双水杨醛缩乙二胺烷基钴(Ⅲ)配合物电化学氧化动力学的研究

用循环伏安法、计时电流法、线性扫描伏安法及lgi～E法研究了双水杨醛缩乙二胺烷基钴(Ⅲ)配合物[RCo(Salen),R=CH₃,C₂H₅,n-C₄H₉,i-C₄H₉]在Au电极上的电化学氧化动力学过程,测定了RCo(Salen)的电极反应的速率常数k_s、电子转移数n₁、电荷传递系数a、标准电极电位E⁰、扩散系数D;同时,还测定了氧化产物化学分解加速率常数k_f及分解产物电解氧化的电子转移数n₂等参数,实验表明RCo(Salen)的电化学反应是ECE过程,R基对E⁰、k_f等均有影响。     

含茂基及双水杨醛缩乙二胺基稀土有机配合物的合成

由席夫碱双水杨醛缩乙二胺与三茂稀土在室温上反应,合成了６个和稀土有机配合物,并通过元素分析、ＩＲ和ＭＳ表征。     

辅酶B_(12)模型化合物的研究——Ⅰ.双水杨醛缩乙二亚胺烷基钴(Ⅲ)配合物Co-C键的性质

本工作合成、表征了一系列辅酶B_(12)模型化合物RCo(Salen)L,其中R=CH_3,C_2H_5,n和i-C_3H_7,n和i-C_4H_9,研究了上述配合物固体和溶液的Co-C键稳定性,结果表明:固体配合物Co-C键断裂的温度受烷基位阻影响,它们具有以下顺序:CH_3>C_2H_5>n-C_3H_7≈n-C_4H_9≈i-C_4H_9≈i-C_3H_7.此外还确定了影响配合物Co-C键在溶液中稳定性的因素.     

水杨醛缩氨基硫脲合锑(Ⅲ)、铋(Ⅲ)配合物的固相合成

水杨醛缩氨基硫脲与三碘化锑、三碘化铋通过固相反应，合成了新的配合物[SbI3(C8H9N3OS)]，[BiI3(C8H9N3OS)]。经元素分析、X-射线粉末衍射，中红外、远红外光谱和差热一热重分析，确定了其组成和结构。对XRD谱进行指标化，确定了配合物的晶系和晶胞参数。     

乙二胺双缩5-氯水杨醛Sclliff碱铜配合物的合成及晶体结构

合成了N,N′-二(5-氯水杨醛)缩乙二胺合铜配合物([Cu(5-ClSalen)]),用单晶X射线衍射法测定了晶体结构.其晶体属三斜晶系,空间群P-1,晶胞参数a=0.83285(1)nm,b=0.95170(4)nm,c=1.09304(4)nm,α=115.130(2)°,β=94.694(2)°,γ=101.127(2)°,V=0.75642(4)nm3,分子式C16H12Cl2CuN2O2,Mr=398.72,Z=2,Dc=1.751g/cm3.在配合物中,Cu处于两个氮原子和两个酚氧原子形成的平面四方场中.     

含水杨醛缩对硝基苯甲酰腙的钒酰配合物和钴配合物的合成和晶体结构

本文合成了含水杨醛缩对硝基苯甲酰腙(简写为H2L)的钒酰配合物VOL(CH3OH)(CH3O)(1,C16H16N3O7V,Mr=413.26)和钴配合物[CoL(C5H5N)3]NO3C5H5N(2,C34H29N8O7Co,Mr=720.58)。配合物1属单斜晶系,空间群为P21/c,a=7.3253(3),b=18.8237(9),c=12.9014(5)?b=91.672(1),V=1778.2(1)3,Z=4,F(000)=848,m(MoKa)=0.603mm1,R=0.0470,wR=0.1312。配合物2属单斜晶系,空间群为P21/c,a=11.4196(8),b=17.157(1),c=17.081(1)?b=96.8233(9),V=3323.0(4)3,Z=4,F(000)=1488,m(MoKa)=0.578mm1,R=0.0455,wR=0.1311。在配合物1中,钒(V)原子由周围的酰氧基原子、配体L2的3个配位原子,去质子化甲醇的甲氧基原子和配位甲醇的氧原子配位,形成畸变的VO(ONO)(O)(O)八面体配位构型。晶体内每2个分子间通过氢键作用缔合成中心对称的分子对,OH…N氢键键长为2.861(4)?键角163.20。晶体中存在着弱p-p共轭作用。在配合物2中,钴(Ⅲ)原子由1个L2的3个配位原子和3个配位吡啶分子的3个氮原子配位,呈N4O2八面体配位构型。     

水杨醛缩糠胺合钴（Ⅲ）配合物的合成,表征与晶体结构

合成了水杨醛缩糠胺合钴（Ⅲ）配合物Co（SF）3[HSF=水杨醛缩糠胺Schiff碱],通过IR和单晶X射线衍射测定了其结构.配合物属三斜晶系,空间群P墿,晶体学参数a=0.900 64（8）nm,b=1.061 13（9）nm,c=1.636 23（14）nm,α=93.989 0（10）°,β=94.886 0（10）°,γ=93.627 0（10）°.分子式C36H30CoN3O6,V=1.550 5（2）nm3,Z=2,Dc=1.413 g/cm3,F（000）=684,R1=0.0350,wR2=0.0958[I〉2sigma（I）],S=1.068.在配合物分子中,Co原子处于三个N原子、三个酚O原子形成的变形八面体场中.     

水杨醛缩氨基硫脲合钴(Ⅱ)的晶体结构及其荧光性质

在甲醇和DMF溶剂里,以Schiff碱水杨醛缩氨基硫脲(简写为HL)和六水二氯化钴合成了配合物[CoHL2].H2O.DMF.在配合物[CoHL2]中,钴(Ⅱ)原子具有扭曲的N2O2S2八面体配位构型,晶体通过分子间氢键作用形成二维的无限网状结构.红外光谱表明,配体在形成配合物后,νS=O,νC=O和νC=N红移.荧光光谱表明,配合物金属对配体n-π*激发引起的荧光发射峰有较大的影响.     

水杨醛二缩乙二胺锰(Ⅱ)配合物为载体的高选择性亚硫酸根离子电极的研究

研究了水杨醛二缩乙二胺锰(Ⅱ)配合物为载体的阴离子选择性电极。结果表明,水杨醛二缩乙二胺锰(Ⅱ)配合物对SO_3~(2-)有较高的选择性,且电极呈现反Hofmeister行为,其选择性次序为SO_3~(2-)>I~->SCN~->ClO_4~->NO_2~->NO_3~->S_2O_3~(2-)>Cl~->SO_4~(2-)。该电极响应速度快,具有良好的稳定性。用于化学试剂中SO_3~(2-)的测定,相对标准偏差为0.42％。     

Electrochemical Characterization of Myoglobin‐Polylysine Films at a Temperature Range of 6–80 °C

This work demonstrated for the first time that myoglobin cross‐linked in polylysine films is electrochemically active at 6 °C. At 6 °C, these protein films exhibited reversible reduction/oxidation peaks which are characteristic of Fe^III/Fe^II redox couple. The estimated current function densities (J=1.6×10^?4 C/V cm²), surface concentrations (Γ_T=0.10 nmol/cm²) and standard electron transfer constant (k_s=13.86 s^?1) at 6 °C for the data taken at a scan rate of 0.1 V/s were similar to those which were obtained at 10, 15 and 23 °C. Basically, this study shows a possible electrocatalytic application of these myoglobin/polylysine films, for example in low temperature sensing applications.     

手性Salen及Ga(Salen)催化苯基锂对环氧环己烷对映选择性开环反应

合成了14个含1,2-环己二胺、1,2-二苯基乙二胺或邻苯二胺的手性Salen化合物, 研究了手性Salen直接催化苯基锂对环氧环己烷的不对称开环反应, 结果表明二胺的结构和苯环上3,3'-位取代基对反应的对映选择性有很大的影响. 用Salen与 Me₃Ga原位生成的Ga(Salen)催化苯基锂对环氧环己烷的不对称开环反应, 与用Salen直接催化相比, 得到了更好的化学产率和对映选择性. 当用Ga(Slane) 15为催化剂时, 最佳ee值为73%.     

离子液体中Mn（Salen）催化仲醇的氧化反应研究

以PhI(OAc)2为氧化剂,考察了1,3-二烷基咪唑硫酸酯系列离子液体中Mn(Salen)催化仲醇氧化的反应. 结果表明, 在MMISM-CH2Cl2(1:4,v:v)混合溶剂中, 反应条件为n((-苯乙醇): n(醋酸碘苯): n(催化剂1c)=50: 70: 1时, (-苯乙醇的转化率可以达到97.8%, 产物苯乙酮的选择性为100%, 远高于在纯CH2Cl2中的结果, 也要好于[bmim]BF4和[bmim]PF6对该反应的促进作用. 此外, BMISM及BEISE对催化剂1c有较好的稳定作用,催化剂可以重复使用.     

Electrochemical Response of Cobalt(II) in the Presence of Ammonia

The electrochemical oxidation of cobalt(II) at gold, boron‐doped diamond, basal and edge plane pyrolytic graphite, and highly oriented pyrolytic graphite electrodes in aqueous solutions containing NH₃ has been studied using cyclic voltammetry, with subsequent chemical and electrochemical processes explained in detail. Furthermore, the electro‐reduction of [Co(NH₃)₆]³⁺ in the presence of different electrolytes has also been studied to obtain a better understanding of the oxidation pathway of the Co(II)‐ammine complexes. In aqueous solution the mechanism can be described by the following scheme:     

NHPI/Co(Salen)催化氧化取代甲苯

以分子氧为氧化剂,N-羟基邻苯二甲酰亚胺(NHPI)为引发剂,Co(Salen)配合物[NHPI/Co(Salen)]为催化剂,偶氮二异丁腈(AIBN)为助引发剂,AcOH为溶剂,催化氧化取代甲苯制备取代苯甲酸。最佳反应条件为:甲苯6mmol,q(NHPI)=10%,q[Co(Salen)]=0.5%,q(AIBN)=1%,O2(0.1MPa),AcOH10mL,于80℃反应20h,甲苯转化率92.7%,苯甲酸选择性88.9%。     

EPR Detection and Characterization of High-Valent Manganese Complexes in MnIII(Salen) Catalyzed Aerobic Olefin Epoxidation

Using EPR, high-valent Mn^IV complexes have been detected in Mukaiyama's catalytic system, Mn^III(Salen)/Isobutyraldehyde/O₂, and shown to form also in the model system Mn^III(Salen)/Peroxyisobutyric acid. Their possible role in alkene epoxidation is discussed.     

Comparative Study of Aerobic Alkene Epoxidations Catalyzed by Optically Active Manganese(iii) and Cobalt(ii) Salen Complexes

A comparative study of aerobic alkene epoxidations in the presence of pivalaldehyde catalyzed by the optically active Mn(III)Salen and Co(II)Salen complexes has been performed. The nature of the asymmetric induction is discussed.     

Electrochemical Characterization of a Pyrolytic Carbon Film Electrode and the Effect of Anodization

A pyrolytic carbon (PC) film electrode was fabricated by the chemical vapor deposition (CVD) method. This report deals with the preparation, characterization and electrochemical behavior of this carbon film. Cyclic voltammetry, linear sweep voltammetry, Raman spectroscopy and scanning electron microscopy were employed to characterize the electrode. Low background current and capacitance were observed and the rate of charge transfer for Fe(CN) redox couple was determined via cyclic voltammetry. Also the effect of the anodic activation on the electrochemical activity was evaluated and characterized with respect to the sequence of voltage applied to the electrode. The excellent electrochemical activity and low background current are the reasons why this electrode is attractive for electroanalysis measurements with lower detection limit.     

Spectroscopic and Electrochemical Characterization of Iron(II) and 2,4-Dinitrotoluene

The objective of this work was the development of reliable methods to determine 2,4-dinitrotoluene, a precursor to explosives. A complex between Fe(II) ion and 2,4-dinitrotoluene was formed in solution and characterized by ultraviolet-visible absorption spectroscopy using Job’s plots and attenuated total reflection-Fourier transform infrared spectroscopy. Surface modification of glassy carbon electrodes were performed with iron nanoparticles via electrochemical reduction of iron(II). The modified electrode was employed for the determination of 2,4-dinitrotoluene. Scanning electron micrographs showed that the iron nanoparticles were incorporated on the surface of glassy carbon electrode. The electrochemical determination of 2,4-dinitrotoluene was performed by cyclic voltammetry using the modified electrode. The iron modified electrode produced larger reduction currents than the unmodified electrode for the same concentration of 2,4-dinitrotoluene. Concentrations of 2,4-dinitrotoluene as low as 10 parts per billion were determined using the modified electrode.