A new iodiplumbate polymer [（AOD）（Pb216）]n 1 （AOD = O-protonated 4-azonia-7- oxaspiro（4,5） decane quaternary ammonium） was synthesized by self-assembly reaction of AOD-I, Pb（NO3）2 and NaI, and structurally d...A new iodiplumbate polymer [（AOD）（Pb216）]n 1 （AOD = O-protonated 4-azonia-7- oxaspiro（4,5） decane quaternary ammonium） was synthesized by self-assembly reaction of AOD-I, Pb（NO3）2 and NaI, and structurally determined. Compound 1 crystallizes in the hexagonal system, space group P3, with a = 18.2704（8）, c = 8.1663（6） A, V= 2360.8（2） A3, Z = 3, De = 2.783 g/cm^3, F（000） = 1686, C8H17I6NOPb2, Mr = 1319.03, μ（MoKa） = 16.562 mm^-1, the final R = 0.0535 and wR = 0.1793 for 4943 observed reflections with I 〉 2σ（I）. In compound 1, three independent （PbEI6）^2-n infinite chains in each unit cell shape the sketch of compound 1 under the template of AOD-H^2＋ cation. Each （PbaI6）^2-n chain generates from the face-sharing of distorted PbI6 octahedra. （PbEI6）^2-n polyanions interact with AOD-H^2＋ cations by electrostatic interaction in the crystal to feature a so-called hybrid structure. Compound 1 was further characterized with IR, elemental analysis, fluorescence spectrum and thermal analysis. Based on the crystal structure data, DFT calculation was carried out to reveal the electronic structure of compound 1.展开更多
In this study,greatly enhanced Mn(Ⅱ) adsorption was achieved by as-synthesized diethylenetriaminepentaacetate acid intercalated Mg/Al layered double hydroxides (LDHs-DTPA).The adsorption capacity of LDHs-DTPA was 83....In this study,greatly enhanced Mn(Ⅱ) adsorption was achieved by as-synthesized diethylenetriaminepentaacetate acid intercalated Mg/Al layered double hydroxides (LDHs-DTPA).The adsorption capacity of LDHs-DTPA was 83.5 mg/g,which is much higher than that of LDHs-EDTA (44.4 mg/g),LDHs-Oxalate (21.6 mg/g) and LDHs (28.8 mg/g).The adsorption data of aqueous Mn(Ⅱ) using LDHs-DTPA could be well described by the pseudosecond order kinetics and Langrnuir isotherm model.Thermodynamics study results also showed that the adsorption process of Mn(Ⅱ) by LDHs-DTPA was exothermic as indicated by the negative △H value.Furthermore,based on the structural,morphological and thermostable features,as well as FT-IR and XPS characterizations of LDHs-DTPA and the pristine LDHs,the adsorption mechanism of Mn(Ⅱ) was proposed.The carboxyl groups of DTPA were proposed to be the main binding sites for Mn(Ⅱ),and the hydroxyl groups of LDHs also played a minor role in the adsorption process.Among the three common regeneration reagents,0.1 mol/L Na2CO3 was the best for reusing LDHs-DTPA in Mn(Ⅱ) adsorption.Besides,the Mn(Ⅱ) adsorption performance could be hindered in the presence of typical inorganic ions,especially cations.Further specific modifications of LDHs-DTPA are suggested to get more selective adsorption of Mn(ll) in practical applications.展开更多
基金supported by the Natural Science Foundation of Fujian Province (E0710008 and X0650070)the Innovation Fund for Young Scientist of Fujian Province (2007F3049)
文摘A new iodiplumbate polymer [（AOD）（Pb216）]n 1 （AOD = O-protonated 4-azonia-7- oxaspiro（4,5） decane quaternary ammonium） was synthesized by self-assembly reaction of AOD-I, Pb（NO3）2 and NaI, and structurally determined. Compound 1 crystallizes in the hexagonal system, space group P3, with a = 18.2704（8）, c = 8.1663（6） A, V= 2360.8（2） A3, Z = 3, De = 2.783 g/cm^3, F（000） = 1686, C8H17I6NOPb2, Mr = 1319.03, μ（MoKa） = 16.562 mm^-1, the final R = 0.0535 and wR = 0.1793 for 4943 observed reflections with I 〉 2σ（I）. In compound 1, three independent （PbEI6）^2-n infinite chains in each unit cell shape the sketch of compound 1 under the template of AOD-H^2＋ cation. Each （PbaI6）^2-n chain generates from the face-sharing of distorted PbI6 octahedra. （PbEI6）^2-n polyanions interact with AOD-H^2＋ cations by electrostatic interaction in the crystal to feature a so-called hybrid structure. Compound 1 was further characterized with IR, elemental analysis, fluorescence spectrum and thermal analysis. Based on the crystal structure data, DFT calculation was carried out to reveal the electronic structure of compound 1.
基金supported by the National Natural Science Foundation of China(Nos.21677055 and 21407052)the Key Project in the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(No.2015BAB01B04)the Fundamental Research Funds for the Central Universities,HUST(Nos.2017KFXKJC004 and 2016YXMS287)
文摘In this study,greatly enhanced Mn(Ⅱ) adsorption was achieved by as-synthesized diethylenetriaminepentaacetate acid intercalated Mg/Al layered double hydroxides (LDHs-DTPA).The adsorption capacity of LDHs-DTPA was 83.5 mg/g,which is much higher than that of LDHs-EDTA (44.4 mg/g),LDHs-Oxalate (21.6 mg/g) and LDHs (28.8 mg/g).The adsorption data of aqueous Mn(Ⅱ) using LDHs-DTPA could be well described by the pseudosecond order kinetics and Langrnuir isotherm model.Thermodynamics study results also showed that the adsorption process of Mn(Ⅱ) by LDHs-DTPA was exothermic as indicated by the negative △H value.Furthermore,based on the structural,morphological and thermostable features,as well as FT-IR and XPS characterizations of LDHs-DTPA and the pristine LDHs,the adsorption mechanism of Mn(Ⅱ) was proposed.The carboxyl groups of DTPA were proposed to be the main binding sites for Mn(Ⅱ),and the hydroxyl groups of LDHs also played a minor role in the adsorption process.Among the three common regeneration reagents,0.1 mol/L Na2CO3 was the best for reusing LDHs-DTPA in Mn(Ⅱ) adsorption.Besides,the Mn(Ⅱ) adsorption performance could be hindered in the presence of typical inorganic ions,especially cations.Further specific modifications of LDHs-DTPA are suggested to get more selective adsorption of Mn(ll) in practical applications.
