等离子点时Mn(Ⅱ)-HSA金属中心的结构

用紫外光谱研究了等离子点时Ｍｎ（Ⅱ）－ＨＳＡ（Ｈｕｍａｎｓｅｒｕｍａｌｂｕｍｉｎ）金属中心的结构。结果表明：Ｍｎ（Ⅱ）－ＨＳＡ金属中心的配位结构为规则或不规则的四方锥形构型，与生理ｐＨ下存在四方锥→四方平面构型转变不同。Ｍｎ（Ⅱ）的结合位置仍在ＨＳＡ的Ｎ端三肽段，与Ａｓｐ１的α－ＮＨ２，Ｈｉｓ３的咪唑基Ｎ及两个去质子肽氮配位。用配位环境差异可对这两种ｐＨ条件下的不同结果进行解释。     

超声电解氧化Mn(Ⅱ)电流效率的研究

以金属铅作为阴、阳极,超声电解氧化Mn(Ⅱ)成Mn(Ⅲ),比较了超声电解与搅拌电解时的电流效率,得出了超声电解氧化Mn(Ⅱ)的最优化的条件:0.4mol/L MnSO4、7mol/L H2SO4的溶液中,电流密度为80mA/cm2,在 3.5V进行电解.     

Electrooxidation of Mn(Ⅱ) on Pb-Sb-As Electrode in Sulfuric Acid

The electrooxidation of Mn(Ⅱ) on Pb-Sb-As alloy electrode in sulfuric acid has been investigated.In order to make the two steps of indirect electrosynthesis of benzaldehyde carried out in the same sulfuric acid concentration and also obtain high current efficiency of Mn(Ⅱ) to Mn(Ⅲ) and high yield of Mn(Ⅲ) oxidizing toluene to benzaldehyde in the mean time,the electrooxidation of Mn(Ⅱ) in 60% H2SO4 has been studied.Experimental results show that high current efficiency of Mn(Ⅲ) (about 75%) is obtained in 60%H2SO4 at 60℃.The reason affecting the current efficiency of Mn(Ⅲ) is discussed,and it is the coordination of sulfuric acid concentration and electrolytic temperature.The law is found that it is suitable for electrolysis at low temperature when sulfuric acid concentration is low and at high temperature when sulfuric acid concentration is high.     

Mn(I)/MI.(Ⅱ)体系电极的研制

研制出一种适合Mn(Ⅲ)/Mn(Ⅱ)体系的铅三元合金电极,其中w(铅)=98.5%,w(银)=0.5%,w(锑)=1.0%,电解收率达73%,并与铂等电极进行了比较.     

系列Mn(Ⅱ)配合物的光电性能研究

采用水热方法合成了2个Mn(Ⅱ)配合物[Mn(pzdc)( H2O)2]n(1)(H2pzdc=3,5-吡唑二羧酸),[Mn(phen)(pdc)(H2O)2] · H2O(2)(H2pdc=2,5-吡啶二羧酸),通过单晶X-射线衍射确定了配合物的晶体结构.结构分析表明,配合物1属于单斜晶系,P21/c空间群,在晶体中,中心金属Mn(Ⅱ)离子为6配位,是以3,5-吡唑二羧酸为桥连接起来的具有1D无限结构的配位聚合物;配合物2属于三斜晶系,P-1空间群,在晶体中,中心金属Mn(Ⅱ)离子为6配位,是单核结构,氢键将其连接成具有2D结构的配位超分子.在室温下对配合物的IR和UV-Vis-NIR吸收光谱进行了测定和分析指认.而且利用表面光电压光谱研究了配合物的表面光伏性能.结果表明,配合物1和2在300～500 nm范围内呈现出正的光伏响应.并且随着Mn(Ⅱ)离子配位环境不同,光伏响应带数目和强度也明显不同.     

属离子与镉卟啉络合物的置换反应分光光度法测定地下水中的Mn(Ⅱ)

研究了在咪唑存在下,meso-四(4-羧甲氧基苯)卟啉[TCMOPPH2]和Cd(Ⅱ)所形成的卟啉络合物Cd(Ⅱ)-TCMOPP与Mn(Ⅱ)间的置换反应.结果表明,在弱碱性介质(pH;8.O)中,室温条件下该反应能快速完成,且反应产物Mn(Ⅱ)-TCMOPP立即被水中的溶解氧氧化为Mn(Ⅲ)-TCMOPP卟啉络合物.其最大吸收波长在472.0nm.Mn(Ⅱ)的浓度在1.1～110.0,ng/mL范围内服从比尔定律,桑德尔灵敏度为0.5x10-3μg/cm2.该方法具有一定的选择性,应用于油田地下水中Mn(Ⅱ)的测定,结果满意.     

磁性聚合单宁-纤维素树脂的制备及对Mn(Ⅱ) 废水的吸附

以Fe_3O_4作为磁核,单宁酚醛聚合物和纤维素作为包裹材料,环氧氯丙烷为交联剂,经反相悬浮交联聚合法制备磁性聚合单宁-纤维素树脂,并探讨了该树脂对Mn(Ⅱ)吸附性能。结果表明:树脂经包埋Fe_3O_4后具有磁性;树脂对Mn(Ⅱ)离子具备较好的吸附容量,其饱和吸附容量为37.52 mg/g;树脂对Mn(Ⅱ)具有较快的吸附速率,达到吸附平衡的时间为20 min;当Mn(Ⅱ)溶液浓度低于20 mg/L时,经树脂吸附后溶液中残剩Mn(Ⅱ)浓度均低于1.89 mg/L,低于国家污水综合排放要求;该树脂Mn(Ⅱ)废水处理方面具有潜在的应用前景。     

海洋沉积物—水界面邻近新生颗粒对Mn(Ⅱ)氧化速度的影响

模拟海洋沉积物界面邻近条件下,研究了吸附硅酸盐及Cu、Pb、Co、Ni的水合氧化铁颗粒和FeS沉淀对Mn(Ⅱ)氧化反应的影响.在每升含有毫克分子数量级的FeOOH或FeS体系中,测定结果表明,氧化速度与Mn(Ⅱ)浓度为一级反应.在水合氧化铁表面的锰氧化速率常数随着氧化铁吸附硅酸盐量的增加而下降,但吸附重金属的水合氧化铁,其速率常数依然没有显著的变化.在水合氧化铁表面或新生FeS沉淀上,Mn(Ⅱ)氧化反应的速率常数具有相同的数量级.     

Effect of Mn cluster on the formation of superoxide radicals in photoinhibition of photosystem Ⅱ

To further realize the action of superoxide radicals (O₂^{− .}) in photoinhibition of photosystem Ⅱ (PSⅡ), we employed 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap, associated with EPR spectroscopy, to study the effect of illumination time on O₂^{− .} formation during high light photoinhibition in PSⅡ membranes and Mn-depleted PSⅡ membranes. Results indicated that the removal of Mn cluster from PS
membranes has a strong influence on the dynamics of superoxide formation. The relative mechanism was also discussed. These novel findings may further promote the studies of the structure and function of PSⅡ and the mechanism of photoinhibition.     

Mn(Ⅱ)在伊利石(001)面和(010)面吸附的密度泛函研究

为探究Mn(Ⅱ)在伊利石表面的吸附机理,采用密度泛函理论(DFT)模拟Mn(Ⅱ)在伊利石(001)面和(010)面的吸附,研究了活性位、吸附构型、电荷和态密度。结果表明:在(001)面,Mn(Ⅱ)优先吸附于硅氧环空穴处,且与活性氧O_S1形成1个共价键,吸附能为-262.55 kJ/mol;在(010)面,Mn(Ⅱ)与羟基基团的氧原子形成1~3个共价键,随着共价键数量的增加,吸附能增大,吸附的最稳定构型为Mn(Ⅱ)吸附于3个≡Al—OH基团之间的空穴处,吸附能为-533.62 kJ/mol;Mn(Ⅱ)与(001)面和(010)面均存在共价键作用和静电作用,在(001)面的吸附能小于(010)面,且与(001)面以静电作用为主,与(010)面以共价键作用为主;Mn(Ⅱ)与伊利石表面共价键的形成主要是Mn(Ⅱ)的4s轨道与表面O_S的2p轨道间的相互作用。研究结果可为黏土吸附材料的开发和污染土壤的净化提供理论基础。     

Equilibrium dialysis study on the interaction between Cu(Ⅱ) and HSA or BSA

The interaction of Cu(Ⅱ) and human serum albumin (HSA) or bovine serum albumin (BSA) at physiological pH is studied by equilibrium dialysis. The successive stability constants are obtained by non-linear least square methods fitting Bjerrum formula. For both the Cu(Ⅱ)-HSA and Cu(Ⅱ)-BSA systems, the order of magnitude of K 1 and K 2 was found to be ≈10 4 mol -1·dm 3. There are about twenty stoichiometry binding sites found in one HSA or BSA molecule. They can be divided into two or three sets. Results of equilibrium dialysis experiments suggest that there exists one strong metal binding site in both Cu(Ⅱ)-HSA and Cu(Ⅱ)-BSA. It is the imidazol group nitrogen atoms of His 3 that are primarily concerned with copper binding site. After reaching dialysis equilibrium, there is the interaction among the different binding sites, the values of K all deviate from the simple statistical effect except for K-1 and K-2 in both Cu(Ⅱ)-HSA and Cu(Ⅱ)-BSA systems, and the positive cooperative effect is found.     

天然水中Mn(Ⅱ)的光化学荧光催化动力学法测定

叙述了基于Mn(Ⅱ)对酸性铬蓝K光化学反应的催化作用而建立起的一种Mn(Ⅱ)的光化学荧光催化动力学分析的新方法。Mn(Ⅱ)的含量在0～120ng/ml范围内呈良好的线性关系,相关系放为0.998,检测限和变异系数分别为2ng/ml和1.3％,本法已用于直接测定自来水中的Mn(Ⅱ)结果满意,还初步探讨了该反应的机制。     

金属离子与镉卟啉络合物的置换反应分光光度法测定地下水中的Mn(Ⅱ )(英文)

研究了在咪唑存在下,meso四(4羧甲氧基苯)卟啉〔TCMOPPH2〕和Cd(Ⅱ)所形成的卟啉络合物Cd(Ⅱ)TCMOPP与Mn(Ⅱ)间的置换反应.结果表明,在弱碱性介质(pH=80)中,室温条件下该反应能快速完成,且反应产物Mn(Ⅱ)TCMOPP立即被水中的溶解氧氧化为Mn(Ⅲ)TCMOPP卟啉络合物.其最大吸收波长在4720nm.Mn(Ⅱ)的浓度在1.1～1100ng/mL范围内服从比尔定律,桑德尔灵敏度为05×10-3μg/cm2.该方法具有一定的选择性,应用于油田地下水中Mn(Ⅱ)的测定,结果满意.