:Triazoles; D008345:Manganese; D006859:Hydrogen