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1.
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ks、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kf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、kf等均有影响。  相似文献   

2.
The two Schiff base cobalt(II) complexes, CoL1 and CoL2, were synthesized and characterized. The metallomicelle made up of the cobalt(II) complexes and surfactants (CTAB, LSS and Brij35), as mimic peroxidase metalloenzyme, were used in the catalytic oxidation of phenol by H2O2. The mechanism and a kinetic mathematic model of the phenol catalytic oxidation were studied. The acid effect of reaction system, structural effect of the complexes, and effect of temperature on the rate of the phenol oxidation catalyzed by the mimetic peroxidases have been discussed. The results showed that the schiff base cobalt(II) complexes and their metallomicelles as peroxidase mimics exhibit good catalytic activity and similar catalytic character to natural enzyme.  相似文献   

3.
Two cobalt(Ⅱ) complexes of the Schiff base with morpholino or aza-crown ether pendants, CoL^1 and CoL^2, as mimic hydrolytic metalloenzyme, were used in catalytic hydrolysis of carboxylic ester (PNPP). The analysis of specific absorption spectra of the hydrolytic reaction systems indicates that key intermediates, made up of PNPP and Co(Ⅱ) complexes, have been formed in reaction processes of the PNPP catalytic hydrolysis. The mechanism of PNPP catalytic hydrolysis has been proposed based on the analytic result of specific absorption spectrum. A kinetic mathematical model, applied to the calculation of the kinetic parameter of PNPP catalytic hydrolysis, has been established based on the mechanism proposed. The acid effect of buffer solution, structural effect of the complexes, and effect of temperature on the rate of PNPP hydrolysis catalyzed by the complexes have been also discussed.  相似文献   

4.
香草醛缩多胺Schiff碱Co(II)配合物固相合成及氧合性能研究   总被引:4,自引:0,他引:4  
肖芙蓉  陈鹭  王吉德  武荣兰  岳凡  李静 《化学学报》2006,64(15):1517-1522
采用固相反应合成了三个新的席夫碱钴(II)配合物, 在室温下, 将其与O2作用, 1 mol配合物吸收2 mol O2, 得到三种固态氧合配合物[Co•(L1)2•(O2)2](NO3)2•2H2O [L1N,N-二(4-羟基-3-甲氧基苯亚甲基)二乙烯三胺], [Co•(L2)2•(O2)2](NO3)2•2H2O [L2N,N-二(4-羟基-3-甲氧基苯亚甲基)三乙烯四胺]和[Co•(L3)2•(O2)2](NO3)2•2H2O (L3N,N-二(4-羟基-3-甲氧基苯亚甲基)四乙烯五胺]. 通过元素分析、红外光谱、核磁共振氢谱(1H NMR), TG/DTA、摩尔电导率、紫外等测试手段确定了氧合配合物的组成. 采用失重法测定了氧合配合物中的配位氧, 确定1 mol钴配合物吸收2 mol O2, 其中1 mol O2用来和钴离子配位形成超氧配合物.  相似文献   

5.
A novel and practical catalytic method for efficient and highly selective oxidation of a wide range of benzylic, allylic, aliphatic, primary, and secondary alcohols to the corresponding aldehydes and ketones using tetrabutylammonium peroxomonosulfate catalyzed by tetradentate Schiff base–MnIII complexes has been developed. Electron‐deficient and hindered alcohols required longer reaction times for oxidation in this catalytic system. The electron‐poor and hindered salicylidene ring of the ligand enhanced the catalytic activity and stability of Mn catalysts. The desired turnover numbers obtained in the oxidation reactions indicated the high efficiency and relative stability of these simple Schiff base complexes in this catalytic system.  相似文献   

6.
席夫碱及其络合物的可逆热致变色材料   总被引:15,自引:0,他引:15  
对具有可逆的热致变色的席夫碱及其络合物的分类、合成、变色机理以及发展前景等进行了回顾和探讨。  相似文献   

7.
冠醚化对双Schiff碱钴(Ⅱ)配合物催化氧化性能的影响   总被引:6,自引:0,他引:6  
合成了冠醚化钴(Ⅱ)Schif碱配合物1c及其相关类似物1b,测定了它们的氧加合常数,考查了它们对异丙苯的催化氧化性能,并与未冠醚化的类似物1a作比较,讨论了1c分子中的冠环对催化氧化性能的影响  相似文献   

8.
新型双核席夫碱配合物的合成及谱学性质   总被引:1,自引:0,他引:1  
Eight novel binuclear tetradentate Schiff base complexes (M=Cu(Ⅱ),Ni(Ⅱ),Zn(Ⅱ)) are synthesized. The structure of complexes is two discrete Schiff base unit bridged. The complexes were condensed from series sub-stituent Ketones (5-chloro-2-hydroxybenzophenone, 5-methyl-2-hydroxy-benzophenone, 5-Bromo-2-hydroxybenzop- henone) and dialdehydes (5,5′-methylene-disalicylaldehyde) with the amino group of 1,2-diaminobenzene, and by Metal ion as template. The compounds were characterized by elemental analyses, FT-infrared spectra, Raman, 1H NMR, UV-vis electronic spectra, EPR spectra. The FT-infrared spectra and Raman spectra of complexes were compared and discussed. The UV-vis election spectra, 1H NMR and EPR spectra of complexes have also been attributed and minutely analyzed.  相似文献   

9.
The compounds, C21H27N4O3(L1) and C21H27N7(L2), is a tripodal Schiff base that was obtained from the reaction of tris(2-aminoethyl)amine (tren) and furan-2-carbaldehyde and pyrole- 2- carbaldehyde. The tripodal Schiff bases and their oxovanadium complexes have been characterized on the basis of the results of the elemental analysis, magnetic susceptibility measurements and spectroscopic studies FT-IR, 1H-NMR, UV–Vis, ESR, magnetic moment and thermal analysis (TGA). Job's method of continuous variation shows 3:2 metal to ligand ratio.  相似文献   

10.
采用直接合成法用异烟酰肼、水杨醛合成了异烟酰肼缩水杨醛Schiff碱,并以此为配体合成了Zn(Ⅱ)、Co(Ⅲ)、Ni(Ⅱ)的配合物.对配合物进行了元素分析,红外光谱,紫外光谱,差热-热重分析及摩尔电导的测试等表征,推测配合物的组成分别为[Zn(H2O)L],[Co(H2O)2(HL)2]NO3-H2O,[Ni(H2O)2HL]NO3,其中L=C13 H9O2N3.  相似文献   

11.
以3-甲基-4-氨基-5-乙氧羰基甲硫基-1,2,4-三唑为原料,与取代芳醛合成9种3-甲基-4-(X-取代基苯亚甲基氨基)-5-乙氧羰基甲硫基-1,2,4-三唑席夫碱化合物a~i。 产物结构经1H NMR、IR和MS等技术手段确证。 其中化合物3-甲基-4-(4-羟基苯亚甲基氨基)-5-乙氧羰基甲硫基-1,2,4-三唑h进一步经X射线单晶衍射得到其晶体结构(CCDC:910927):C14H16N4O3S,Mr=320.37,Orthorhombic,P2(1)2(1)2(1)/n,a=0.9220(10) nm,b=1.5823(17) nm,c=2.1667(2) nm,V=3.161(6) nm3,Z=8,F(000)=1344。 化合物对4种植物病原菌的初步生物活性测试结果(EC95值)表明,化合物d、e、f对供试菌种西瓜枯萎病和小麦赤霉病的抑菌活性优于对照原药三唑酮。  相似文献   

12.
13.
单核Mn(III)-Shiff碱配合物的晶体结构与性质   总被引:1,自引:0,他引:1  
报导了两个Schiff碱配体的单核Mn(Ⅲ)配合物([Mn(Ⅲ)(L1)(H2O)]4CIO。·ZH。O(1)和[Mn(ffi)(LZ)厂Ic。·ZH。O(2》的合成、晶体结构及性反X一衍射晶体结构分析证实:配合物1的晶体属于正交晶系,Pna21空间群.其晶胞参数为α=10.932(7)A,b=22.393(5)A,c=8.960(3)A,V=2193(1)A3,Z=4.2的晶体属于正交晶系,P212121空间群,α=17.345(3)A,b=17.905(2)A,c=7.789(1)A,V=2418.9(6)A3,Z=4.电化学研究结果显示:配合2是稳定的电化学产物,而1在电场作用下容易歧化.由此说明配位环境是影响化合物稳定性的重要因素.  相似文献   

14.

The oxidation of p-xylene to p-toluic acid with air at 110°C under normal atmospheric pressure occurs efficiently in the presence of crown Mn(III) Schiff base complexes [Formula: See Text] (n=1-4). Significant conversion levels (up to 75%) and selectivity (up to 92-96%) are obtained; the effect of the azacrown ether pendants in Mn(III) Schiff base complexes on the oxidation of p-xylene are also investigated by comparison with the crown-free analogues [Formula: See Text] Moreover, addition of alkali metal ions accelerates the rate of conversion of p-xylene to p-toluic acid.  相似文献   

15.
The reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride was used as a model to test the catalytic activity of copper(II) complexes containing N,O-chelating Schiff base ligands. In this study, a series of copper(II) complexes containing respective Schiff base ligands, N′-salicylidene-2-aminophenol (1), N′-salicylidene-2-aminothiazole (2), and N,N′-bis(salicylidene)-o-phenylenediamine (3), were synthesized and characterized by elemental analysis, Fourier transform infrared (FT-IR), UV-Visible (UV-Vis) and electron paramagnetic resonance (EPR) spectroscopies. The results from the 4-nitrophenol reduction showed that 3 has the highest catalytic activities with 97.5% conversion, followed by 2 and 1 with 95.2% and 90.8% conversions, respectively. The optimization of the catalyst amount revealed that 1.0 mol% of the catalyst was the most optimized amount with the highest conversion compared to the other doses, 0.5 mol% and 1.5 mol%. Recyclability and reproducibility tests confirmed that all three complexes were active, efficient, and possess excellent reproducibility with consistent catalytic performances and could be used again without a major decrease in the catalytic activity.  相似文献   

16.
Tin(IV) complexes of the series of dianionic terdentate Schiff bases N‐[(2‐pyrroyl)methylidene]‐N′‐tosylbenzene‐1,2‐diamine, (H2L1), N‐[(2‐hydroxyphenyl)methylidene]‐N′‐tosylbenzene‐1,2‐diamine (H2L2) and some R substituted 2‐{[(2‐hydroxyphenyl)imino]methyl}phenols [R = H (H2L3), 4,6‐(OCH3)2 (H2L4), 3‐(OC2H5) (H2L5) and 3,5‐Br2 (H2L6)] have been synthesized. The compounds were obtained by the electrochemical oxidation of a tin anode in a cell containing an acetonitrile solution of the corresponding ligand. The complex [SnL12] was also obtained by reaction of SnCl2·2H2O and H2L1 in methanol in the presence of triethylamine. The crystal structure of the ligand [H2L6] and the complexes [SnL12] (1) , [SnL22] (2) , [SnL32] (3) and [SnL62] (6) were determined by X‐ray diffraction. In the complexes, the tin atom is in an octahedral environment coordinated by two dianionic terdentate ligands. Spectroscopic data for the complexes (IR, 1H and 119Sn NMR and mass spectra) are discussed and related to structural information.  相似文献   

17.
As a continuation of our previous studies on copper(II) complexes with a bidentate Schiff base derived from 5-bromosalicylaldehyde and -aminopyridine, we have investigated the electronic spectra of the cobalt(II) complex with this ligand. The complex is a red crystalline compound soluble in common solvents, such as chloroform, dioxane, dimethyl formamide, dimethyl sulfoxide, and methanol. The time-elapsed spectral measurements of the complex and ligand, as well as conductivities of the complex in chloroform and dioxane solutions, are presented and discussed. Molar conductivities indicate that the complex exists as a nonelectrolyte in nonpolar solvents and as a 1:1 or 1:2 electrolyte in polar solvents. The ligand-field parameters (CFM/AOM) for the complex in chloroform solution are estimated and discussed.  相似文献   

18.
合成了双水杨醛缩乙二胺Schiff碱(SALEN)与钴的配合物Co(SALEN)(NO3)2.3H2O及镧系-钴的异核配合物LnCo(SALEN)2(NO3)5.2H2O(Ln=La,Nd,Sm,Gd,Yb,Y)以紫外红外光谱,特别是HNMR是EPR波谱等方法研究了它们在组成、结构和配位等方面的异同,中讨论了配合物EPR谱在不同溶剂中峰宽的相对关系,配合物在晶体场强度及Gd^3+周围局部对称性等  相似文献   

19.

Two Schiff base Mn(III) complexes containing polyether side chain were synthesized and characterized. The catalytic hydrolysis of p‐nitrophenyl picolinate (PNPP) by the two complexes in the buffered CTAB micellar solution in the pH range of 6.60–8.20 was investigated kinetically in this study. The influences of acidity, temperature, and structure of complex on the catalytic cleavage of PNPP were also studied. The mechanism of PNPP hydrolysis catalyzed by Schiff base manganese(III) complexes in CTAB micellar solution was proposed. The relative kinetic and thermodynamic parameters were determined. Comparied with the pseudo‐first‐order rate constant (k 0) of PNPP spontaneous hydrolysis in water, the pseudo‐first‐order rate constants (k obsd) of PNPP catalytic hydrolysis are 1.93×103 fold for MnL1 2Cl and 1.06×103 fold for MnL2 2Cl in CTAB micellar solution at pH=7.00, T=25°C, and [S]=2.0×10?4mol · dm?3, respectively. Furthermore, comparing the k obsd of PNPP catalytic hydrolysis by metallomicelles with that of PNPP hydrolysis catalyzed only by metal complexes or CTAB micelle at the above‐mentioned condition, metallomicelles of MnL2(L=L1, L2) Cl/CTAB exhibit notable catalytic activities for promoting PNPP hydrolysis, and MnL1 2Cl/CTAB system is superior in promoting cleavage of PNPP relative to MnL2 2Cl/CTAB system under the same experimental conditions. The results indicate that the rate of PNPP catalytic cleavage is influenced by the structures of the two complexes, the acidity of reaction systems, and the solubilization of PNPP in CTAB micelles.  相似文献   

20.
Two symmetrical double aza‐crowned Schiff base cobalt(II) complexes were synthesized and characterized, and the metallomicelle made up of the cobalt(II) complexes and surfactant, as mimic hydrolytic metalloenzyme, was used in catalytic hydrolysis of bis(4‐nitrophenyl) phosphate (BNPP). The analysis of specific absorption spectrums of the hydrolytic reaction systems indicated that key intermediates made up of BNPP and Co(II) complexes are formed in reaction processes of the BNPP catalytic hydrolysis. In this article, the mechanism of BNPP catalytic hydrolysis has been proposed based on the analytic result of specific absorption spectrum. A kinetic mathematical model, for the calculation of the kinetic parameter of BNPP catalytic hydrolysis has been established based on the mechanism proposed. The acid effect of reaction system, the structural effect of the complexes, the effect of surfactant micelles and the effect of temperature on the rate of BNPP hydrolysis catalyzed by the complexes have been discussed.  相似文献   

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