有机-无机型杂多酸相转移催化氧化脱硫性能研究

合成了四种有机-无机型杂多酸催化剂,包括[π-C₅H₅NC₁₆H₃₃]₃[PW₄O₁₆],[π-C₅H₅NC₁₆H₃₃]₃[PMo₄O₁₆],[π-C₅H₅NC₁₂H₂₅]₃[PW₄O₁₆]和[π-C₅H₅NC₁₂H₂₅]₃[PMo₄O₁₆]. 以有机硫的正辛烷溶液为模拟油品,H₂O₂为氧化剂,乙腈为萃取剂,在两相体系中,考察了上述四种催化剂对模拟油品中二苯并噻吩(DBT)氧化脱硫的催化活性. 结果表明,[π-C₅H₅NC₁₆H₃₃]₃[PW₄O₁₆]具有最佳的催化活性. 采用[π-C₅H₅NC₁₆H₃₃]₃[PW₄O₁₆]进行后续研究发现,反应完毕,[π-C₅H₅NC₁₆H₃₃]₃[PW₄O₁₆]以沉淀的形式析出,可以重复利用且脱硫效果很好. 研究表明,上述有机-无机型杂多酸属于相转移催化剂,氧化脱硫反应体系属于反应控制相转移催化体系. 在相同实验条件下,由于电子云密度和空间位阻效应共同的作用,DBT、噻吩(TH)、苯并噻吩(BT)和4,6-二甲基二苯并噻吩(4,6-DMDBT)脱硫由易到难的顺序为DBT >4,6-DMDBT >BT >TH,并分别通过GC-MS分析确定它们的氧化产物. 将[π-C₅H₅NC₁₆H₃₃]₃[PW₄O₁₆]进一步应用于柴油氧化脱硫,其中硫含量由355 mg/kg (mg/kg等同于ppmw)降至26 mg/kg,去除率达92.7%. 利用上述四种有机-无机型杂多酸作催化剂,研究DBT氧化反应过程动力学,确定DBT的表观反应级数均为一级,表观活化能为47.9～55.4 kJ/mol.     

Fabrication of nanoreactors based on polyoxoperoxometalates and enhancement of their catalytic activity

The nanoreactors were fabricated by reacting amphiphilic quaternary ammoniums and polyoxoperoxometalates K_n[PW_12-xTi_x- O_40-x（O₂）_x]（x=1,2 and 3;n = 5,7 and 9）(K₅[PW₁₁TiO₃₉（O₂）],K₇[PW₁₀Ti₂O₃₈（O₂）₂]and K₉[PW₉Ti₃O₃₇（O₂）₃]).Fourier transform infrared spectroscopy（FT-IR）,transmission electron microscopy（TEM） were used to characterize the resulting samples. This kind of nanocatalysts could promote NH₄SCN’ degradation into simple inorganic compounds such as SO₄^2-,HCO₃^- and NO₃^- only using oxygen as an oxidant under room conditions.     

两种多酸型酪氨酸酶抑制剂的性能研究

以H₃PW₁₂O₄₀和H₄SiW₁₂O₄₀(简写为PW₁₂和SiW₁₂)为效应物, 测定其对酪氨酸酶活力的抑制作用. 通过非变性聚丙烯凝胶(Native-PAGE)电泳确定酪氨酸酶是多家族基因编码, 其分子量为3×10⁴~3.4×10⁴, 4.2×10⁴~4.6×10⁴, 6.4×10⁴~6.8×10⁴, 且均具有活性, 测定PW₁₂和SiW₁₂对酪氨酸酶的抑制效果, 并结合酶动力学法研究其抑制机理. 结果表明, 当PW₁₂和SiW₁₂浓度分别达到13和25 mmol/L时, 酪氨酸酶的活力完全被抑制, 即PW₁₂和SiW₁₂对酪氨酸酶二酚酶具有不同程度的抑制效果. 当所加酶量为0.0173 mg/mL时, PW₁₂和SiW₁₂对酪氨酸酶二酚酶活力的半抑制率 (IC₅₀)分别为1.57和2.31 mmol/L, 它们对酪氨酸酶二酚酶的抑制均为可逆过程. 其中, PW₁₂对二酚酶的抑制类型为混合型, 其K_I及K_IS分别为0.34和0.43 mmol/L, SiW₁₂对二酚酶的抑制类型表现为竞争型, 其K_I为0.59 mmol/L. 综合考虑IC₅₀值和抑制常数等参数, PW₁₂对酪氨酸酶二酚酶的抑制能力优于SiW₁₂.     

Keggin型多酸基晶态材料的合成及催化性能

通过引入Keggin型多酸离子[PW₁₂O₄₀]^3-到Co-bbp(bbp:3,5-双(4-吡啶基)吡啶)体系中,在水热条件下合成一个新的物质Co{bbp}₂(H₂O)₄(HPW₁₂O₄₀)(1)。 通过X射线单晶衍射(CDD)分析表明该化合物为单斜晶系,C2空间群。 所呈现的结构由金属Co和有机配体bbp配合形成金属-有机单体,然后通过配体间的π…π键堆积成二维层状框架结构,多酸[PW₁₂O₄₀]^3-作为模板嵌入框架的空穴内,形成一个以多酸为模板超分子化合物。 通过研究化合物1的催化性质,结果发现其对罗丹明B(RhB)具有很好的催化降解能力(可见光照120 min后降解率为94%),并且可以电催化亚硝酸根(NO₂^-)和抗坏血酸(AA),是一个具有多功能的催化剂。     

PEO-12-钨磷酸质子导电聚合物电解质膜

以聚氧乙烯(PEO)为基质, 在其中掺杂适量的钨磷酸, 制备PEO-H₃PW₁₂O₄₀质子导电聚合物电解质膜. XRD及IR测试表明体系中Keggin阴离子与PEO链相互作用形成新的化合物; Keggin阴离子的存在有利于水合质子的形成. PEO-H₃PW₁₂O₄₀复合膜的电导率室温最高可达4.0×10^－3 S•cm^－1.     

(Fe,Cr)3O4催化剂表面酸性的研究

本文研究了(Fe,Cr)₃O₄催化剂的表面酸性,发现其表面结构具有可变性,表面主要存在Fe²⁺(α位)和Fe³⁺(β位)两种酸中心,β位上吸附吡啶的E_d=278.8±13.8kJ/mol。     

一种基于2,6-双(1,2,4-三唑-1-基)吡啶的新型多酸基无机-有机杂化材料的合成、结构与质子导电性能研究

采用水热法合成了一种新型多酸基无机-有机杂化材料{[Co(btp)(Hbtp)(H₂O)₃](PW₁₂O₄₀)·3H₂O}_n(1),并对化合物1进行了结构测定。X射线单晶衍射结果显示，Co(Ⅱ)离子通过btp配体连接形成一维链，[PW₁₂O₄₀]^3-游离于相邻一维链相互交叉形成的孔隙中，从而扩展成三维结构。热重分析表明化合物1具有良好的热稳定性。此外，还对化合物1的质子导电性能进行了研究。结果表明，化合物1在358 K和98%RH条件下的质子电导率为6×10^-5 S·cm^-1。     

Keggin 型磷钨酸盐修饰碳糊电极传感多巴胺的研究

多金属氧酸盐作为一类阴离子簇合物,由于其结构的多样性和尺寸大小的可调变性,在电化学、催化和药学等领域引起了人们的广泛关注.本文制备了多酸Co(C₁₅N₆H₁₂)₂[PW₁₂O₃₈]·5H₂O（Co[PW₁₂O₃₈]）修饰碳糊电极并通过电化学阻抗谱、循环伏安法以及差分脉冲伏安法对多巴胺的传感性能进行了研究.对其制备条件和检测条件分别进行了优化.在优化条件下,制备的传感器对多巴胺具有良好的选择性和灵敏度的检测能力.多巴胺的线性响应范围为8.0x10^-6 mol·L^-1至3x10^-5 mol·L^-1,灵敏度为0.039 μA·(μmol·L^-1)^-1,检出限（S/N=3）为5.4 x10^-6 mol·L^-1. 制备的多酸修饰碳糊电极用于检测多巴胺表现出良好的稳定性和重现性,并且对抗坏血酸、尿酸等常见的干扰物质,具有良好的抗干扰性. 多酸修饰的碳糊电极制备过程简单方便,成本低,传感性能良好,对应用于电化学传感器检测多巴胺具备潜在的应用前景.      

Zn(NO3)2-Leu-H2O体系(25℃)的相平衡及新相配合物的合成与性质

用半微量相平衡方法研究了硝酸锌-亮氨酸-水体系在25℃及全浓度范围内的溶度性质,绘制了体系的相图和饱和溶液折光率曲线,发现并制备了未见报道的非一致溶解配合物[Zn(Leu)(NO3)2(H20)]·H20(A)和Zn(Leu)2(NO3)2·H20(B),通过化学分析、元素分析、IR和TG-DTG等对其组成、结构及热稳定性进行了研究.用精密转动弹热量计测定配合物的标准燃烧能分别为(-12692.80±5.83)和(-15345.71±9.11)J/g,求得它们的标准燃烧焓分别为(-4523.22±2.08)和(-7208.86±4.28)kJ/mol,标准生成焓分别为(-615.67±2.27)和(-1863.16±4.60)kJ/mol     

镧系元素Dawson结构钨钒磷四元杂多配合物的合成、表征以及对H2O2分解的催化活性

合成了通式为K₁₅H₃[Ce(P₂W₁₆VO₆₁)₂]·61H₂O、K₁₅H₄[Ln(P₂W₁₆VO₆₁)₂]·xH₂O(Ln=La³⁺,Pr³⁺,Nd³⁺,Sm³⁺,Eu³⁺,Gd³⁺,Dy³⁺,Yb³⁺)的9种镧系元素Dawson结构的钨钒磷四元杂多配合物,并用IR、UV、NMR、ESR、XRD、TG-DTA等对其结构和性质进行了研究。该类配合物具有与K₁₆[Ce(P₂W₁₇VO₆₁)₂]·50H₂O类似的结构,对H₂O₂分解有较高的催化活性。     

Ionothermal Synthesis and Characterization of Two Polyoxometalate-based Supramolecules

Two novel 3D supramolecular architectures with hexamolybdate and phosphotungstate anions were synthesized under ionothermal conditions. The structures were named as[Cu^I(L1)₂]₂L2[Mo₆O₁₉](1) and[Cu^I(L3)₂]_2.5· H_0.5[PW₁₂O₄₀]·H₂O(2)(L1=2,2'-bipyridine, L2=4,4'-bipyridine, L3=2,2'-biimidazole) and characterized via Fourier transform infrared spectroscopy(FTIR) and FT-Raman spectroscopy analyses. Single-crystal X-ray diffraction analysis revealed that the two compounds crystallized in the space group P and were constructed through hydrogen bonding.     

Four Coordination Polymers Assembled with a New Biscarboxyl-functionalized Schiff Base Ligand

Based on a new biscarboxyl-functionalized Schiff base ligand 1,2-cyclohexanediamino-N,N'-bis[3-methoxyl-5-(p-carboxyl-phenylazo)] salicylidene(H₄L), four polymers,[(CH₃)₂NH₂]₂·[Mn₃(L)₂(H₂O)₄]·2DMF(CP1),[Fe₂(L)(H₂O)(DMF)](CP2),[(CH₃)₂NH₂]·[Cu(HL)]·H₂O(CP3) and[Ni₂(L)(teta)]·2DMF·H₂O(CP4), have been synthesized(teta=5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). In CP1, both of the internal[N₂O₂] pocket and the external carboxylate groups of L^4- anion are ligated by Mn²⁺ ions, and the structure displays a layer. In CP2, the Fe²⁺ cations are linked by L^4- anions to form a binuclear double chain. CP3 displays a[Cu₂(HL)₂] dimer. In CP4, the Ni²⁺ ions are connected by L^4- anions to form a chain. The structures are further linked by hydrogen bonds to form 2D or 3D supramolecular architectures, respectively. CP1 exhibits adsorption ability to three organic dyes.     

室温固相反应制备Keggin结构杂多酸铵盐纳米粒子

纳米材料由于其量子尺寸效应及表面效应而在磁、光、电等方面显示出许多常规粒子所不具有的特性[1] .纳米材料成功应用的实例及潜在应用前景推动了各种纳米粉末的合成及合成方法的发展 [2～ 4 ] .利用低温固相反应制备纳米粒子尚不多见 ,但已有报道 [5,6] .多金属氧酸盐因其独特的结构而具有较高的催化活性、导电性、磁性、光电致变色性以及抗病毒活性 ,因而有着广阔的应用前景 ,这些方面的研究已越来越引起人们的兴趣 [7～ 10 ] .本文采用室温固相反应首次制备了多金属氧酸盐纳米粒子 (NH4 ) 3PMo12 O4 0 · 9H2 O(1 )和 (NH4 ) 3PW12…     

磷钨酸插层MgAl水滑石层间距的调变及催化酯化脱酸性能

通过改变离子交换温度和时间合成了具有不同层间距的磷钨酸(H_3PW_(12)O_(40),HPW)插层MgAl水滑石(LDHs),采用XRD、FT-IR、Raman、~(31)P MAS NMR、ICP-AES和Hammett指示剂-正丁胺滴定法等表征其性质,并研究其对模型原油的催化酯化脱酸性能。高的离子交换温度有利于形成较大的层间距(d_(003)约1.46 nm),较长的交换时间有利于形成较小的层间距(d_(003)约1.05 nm)。不同的层间距源自HPW在层间不同的存在形式,P_2W_(18)O_(62)~(6-)以C_2轴倾斜于层板和PW_(11)O_(39)~(7-)以C_2轴垂直于层板的方式排列于层间时,形成d_(003)约1.46 nm的层间距;PW_(12)O_(40)~(3-)与层板发生嫁接,并以C_2轴垂直于层板的方向排列于层间时,形成d_(003)约1.05 nm的层间距。层间P_2W_(18)O_(62)~(6-)和PW_(11)O_(39)~(7-)能产生更高比例的中强酸中心,同时大的层间距有利于反应物扩散进入层间与酸中心接触,能够提高LDHs的催化酯化脱酸性能。     

Assembly of Three Scandium-containing Heteropolytungstates Based on a Building-block Synthetic Strategy

Three novel scandium-containing heteropolytungstates[Sc₃(H₂O)₃NO₃(PW₉O₃₄)₂]^10-(1a),[Sc₈(H₂O)₂(GeW₉O₃₄)₂(GeW₆O₂₆)₂]^12-(2a) and[Sc₁₁(W₆O₁₀)₂(OH)₂(H₂O)₁₆(BiW₉O₃₃)₆]^27-(3a) were synthesized by reactions of Sc^III ions with trilacunary Keggin precursors,[A-α-XW₉O₃₄]^n-(X=P, Ge, n=9, 10) or[B-α-BiW₉O₃₃]^9-, in NaOAc/HOAc buffer solution under conventional synthetic condition, respectively. All the three compounds were characterized by means of single-crystal X-ray diffraction(XRD), Fourier transform-infrared(FTIR) spectroscopy ultraviolet-visible(UV-Vis) spectroscopy, elemental analysis, and thermogravimetric analysis. The aqueous solution stability of the sandwich polyanion[Sc₃(H₂O)₃NO₃(PW₉O₃₄)₂]^10- was also verified by electrospray ionization mass spectrometry(ESI-MS) due to its good solubility in water.     

Synthesis of Highly Sensitive Fluorescent Probe Based on Tetrasubstituted Imidazole and Its Application for Selective Detection of Ag+ Ion in Aqueous Media

A small molecule fluorescent probe, 4-[2-(4-chlorophenyl)-4,5-diphenyl-1H-imidazol-1-yl]aniline(L) for detecting Ag⁺ ion was gently synthesized via one-pot multi-component reaction catalyzed by H₃[PW₁₂O₄₀] under solvent-free microwave irradiation. When the concentration of Ag⁺ ion changed from 0 to 8.0×10⁻⁶ mol/L in the solution of H₂O/CH₃OH(19:1, volume ratio), the fluorescence emission spectrum was blue-shifted and accompanied by a gradual increase in fluorescence intensity with a low detection limit of 3.0×10⁻¹¹ mol/L. Moreover, UV-Vis absorption titration experiment demonstrated a 1:1 stoichiometric ratio and an association constant of (9.95±0.44)×10⁵ L/mol between probe L and Ag⁺ ion, and thus their complexation mechanism was also proposed and verified. More importantly, this fluorescent probe was remarkably specific for Ag⁺ ion under the interference of other metal ions and exhibited a wide pH application range of 4.0-8.0. Additionally, preliminary application of this probe was also carried out and satisfactory results were shown.     

多酸掺杂Bi2O3-x/Bi光催化剂用于高效可见光催化降解四溴双酚A和NO去除

四溴双酚A(TBBPA)是一种重要的塑料添加剂和阻燃剂,广泛用于树脂、塑料、胶黏剂以及涂料中.它不仅是持久性的机污染物,还是一种内分泌干扰物,具有免疫毒性、神经毒性和细胞毒性.NOx,特别是NO,是主要的大气污染物之一,是形成PM2.5的重要前体,也容易引起酸雨,引发光化学烟雾、臭氧损耗、温室效应等,严重危害生态环境和...     

Two alkynyl functionalized Co(II)-MOFs as fluorescent sensors exhibiting selectivity and sensitivity for Fe3+ and nitroaromatic compounds

Two alkynyl functionalized 3D frameworks with different structures were successfully synthesized for selective and sensitive detection of Fe³⁺ ions and nitroaromatic compounds through fluorescence quenching.     

硝酸镧水合物和无水硝酸镧在水内及一水硝酸镧在醇内溶解热的测定

本文测定了六水、四水、一水和无水硝酸镧在水中的溶解热和一水硝酸镧在甲醇、乙醇和正丙醇中的溶解热,求得了各种水合硝酸镧和无水硝酸镧的标准生成热、晶格能和相应的标准脱水焓。