Electrochemical polymerization of nano-micro sheaf/wire conducting polymer poly[Ni(salen)] for electrochemical energy storage system

<正>The polymer of complex[Ni(salen)],(N,N'-ethylenebis(salicylideneaminato) nickel(H)),was prepared on graphite electrode by the route of linear sweep potential method.The nano-micro sheaf/wire structures of poly[Ni(salen)]have been obtained by adjusting the polymerization sweep rate of 5,20 and 40 mV·s~(-1).The polymer prepared at 20 mV·s~(-1) had nanoscaled wire structure of ca.100 nm in diameter.The good electrochemical reversibility of poly[Ni(salen)]was investigated by cyclic voltammetry and galvanostatic test in 1.0 mol/L Et_3MeNBF_4/acetonitrile solution.The initial specific gravimetric capacitance of poly[Ni(salen)]at the current density of 0.1 mA·cm~(-2) reached 270.2 F·g~(-1),however,the cycle stability needs to be improved.     

Electropolymerization of Ni(salen) on carbon nanotube carrier as a capacitive material by pulse potentiostatic method

The composites of poly[Ni(salen)] and multi-walled carbon nanotube(MWCNT) were synthesized by pulse potentiostatic method.The composites were characterized by field emission scanning electron microscopy,Fourier transform infrared spectra,and electrochemical impedance spectroscopy.The wrapping of carbon nanotubes with poly[Ni(salen)] varied significantly with anodic pulse duration.Variance of structure of poly[Ni(salen)] caused by anodic pulse duration affected the ability of absorption to solvent molecules or solvated ions,which was indicated by ν(C≡N) intensity.The ability to store/release charge of poly[Ni(salen)] caused by redox switching was evaluated in the form of low-frequency capacitance.Correlations of chargetransfer resistance/ionic diffusion resistance with potential and anodic pulse duration were investigated.     

维生素B1的电化学聚合及催化作用

用循环伏安法在石墨电极上制备了VB1聚合膜修饰电极,VB1聚合膜在pH5的PBS中有一对氧化还原峰,峰电位Epd=350mV,Epc=325mV,峰电流与扫描速率的平方根成正比,表明电子在膜中的传递为扩散控制,且聚合膜与VB1单体有不同的电化学性质。实验表明VB1聚合膜对多巴胺、肾上腺素等神经递质有显著的电催化作用。     

电化学聚合制备含富勒烯交联聚合物薄膜及超级电容器应用

通过N-烷基咔唑基团修饰富勒烯C_(60),获得了3种不同取代基数目的富勒烯衍生物2Cz-C_(60)、4Cz-C_(60)和6Cz-C_(60);3种单体具有高的电化学聚合活性,通过阳极电化学聚合得到了3种结构明确的聚合物(Poly[2Cz-C_(60)]、Poly[4Cz-C_(60)]和Poly[6Cz-C_(60)]),它们同时在工作电极上沉积得到了厚度精确可控的交联薄膜,其生长速度分别为1.88、1.70和2.61 nm/圈.电化学聚合过程中沉积薄膜快速而均匀的生长,为瞬间成核、岛状生长模式,并最终形成球状堆积的交联薄膜.经循环伏安法测试表明沉积薄膜有多对氧化还原峰,具有可逆的n-型与p-型双极性掺杂特性,并表现出可逆的和快速电荷传递的氧化还原反应特性.另外这种富勒烯交联薄膜作为超级电容电极材料也表现出了相当可观的电荷储存能力.     

磷钼酸修饰的铂电极对二甲醚氧化的电催化作用

利用循环伏安扫描法制备了磷钼酸(H3PMo12O40)修饰的铂电极.在制备修饰电极时,随着扫描次数的增加,磷钼酸的氧化还原峰电流增大,但最终获得稳定的重现性好的磷钼酸修饰的铂电极.通过循环伏安法研究了该修饰电极对二甲醚氧化的电催化反应.结果表明,与未修饰的铂电极相比,磷钼酸修饰的铂电极电催化氧化二甲醚的起始氧化电位负移50 mV,氧化峰电位负移35 mV,氧化峰电流密度提高了1.86倍,这表明修饰电极的电催化活性有了很大的提高.同时,电位负扫时,二甲醚在425 mV(vsSCE)处出现氧化峰,表明二甲醚在修饰电极上的电氧化机理可能发生了改变.实验还发现,制备修饰电极时,降低扫速会提高还原物质杂多蓝的吸附量,但过多的修饰物质会降低铂的活性位数目,反而降低了对二甲醚氧化的电催化作用.     

聚中性红/Ni2+修饰碳糊电极对葡萄糖的电催化氧化研究

采用循环伏安法(CV)在碳糊电极(CPE)上通过共聚的方式电聚合制备了聚中性红/Ni2+修饰碳糊电极(Ni2+/PNR/CPE),该修饰电极在0.1mol.L-1NaOH溶液中扫描活化后,在0.531V/0.348V处有一对明显的氧化还原峰,表明Ni2+离子已掺杂于聚合膜中。分别运用扫描电子显微镜(SEM)和X射线能谱仪(EDS)观测并分析了聚合膜的表面形貌及组成。研究结果表明:Ni2+/PNR/CPE在碱性介质中对葡萄糖的氧化具有明显的电催化作用。探讨了最佳实验条件;计算了葡萄糖的部分动力学参数:电荷转移系数(α=0.6970)及电极反应速率常数(k=2.003×103cm3.mol-1.s-1);葡萄糖的氧化峰电流与浓度在1.0×10-5mol.L-1～1.0×10-2mol.L-1范围内表现出良好的线性关系,检出限为5×10-6mol.L-1(S/N=3),该修饰电极制备方法简单、灵敏度高、稳定性好,用于实际样品中葡萄糖的含量分析,结果令人满意。     

邻苯二胺、邻氨基酚的电化学聚合及聚合的膜性质

邻苯二胺(ODB), 邻氨基酚(OAP)在酸性水溶液中易电聚合, 可形成致密的聚合膜。聚邻苯二胺(PODB)在PH<4时具有电活性, 其氧化还原反应与电变色效应对应。聚邻苯二胺,聚邻氨基酚(POAP)膜电极电位在pH=4～10范围对pH有Nernst响应, 电极系数分别为59mV/pH和57mV/pH。响应时间小于3分钟。PODB, POAP膜能与Ni~(2+), Co~(2+)过渡金属离子形成稳定的聚合络合膜。此膜在碱性介质中具有稳定的循环伏安行为, 膜中的金属离子可被H~+交换。PODB电极的—NH_2基可再修饰引入醌/氢醌功能团。     

聚灿烂甲酚蓝修饰玻碳电极的制备及电化学性质

在含灿烂甲酚蓝的磷酸缓冲溶液中,用循环伏安法扫描.在经预处理的玻碳电极上形成了聚合物薄膜.在-0.7V-+0.9V(vsSCE)的扫描电位范围和弱碱性介质中形成的薄膜具有较高电活性和稳定性.制备好的聚灿烂甲酚蓝修饰电极在磷酸缓冲溶液的循环伏安曲线有两对氧化还原峰,峰电位随pH升高而向负电位方向移动.该电极对NADH的电化学氧化有催化作用,使其氧化电位负移了270mV并增大了氧化峰电流.     

ACPMA/BPO引发甲基丙烯酸甲酯聚合及其动力学

以4,4′-偶氮二[4-氰基戊酰(对-二甲氨基)苯胺](ACPMA)/过氧化二苯甲酰(BPO)为氧化还原引发体系,研究了甲基丙烯酸甲酯(MMA)在N,N-二甲基甲酰胺(DMF)中的聚合及其动力学行为.考察了聚合反应温度、单体浓度、ACPMA浓度和BPO浓度对聚合反应速率和聚合物分子量的影响,测定了反应级数和聚合反应的活化能.结果表明,在一定范围内,聚合反应速率随单体浓度增大、ACPMA浓度增大、BPO浓度增大和反应温度的升高而增大;聚合物分子量随单体浓度的增大而增大,随ACPMA浓度的增大、BPO浓度增大和反应温度的升高而降低.该体系具有氧化还原引发体系的特征,其引发MMA的聚合速率方程为Rp=K[ACPMA]0.57     

Sn（Ⅱ）／Sn（Ⅳ）对PtSn／C乙醇电化学氧化活性的影响

在乙二醇共还原H2PtCl6和SnCl2的过程中加入Ni(NO3)2作为助剂制备了PtSn/C-Ni催化剂. 程序升温还原实验检测到该催化剂中存在Sn(Ⅱ)/Sn(Ⅳ)氧化还原电对. 线性扫描、单电池性能测试和CO溶出实验表明,提高催化剂中Sn(Ⅱ)/Sn(Ⅳ)的比值能显著提高催化剂的乙醇电化学氧化活性和抗CO中毒能力. 催化剂电催化活性提高的原因可能是Sn(Ⅱ)/Sn(Ⅳ)电对加快了(OH)ads 物种在催化剂中的传递速率,促进了乙醇电化学氧化过程中产生的类CO中间物种在Pt表面的氧化.     

稀土Schiff碱配合物催化烷基异氰酸酯室温聚合

利用Schiff碱稀土配合物Ln（H2Salen）2Cl3·2C2H5OH与AI（i—Bu）3组成的催化体系催化烷基异氰酸酯室温聚合,详细考察了催化剂组成以及聚合条件等对烷基异氰酸酯聚合的影响,并研究了己基异氰酸酯的聚合动力学．以La、Nd、Sm和Gd四种稀土元素为代表,合成了相应的Schiff碱配合物,结果表明轻稀土体系比重稀土体系好,La的聚合活性最高．在-40℃-40℃很宽的聚合温度范围内,可以得到分子量分布窄（MWD=1．50～2．40）的高分子量聚异氰酸酯,20℃为最佳的聚合温度．己基异氰酸酯的最佳聚合条件为：[AI]／[La]=30（摩尔比）,[n-HexNCO]／[La]=100,[n—HexNCO]=3．43mol／L,甲苯溶液中20℃聚合12h,聚合物收率74．0％,聚合物黏均分子量高达73．5×10^4,数均分子量40．2×10^4,MWD=1．79．聚合动力学研究表明己基异氰酸酯聚合反应对单体浓度和催化剂浓度都是一级关系,聚合反应活化能为43．64kJ／mol．     

The Effect of Electrode Potential on the Conductivity of Polymer Complexes of Nickel with Salen Ligands

The influence of the electrode potential on the electric conductivity of polymer complexes of nickel with salen-type ligands (where salen is N,N′-ethylene-bis(salicylideneimine)) differing by substituents in ligand′s benzene ring is studied in the course of measuring cyclic voltammograms. The highest electron conductivity is observed for the film of poly[N,N′-ethylene-bis(3-methoxysalicylideneiminato) nickel(II)] (poly[Ni(CH₃OSalen)]) in 1 M LiPF₆ solution in the ethylene carbonate-diethylcarbonate mixture (EC: DEC = 1: 1). Poly[N,N′-ethylene-bis(3-methyl-salicyleneiminato) nickel(II)] (or poly[Ni(CH₃Salen)]) was found to have the widest potential range of electronic conductivity. Conditions are selected for synthesizing films from solutions of the corresponding monomers in 1 M LiPF₆ EC: DEC electrolyte. The electrode potential intervals suitable for the use of poly[Ni(CH₃Salen)] as the buffer interlayer between the aluminum substrate and the cathode mass in lithium-ion batteries for protecting the latter against overcharge are found.

     

手性Salen-Ni(Ⅱ)络合物的ECD光谱及其绝对构型关联:可见区第一ECD吸收带的指纹作用

对系列手性salen-Ni(Ⅱ)络合物的电子圆二色(ECD)光谱及其绝对构型关联进行了概述.根据晶体结构和对固、液ECD光谱的表征,结合理论计算,着重探讨了准平面型手性[Ni(salen)]的固态结构及其在溶液中的绝对构型和优势构象.在此基础上通过若干实例说明了平面四方形[M(salen)]络合物两种绝对构型命名法,并给出了我们的建议.对[Ni(sal-R, R-chxn)] [sal-R, R-chxn = (R, R)-N, N'-双(亚水杨基)-1, 2-二亚氨基环己烷]的二氯甲烷溶液ECD光谱的计算结果表明,可见区第一个ECD吸收带主要是π →d荷移跃迁(LMCT)所致,而不是通常认为的d-d跃迁: [Ni(sal-R, R-chxn)]的绝对构型为Λ,其在可见区第一个ECD吸收带为正.将此ECD指纹应用于具有“闭壳层”电子结构的其它平面型手性[Ni(salen)]和六配位trans-[Co^Ⅲ(salen)L₂]络合物的绝对构型指认,具有一定的普适性.本文的研究结果对于深入理解手性[M(salen)]络合物的配位立体化学、手征光学性质及其手性识别和不对称催化机理具有重要科学意义.     

Nafion基氧化还原聚合物在空气中的电荷传输性能

利用三明治电池和伏安法测试了不同制备条件的Nafion基氧化还原聚合物膜在空气中的电荷传输性能. 研究结果表明, 混合适量聚乙二醇(PEG)的Nafion基金属联吡啶配合物{Nafion[M(bpy)2+3, PEG](M=Ru, Fe)}膜的表观电荷传递扩散系数(Dct)达到10-6-10-7 cm2·s-1 , 电子或空穴迁移率(μ)达到10-4-10-5 cm2·V-1·s-1. 在导电玻璃(ITO)电极与Nafion基氧化还原聚合物膜界面引入一层导电聚苯胺(PANI)后, 降低了其接触电阻, 使氧化还原聚合物膜的Dct提高至10-5-10-6 cm2·s-1, μ提高至10-3-10-4 cm2·V-1·s-1, 且工作电流提高了近两个数量级. 该固态氧化还原聚合物膜的性能比较稳定, 在空气中放置30天后其Dct和μ降低得很少.     

Synthesis, Crystal Structure and Electrochemistry Properties of a (N,N''-Ethylene-bis(salicylaldiminato)) Nickel(Ⅱ) Complex, [Ni2(salen)2]·NCS-NH4

A new Ni(Ⅱ) complex [Ni2(salen)2]·(NCS)·NH4 (salen = N,N'-bis(salicylidenea-mino)ethanato) has been prepared and structurally characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. It crystallizes in the orthorhombic system, space group Pbca with a = 16.8725(13), b = 19.0046(15), c = 20.0583(16) (A), Z = 8, V = 6431.8(9) (A)3, C33H32N6Ni2O4S1, Mr= 726.13, Dc = 1.500 g/cm3, F(000) = 3008, μ = 1.284 mm-1, the final R = 0.0394 and wR = 0.0767 for 4449 observed reflections with Ⅰ＞2σ(Ⅰ). The complex involves a N,N'-ethylene-bis(salicylaldiminato) Schiff base, an isothiocyanato anion and an ammonium cation. The nickle(Ⅱ) ion adopts a distorted square coordination geometry with N2O2 set of Schiff base ligand. The complexes are linked into a dimmer via intermolecular hydrogen bonds and the [Ni(salen)] moieties are connected together to form a 2-D layer structure by intermolecular N-H…O hydrogen bonds and π-π stacking. Cyclic-voltammetry method was used to characterize electrochemically the complex.     

A combined electrochemical quartz-crystal microbalance probe beam deflection (EQCM-PBD) study of solvent and ion transfers at a poly

The oxidative polymerisation of the complex2,3-dimethyl-N,N'-bis-(salicylidene)butane-2,3-diaminatonick-el(II), [Ni(saltMe)], was monitored by the electrochemical quartz microbalance (EQCM) and crystal impedance techniques. Polymerisation efficiency was maintained throughout deposition of a film, which behaved rigidly, on the electrode. A combined EQCM-PBD (probe beam deflection) study of the redox process of the film exposed to a monomer-free solution of 0.1 M tetraethylammonium perchlorate (TEAP) in acetonitrile showed an electroneutrality mechanism dominated by anion movement accompanied by co-transfer of solvent above 0.8 V. The individual contributions of all the mobile species involved in the redox switching of the poly[Ni(saltMe)] film were determined quantitatively by temporal convolution analysis; the estimated solution-phase diffusion coefficient of the exchanged species was 1.24 x 10(-5) cm2s-1.     

新型氰基桥联二维配位聚合物{[Fe(salen)]_2[Ni(CN)_4]}_n的合成、晶体结构和磁性质

将[Fe(salen)NO_3]的甲醇溶液和K_2[Ni(CN)_4]·H_2O水溶液通过H管扩散反 应,得到了一个新型氰基桥联配位聚合物{[Fe(salen)]_2[Ni(CN)_4]}_n (H_2salen为N,N'-二水杨醛缩乙二胺席夫碱)。该化合物属四方晶系。空间群 P4/ncc,晶胞参数为a=b=1.4216(2)nm, c=1.7471(5)nm, V=3.5308(12)nm~3,Z=.该 配合物通过Ni-CN-Fe(salen)-NC-Ni链连接形成二维枕形网格结构,其中键长Ni-C 0.1876(3)nm, Fe-N 0.2170(3) nm, 键角Fe-N-C 164.9(3)°,Ni-C-N 178.9(4) °;金属中心Ni(III)和Fe(III)分别具有正方形和畸形变八面体配位构型。变温磁 化率研究表明,配合物存在分子内反铁磁相互作用,其Fe(III)…Fe(III)交换积分 为-0.041cm~(-1).     

Anion-dependent construction of two hexanuclear 3d-4f complexes with a flexible Schiff base ligand

Two hexanuclear 3d-4f Ni-Eu and Cu-Eu complexes [Eu(4)Ni(2)L(2)(OAc)(12)(EtOH)(2)] (1) and [Eu(4)Cu(2)L(2)(OAc)(12)]·2H(2)O (2) are reported which are formed from the salen type Schiff-base ligand H(2)L (H(2)L = N,N'-bis(3-methoxysalicylidene)butane-1,4-diamine). In both complexes, four Eu(3+) cations are bridged by eight OAc(-) groups and the chain is terminated at each end by two ML (M = Ni and Cu) units. The structures of 1 and 2 were determined by single crystal X-ray crystallographic studies and the luminescence properties of the free ligand and metal complexes in solution were measured.