碳糊电极上无机膜固载血红蛋白的直接电化学

报道了用硅溶胶-凝胶(Sol-gel)膜将血红蛋白(Hb)固载于碳糊电极上的直接电化学行为.研究结果表明,Hb-Sol-gel修饰的碳糊电极在pH=7.0的缓冲溶液中于-0.275V(vs.Ag/AgCl)处有一对可逆的循环伏安氧化-还原峰,为Hb血红素辅基Fe(Ⅲ)/Fe(Ⅱ)电对的特征峰.HbFe(Ⅲ)/Fe(Ⅱ)电对的式量电位在pH5.0～11.0范围内与溶液pH值呈线性关系,表明Hb的电化学还原很可能是一个质子伴随着一个电子的电极过程.FTIR光谱证实,Sol-gel膜对Hb的固载没有破坏其天然结构.Hb-Sol-gel修饰的碳糊电极能够催化还原H₂O₂,可望将其用于制作第三代生物传感器.     

纳米氧化亚铜固载亚甲兰复合膜修饰玻碳电极的电化学性质及其对多巴胺的电催化

用十六烷基三甲基溴化铵为软模板制备了纳米氧化亚铜晶须,利用XRD和TEM进行表征。研究了纳米Cu2O-Nafion膜修饰玻碳电极的电化学性质,结果表明,纳米氧化亚铜在电极上表现出一对较为可逆的氧化还原峰,对应于Cu(Ⅱ)/Cu(Ⅰ)的氧化还原,峰电流与扫速成正比,表明纳米氧化亚铜在电极表面的电化学受表面控制。研究发现在亚甲基兰为媒介的情况下电极对多巴胺的催化能力进一步提高。在此电极上多巴胺呈现一对响应良好的准可逆氧化还原峰,峰电位差106 mV,峰电流大大提高,氧化峰电位大大降低,表现出良好的电催化作用。该电极可以在抗坏血酸存在下测定多巴胺。     

血红蛋白在离子液体[BMIM]PF6碳糊电极上的直接电化学

制备了离子液体[BMIM]PF6修饰碳糊电极(CILE), 并对其形貌和电化学行为进行了表征. 采用涂布法利用壳聚糖-皂土有机-无机复合膜将血红蛋白(Hb)固定于CILE电极表面, 利用紫外可见光谱、红外光谱和电化学方法等手段对包埋于膜内的Hb的性质进行了表征. 结果表明, Hb在薄膜内保持了其原始构象与生物活性, 循环伏安实验表明, 在pH=7.0的Britton-Robinson (B-R)缓冲液中, Hb表现出一对峰形良好的准可逆氧化还原峰, 为Hb Fe(III)/Fe(II)电对的特征峰, 对其直接电化学行为进行了研究, 求出式电位为-0.352 V(vs SCE), 电子转移数为0.885, 电荷传递系数为0.578, 表观异相电子转移速率常数为0.149 s-1.     

溶剂及电解质盐对氧在有机电解液体系中电化学还原的影响

应用线性循环伏安(CV)法研究了氧在几种有机电解液体系中的电化学还原过程.实验表明,氧在四丁基六氟磷酸铵(TBAPF6)/乙腈(MeCN)或TBAPF6/丙烯碳酸酯(PC)电解液中,均首先发生1电子还原生成O2-的过程,但电位回扫还原过程的可逆性却表现出很大差异:在乙腈溶液中反应可逆性较好,CV曲线表现出一对可逆的氧化还原峰,而在丙烯碳酸酯为溶剂的电解液中,氧还原过程可逆性差,不仅初始氧还原电流显著减小,而且表征O2-氧化的电流峰几乎消失.此外,电解质盐对氧还原过程也具有很大影响,在六氟磷酸锂(LiPF6)/乙腈电解液中,氧的还原可逆性较差.     

离子液体中电生成CoL催化行为研究

在离子液体中,研究了CoL(钴希夫碱配合物)的电化学行为,并进一步探讨了其对氯苄还原以及PhCH_2Cl与CO_2反应的催化特性.CoL在离子液体中呈现一对由扩散控制的单电子可逆氧化还原峰,通过电化学行为研究发现,其氧化还原峰电位不易随金属有机配合物的配体和离子液体阴离子的变化而变化,并求得了相应的扩散系数.同时,循环伏安图表明该体系能对PhCH_2Cl的还原起催化作用,反应经历一个ECE过程,另外,该体系还能催化PhCH_2Cl与CO_2反应,通过恒电位电解得到(PhCH_2)_2CO,说明常温常压下,CO_2可以通过CoL催化在离子液体中进行固定,得到新的有机化合物。     

肌红蛋白-纳米氧化铝模板-金胶复合组装体的电化学行为研究

基于自组装技术在玻碳电极表面构筑了肌红蛋白-纳米氧化铝模板-金胶复合组装体,研究了该纳米复合组装体的电化学性质。循环伏安和电化学交流阻抗实验结果表明,该纳米组装体结构致密稳定,固定在组装体中的肌红蛋白在0.2 mol/L醋酸-醋酸钠缓冲液中于-0.21 V(vs.Ag/AgC l)附近有一对准可逆的氧化还原峰,为肌红蛋白血红素辅基Fe(Ⅲ)/Fe(Ⅱ)的特征峰。带负电荷的金纳米粒子能为蛋白质分子提供具有生物兼容性的微环境,从而有利于其电子传递反应的发生。     

血红蛋白在亲水石墨烯-羟基磷灰石复合膜内的直接电化学及其电催化性能研究

将片层氧化石墨与聚苯乙烯磺酸钠反应,并于水热条件下水合肼还原快速合成亲水石墨烯片。透射电子显微镜分析显示,制得的聚苯乙烯磺酸钠改性的透明石墨烯类似波纹状的细纱。将血红蛋白(Hb)固定于羟基磷灰石和亲水石墨烯复合膜修饰电极上,研究了血红蛋白的直接电化学性质,构建了安培过氧化氢传感器。在该复合膜修饰电极上,血红蛋白表现出一对较好的氧化还原峰,其式量电位为-0.295 V,对应于Hb中FeⅢ/FeⅡ电对的氧化还原电位,且对过氧化氢的还原具有较好地催化作用,可作为传感器用于过氧化氢的检测。该生物传感器对过氧化氢的还原具有快速的安培响应(<5 s)和较低的检出限(0.58μmol/L)。     

蒽醌/聚吡咯复合膜修饰电极的电化学行为和电催化活性

在水溶液中制备了掺杂蒽醌磺酸盐(AQS)的聚吡咯(PPy)/玻碳复合膜修饰电极,采用循环伏安法和旋转圆盘电极技术研究了该修饰电极在不同pH值溶液中的电化学行为以及在pH=5.5的磷酸盐缓冲溶液中对氧还原反应的电催化性能和动力学.结果表明,与裸玻碳电极相比,PPy膜的存在不仅降低了AQS的反应电位和峰电位差,而且增大了其氧化还原反应的峰电流,H2AQ/HAQ-氧化还原对的电离常数为9.5.AQS/PPy膜修饰电极上氧的还原主要是两电子还原为H2O2的不可逆过程,H2AQ对氧还原反应起主要催化作用,还原过程符合异相氧化还原催化机理.该修饰电极具有良好的电化学重现性.     

血红蛋白在裸银电极上的直接电化学及其分析应用

报道了血红蛋白(Hb)在裸银电极上的电化学氧化还原行为。在+0.4～-0.2V(vs.SCE)电位范围内于pH=4.5的0.1mol/LNaAc-HAc底液中,血红蛋白产生一对灵敏的氧化还原峰。峰电位之差△E为0.25V(扫描速度20mV/s).动力学研究表明:电极反应的电子转移数n为0.94,表现电子传递速率常数Ks为0.032.连续电位扫描30min,峰电流变化分别为0.2μA(还原峰)和0.15μA(氧化峰).两峰与血红蛋白浓度在2×10^-7～2×10^-6mol/L和2×10^-6～1.5×10^-5mol/L范围内均呈良好线性关系,已应用于血红蛋白的分析测定。     

血红蛋白在碳纳米管修饰碳糊电极上的直接电化学行为

利用吸附法将血红蛋白(Hb)固定在碳纳米管修饰碳糊电极表面,制成稳定的固载Hb碳纳米管修饰电极,研究了Hb在碳纳米管修饰电极上的直接电化学行为.固载Hb的碳纳米管修饰电极在pH=7.0的PBS（磷酸盐缓冲溶液）中有一对相当可逆的循环伏安氧化还原峰,为Hb血红素辅基Fe(Ⅲ)/Fe(Ⅱ)电对的特征峰.式电位为－0.160 V(vs SCE),随扫描速度变化很小.电子转移数为1.021,近似为一个辅基发生电子转移.Hb在碳纳米管修饰电极表面的电子转移常数为0.0816 s－1,远大于亚甲蓝作媒介体时Hb的电子转移反应速率常数.应用于过氧化氢、三氯乙酸和硝基苯等的电催化还原,固定在碳纳米管修饰碳糊电极的血红蛋白表现出稳定且较高的催化活性.     

A STUDY OF THE REDOX CHARACTERISTICS OF THE TERNARY CLATHRATE COMPOUND Mo[S2CN(C2H5)2]4}+{FeCl4}-C6H5CH2SSCH2C6H5

The redox characteristics of the ternary clathrate compound {Mo[S₂CN(C₂H₅)₂]₄}⁺{C₆H₅CH₂SSCH₂C₆H₅}^-was studied by electrochemical measurement and quantum-chemical calculations.The cyclic voltammogram of this ternary clathrate compound in 0.1M KClO₄-DMF with a platinum electride had 2.pairs of redox peak.Both the electrochemical parameters derived from the voltammogram and the results of EHMO calculations indicate that the pair of redox peak at relatively positive potentials corresponds to the redox reaction of Fe(Ⅲ)/Fe(Ⅱ) which is irreversible in nature,while the pair of redox peak at more negative potentials corresponds to the redox reaction of Mo(Ⅴ)/ Mo(Ⅱ) which is semi-reversible.The calculations from experiment measurements are fairly agreement with the theoretical calculations.     

Dinuclear molybdenum complexes derived from diphenols: electrochemical interactions and reduced species

The new diphenolato complexes [{Mo(NO){HB(dmpz)₃}Cl}₂Q] where dmpz = 3,5-dimethylpyrazolyl and Q = OC₆H₄(C₆H₄O (n = 1 or 2), OC₆H₄CR=CRC₆H₄O (R = H or Et), and OC₆H₄CH=CHC₆H₄CH=CHC₆H₄O have been prepared and their electrochemical properties (cyclic and differential pulse voltammetry) compared with previously reported analogues where Q = OC₆H₄O, OC₆H₄EC₆H₄O (E = SO₂, CO and S), OC₆H₄ (CO)C₆H₄ C₆H₄(CO)C₆H₄O and 1,5- and 2,7-O₂C₁₀H₆. The electrochemical interaction between the redox centres in the new complexes is very weak, in contrast to that in the 1,4-benzenediolato and naphthalendiolato species. The EPR spectra of the reduced mixed-valence species [{Mo(NO){HB(dmpz)₃}Cl}₂Q]⁻ where Q = 1,3- and 1,4-OC₆H₄O and OC₆H₄SC₆H₄O shows that they are valence-trapped at room temperature, whereas those of the dianions [{Mo(NO){HB(dmpz)₃}Cl}₂Q]²⁻ where Q = 1,4-OC₆H₄O, OC₆H₄EC₆H₄O (E = CO or S) and OC₆H₄CH=CHC₆H₄CH=CHC₆H₄O shows that the unpaired spins on each molybdenum centre are strongly correlated (J, the spin exchange integral A_Mo, the metal-hyperfine coupling constant). The electrochemical properties and the comproportionation constants for the reaction [{Mo(NO){HB(dmpz)₃} Cl}₂Q] + [{Mo(NO){HB(dmpz)₃}Cl}O]₂]²⁻2[{Mo(NO) {HB(dmpz)₃}Cl}₂Q]⁻ where Q = diphenolato bridge, are compared with related compounds containing benzenediamido and dianilido bridges.     

双钼配合物氧化还原特性的研究

以MoCl₅和二乙胺基硫代甲酸钠为原料,在AlCl₃存在下于甲醇溶液中反应,生成双钼配合物Mo[S₂CN(C₂H₅)₂]⁺[MoCl₆]用循环伏安法研究了氧化还原特性。     

新型桥联双四面体簇合物的合成与表征

利用(μ₃-CCO₂Et)Co₃(CO)₉与单阴离子试剂[Mo(CO)₃(η⁵-C₅H₄R)]-[R=H,C(O)Me]的反应合成了2个新的含CCo₂Mo骨架的簇合物(μ₃-CCO₂Et)Co₂Mo(CO)₈(η⁵-C₅H₄R)[R=H(1);R=C(O)Me(2)],进而用其与双阴离子试剂{-M(CO)₃[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,W]反应合成了4个双四面体簇合物{(μ₃-CCO₂Et)CoMoM(CO)₇(η⁵-C₅H₄R)[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,R=H(3);M=Mo,R=C(O)Me(4);M=W,R=H(5);M=W,R=C(O)Me(6)].这6个化合物的C和H元素分析,IR,¹HNMR等表征都与其结构一致.晶体X射线衍射分析表明,化合物2属单斜晶系,C₂/c空间群,晶胞参数a=1.1264(3)nm,b=1.1879(3)nm,c=3.3565(10)nm,β=93.320(5)°,V=4.484(2)nm₃,Z=8,D_c=1.867g·cm^-3,F(000)=2480,R=0.0369,wR=0.1150.     

The Synthesis, Crystal and Molecular Structure of Tetrakis Dithiocarbamato Molybdenum(Ⅴ)Hexacloromolybdate

The title compound {Mo[S2CN( C2H5)2]4 1{MoCl6}-1 was synthesized,and its crystal structure was determined by X-ray diffraction.It is nionoclinic,space group P21/a with a=14.761(6)A b=16.012(6)A,c=17.108(9)A,β=102.63(4) and Z=4.The coordinates of a molybdenum atom were deduced from the Patterson function,and parameters of other atoms were found from successive Fourier syntheses.The block-diagonal least-siuares refinement for all alons gave final residual factors R=0.0908,Rw=0.0761.     

镧系离子(Nd3+、Ho3+、Er3+)与PMHFP和DAM三元配合物的制备及超灵敏跃迁的研究

镧系离子(Ln³⁺)同二安替吡啉甲烷(DAM)和1-苯基-3-甲基-4-苯甲酰基吡唑酮-5等β-二酮形成的三元配合物的超灵敏跃迁现象已有研究^[1-3]。Ln³⁺同1-苯基-3-甲基-4-七氟丁酰基吡唑酮-5(PMHFP)的二元配合物已经合成^[4]。本文研究Ln³⁺)-PMHFP-DAM体系中的超灵敏跃迁现象及其三元配合物的组成、结构和性质。     

Temperature-controlled Hydrothermal Synthesis of Copper(I or II) Coordination Polymers via a Variety of Copper Coordination Modes

Two 1D coordination polymers Cu₂^I(C₆N₃H₄)₂(1) and Cu^II(C₆N₃H₄)₂·H₂O(2) based on benzotriazole(Bta) were hydrothermally synthesized by controlling the crystallization temperature. Single-crystal X-ray diffraction (XRD) analyses reveal that compound 1 is a 1D tubular structure constructed from two types of 1D chains {-Cu-N=N-N-}_n, where the Cu(I) ions adopt linear, triangular, and tetrahedral coordination modes to connect two types of Bta ligands via π-π interaction inside the tubular-like chain. For compound 2, the Cu(II) ions assume a quadrilateral coordination mode linking to the Bta ligands to give 1D straight chains, which stacks through π-π interactions to construct a 2D layer structure. Further characterizations including elemental analyses, infrared IR spectra, thermogravimetric(TG) analyses and luminescence properties have been done.     

新型双四面体过渡金属簇合物的合成与表征

利用Co₂(CO)₈与[Cl₃CC(O)OCH₂]₂的反应合成了以C(O)OCH₂CH₂OC(O)桥联两个Co₃C四面体骨架为特征的新型双四面体簇合物[(CO)₉Co₃(μ₃-C)C(O)OCH₂]₂(1);1与不同物质的量比的Na[M(CO)₃C₅H₄R](M=Mo,W;R=H,C(O)Me)反应,得到一步交换的产物(CO)₉Co₃(μ₃-C)C(O)OCH₂CH₂OC(O)(μ₃-C)Co₂M(CO)₈(C₅H₄R)[M=Mo,R=H(2);M=Mo,R=C(O)Me(3);M=W,R=H(4);M=W,R=C(O)Me(5)]或两步交换的产物[(C₅H₄R)(CO)₈Co₂M(μ₃-C)C(O)OCH₂]₂[M=Mo,R=H(6);M=Mo,R=C(O)Me(7);M=W,R=H(8);M=W,R=C(O)Me(9)].5或9分别与Na[Mo(CO)₃C₅H₅]以12的物质的量比反应得到含一个手性四面体骨架(CoMoWC)的(C₅H₅)(CO)₈Co₂Mo(μ₃-C)C(O)OCH₂CH₂O·C(O)(μ₃-C)CoMoW(CO)₇(C₅H₄C(O)Me)(C₅H₅)(10)或含两个手性四面体骨架(CoMoWC)的[(C₅H₅)(C₅H₄C(O)Me)(CO)₇CoMoW(μ₃-C)C(O)OCH₂]₂(11);对化合物1_11进行了CH元素分析、IR和¹HNMR等表征.结果表明,在金属交换反应中处于不同簇环境下的Co(CO)₃基团反应活性不同.对化合物1进行了晶体X射线衍射分析.化合物1的晶体属单斜晶系,P2₁/n(#14)空间群,晶胞参数a=0.933 0(2)nm,b=1.519 7(4)nm,c=1.178 3(4)nm,=91.16(2)°,Z=2,F(000)=972.分子结构呈中心对称.     

Synthesis of metallocenes of zirconium, hafnium, manganese, iron, tin, lead and half-sandwich complexes of rhodium and iridium containing the ligands (η-C5R4CR′2PMe2), where R and R′ may be H or Me

The dimethylphosphino substituted cyclopentadienyl precursor compounds [M(C₅Me₄CH₂PMe₂)], where M=Li⁺ (1), Na⁺ (2), or K⁺ (3), and [Li(C₅H₄CR′₂PMe₂)], where R′₂=Me₂ (4), or (CH₂)₅ (5), [HC₅Me₄CH₂PMe₂H]X, where X⁻=Cl⁻ (6) or PF₆⁻ (7) and [HC₅Me₄CH₂PMe₂] (8), are described. They have been used to prepare new metallocene compounds, of which representative examples are [Fe(η-C₅R₄CR′₂PMe₂)₂], where R=Me, R′=H (9); R=H and R′₂=Me₂ (10), or (CH₂)₅ (11), [Fe(η-C₅H₄CMe₂PMe₃)₂]I₂ (12), [Fe{η-C₅Me₄CH₂P(O)Me₂}₂] (13), [Zr(η-C₅R₄CR′₂PMe₂)₂Cl₂], where R=H, R′=Me (14), or R=Me, R′=H (15), [Hf(η-C₅H₄CMe₂PMe₂)₂]Cl₂] (16), [Zr(η-C₅H₄CMe₂PMe₂)₂Me₂] (17), {[Zr(η-C₅Me₄CH₂PMe₂)₂]Cl}{(C₆F₅)₃BClB(C₆F₅)₃} (18), [Zr{(η-C₅Me₄CH₂PMe₂)₂Cl₂}PtI₂] (19), [Mn(η-C₅Me₄CH₂PMe₂)₂] (20), [Mn{(η-C₅Me₄CH₂PMe₂B(C₆F₅)₃}₂] (21), [Pb(η-C₅H₄CMe₂PMe₂)₂] (23), [Sn(η-C₅H₄CMe₂PMe₂)₂] (24), [Pb{η-C₅H₄CMe₂PMe₂B(C₆F₅)₃}₂] (25), [Pb(η-C₅H₄CMe₂PMe₂)₂PtI₂] (26), [Rh(η-C₅Me₄CH₂PMe₂)(C₂H₄)] 29, [M(η,κP-C₅Me₄CH₂PMe₂)I₂], where M=Rh (30), or Ir, (31).     

Reactions of Lewis bases with tetrakisdiphenylamide uranium(IV)

The coordinatively unsaturated uranium(IV) complex U[N(C₆H₅)₂]₄ has been prepared via the stoichiometric reaction of diphenylamine with [(Me₃Si)₂N]₂ H₂. U[N(C₆H₅)₂]₄ coordinates Lewis bases such as Et₂O, THF, pyridine or (EtO)₃PO, based on electronic absorption spectroscopy and ¹H NMR studies. Exchange between U[N(C₆H₅)₂]₄ and U[N(C₆H₅)₂]₄(L), where L is THF or pyridine, is rapid on the NMR time-scale between 307 and 323 K. Measurement of equilibrium constants for L = THF provides ΔH and ΔS values of −60 kJ mol⁻¹ and −1.8 × 10² J K⁻¹ mol⁻¹, respectively. U[N(C₆H₅)₂]₄ coordinates and binds (EtO)₃PO much more tightly (K_eq = & > 10⁴ M⁻¹) than THF or pyridine with the exchange rate between U[N(C₆H₅)₂]₄ and U[N(C₆H₅)₂]₄[OP(OEt)₃] being close to the NMR time-scale.