过渡元素杂多钨硅酸盐氧化还原性质的研究

本文通过极谱和循环伏安法,结合紫外光谱和X射线光电子能谱,研究了过渡元素钨硅杂多酸盐Kn[SiM(H2O)W11O39](M=Mn^2^+,Fe^3^+,Co^2^+,Ni^2^+,Zn^2^+,Cd^2^+)在溶液中的氧化还原性质,提出了它们的还原机理.杂多阴离子的极谱半波还原电位E1/2的顺序为Ni^2^+>Co^2^+>Zn^2^+>Fe^2^+>Mn^2^+,发现杂多阴离子的E1/2与其组分中的过渡元素的电负性X和过渡金属离子与水合电子反应速率常数的对数logke-分别有线性关系,讨论了过渡元素对杂多阴离子氧化还原性的影响.     

杂多阴离子柱撑水滑石的合成、热稳定性、酸碱性研究

采用水溶液中阴离子直接交换法合成了过渡金属单取代Keggin结构杂多阴离子SiW11M(H2O)O39^6^- (M=Mn^2^+, Fe^2^+, Co^2^+, Ni^2^+, Cu^2^+,Zn^2^+)柱撑水滑石。用元素分析、XRD和IR对产物的组成与结构进行了表征。XRD结果给出柱撑产物的底面间距达1.47nm。DTA结合不同温度下焙烧样品的XRD、IR研究表明, 柱撑水滑石在低于250℃时脱除物理吸附水和层间水; 在400~500℃之间脱除层上羟基, 形成一个无定形的混合氧化物状态; 在600℃以上无定形态结晶为晶态氧化物混合物。异丙醇探针反应表明, 柱撑水滑石具有高于水滑石前驱体和相应杂多酸盐的催化活性, 且同时存在酸碱两类催化活性中心, 但酸中心明显较强。     

特烯合成中金属子的模板效应

本文报道了以乙醇为溶剂, 呋喃与丙酮在浓盐酸催化下缩合生成2,2,7,7,12,12,17,17-八甲基-21,22,23,24-四氧 特烯, 采用固定反应时间, 比较产率的方法, 研究Sn^2^+, Sb^3^+, Al^3^+, Zn^2^+等金属离子对合成 特烯的模板效应的影响.     

特烯合成中金属子的模板效应

本文报道了以乙醇为溶剂, 呋喃与丙酮在浓盐酸催化下缩合生成2,2,7,7,12,12,17,17-八甲基-21,22,23,24-四氧 特烯, 采用固定反应时间, 比较产率的方法, 研究Sn^2^+, Sb^3^+, Al^3^+, Zn^2^+等金属离子对合成 特烯的模板效应的影响.     

多吡啶钌(Ⅱ)配合物化学发光性质研究

详细研究了Ru(bpy)3^2+,Ru(bpy)2(dppx)^2+,Ru(bpy)2(dppz)^2+,Ru(phen)3^2+,Ru(phen)2(dppx)^2+和Ru(phen)2(dppz)^2+六个多吡啶钌(Ⅱ)配合物的化学发光性质,筛选出Ru(bpy)3^2+和Ru(phen)3^2+两种性能优良的化学发光试剂;并探讨了它们发光的可能机理和影响因素,为钌(Ⅱ)配合物在化学发光分析中的应用提供了可供参考的理论依据。     

杂多阴离子的相转移化学 Ⅰ.取代的Keggin及Dawson结构杂多阴离子在非极性溶剂中的溶剂化行为研究

利用四庚基溴化铵将Keggin结构的杂多阴离子ZW~1~1O~3~9M(H~2O)^n^-(Z=Si,Ge,P,M=Ni^2^+,Cu^2^+,Cr^3^+,Co^2^+,n=4～6)和Dawson结构的杂多阴离子P~2W~1~7O~6~1M(H~2O)^n^-(M=Ni^2^+,Cu^2^+,Cr^3^+,Co^2^+,n=7,8) 从水溶液中转移至非极性溶剂(苯或甲苯)中,并观察到在水溶液中难以进行的配位水的脱去反应,形成配位不饱和的杂多阴离子.当加入Lewis碱如丙酮,吡啶等,可迅速恢复饱和配位,其电子吸收光谱也相应变化,基本恢复到配位饱和时的数值,有ESR信号.实验表明,在非极性溶剂中,配体之间相互进行的取代反应,吡啶的配位能力最强, 发生了取代反应ZW~1~1O~3~9M(L)^n^-+Py→ZW~1~1O~3~9M(Py)^n^-+L(L=丙酮,乙腈等).同时我们也研究了温度,杂多阴离子浓度,惰性气体流量对杂多阴离子在非极性溶剂中的溶剂化行为的影响,得到了相转移的一般规律,为杂多阴离子在非极性溶剂中的催化研究提供了理论依据     

脂肪族方酰胺多齿配体的合成

曾合成并研究了以1,3-双苯氨基方酸内翁盐为骨架,在苯环的2-位对称引入多甘醇醚链的双臂型方酰胺多齿配体,其中某些化合物既能作为配体对UO~2^2^+及ZγO^2^+等刚性离子配位,又能与配体NH~3发生作用,以它作为中性载体的氨选择性电极可望用于NH~3的测定。在脂肪胺的方酸内翁盐型多齿配体中,因无芳环的共轭,四碳环及其上氧之电荷状态将有所不同,这必将影响整个分子的性质。本文对这类化合物的合成进行探索,找到了行之有效的合成方法,并由此制得了九个方酰胺配体5(a～i),其中5i可作为聚酰胺等的稳定剂,其余均未见文献报道。     

中性载体ETH129推动金属离子在水/硝基苯界面的转移

本文用循环伏安法发现了中性载体ETH129(N, N, N', N'-四环己基-3-氧杂-戊二酰胺)在水/硝基苯界面推动H^+, Li^+, Na^+, Zn^2^+, Mg^2^+, Cu^2^+的离子转移,对推动离子转移过程的机理进行了探讨, 测定了相应离子的扩散系数和其配合物的稳定常数。     

钌(II)-联吡啶——α-羟基羧酸——Ce(IV)偶合化学发光反应机理研究

系统地研究了Ce(IV), H2SO4, Ru(bipy)3^2^+和5种α-羟基羧酸对Ce(IV)氧化钌(II)-联吡啶化学发光反应速率的影响。结果表明,在选定的试验条件下, 化学发光反应速率分别与Ce(IV),Ru(bipy)3^2^+, 5种α-羟基羧酸的浓度和1/[H2SO4]^2成正比, 据此提出了偶合化学发光反应机理, 推导得到的反应速率方程与实验结果吻合。     

四元尖晶石相Li——M——Mn——O(M=Ni,Cr,Mo,V)嵌入电极的研究

制备了用不同价态的几种金属阳离子(Ni2^+,Cr3^+,V5^+,Mo6^+)修饰的尖晶石LiMn~2O~4嵌入化合物作为锂二次电池的阴极材料,对Li/LiM~yMn~2~-~yO~4电池进行了电化学和X射线衍射研究.结果表明,其它离子的掺杂使标准尖晶石LiMn~2O~4电极对锂的反复脱嵌和嵌入有了更强的承受力,但在不同程度上降低了其初始容量.循环性能的提高归于掺杂的金属阳离子使尖晶石结构趋于更稳定.同时还讨论了修饰离子对尖晶石相在充放电时5V电压平台出现的影响。     

新型氮杂大环化合物的研究3: 取代不对称多齿氮 杂大环化合物的合成、表征 与配位性能

合成了四种以Nsp^2和Nsp^3为配位原子的取代不对称多齿氮杂大环化合物,制备了它们与不同金属离子的配合物,通过元素分析和光谱表征,研究了配体的结构与其配位性能的关系。以吡啶环为侧链功能基的配体L^1和L^2可根据其环大小选择性地识别Na^+或K^+离子,与过渡金属离子形成1:1型配合物,而与Hg^2^+,Cd^2^+等离子则形成1:2型配合物。大环配体L^3与Co^2^+和Na^+离子形成的双核配合物中两个冠醚环和一个Na^+离子形成夹心配位结构。L^5环中有两个配位中心,因而可同时与两个Ru^2^+离子配位。L^1和L^2均表现出对不同金属离子良好的液膜传输性能和传输选择性。     

利用荧光浓度指示剂fura-2研究稀土离子的跨膜行为

本文提出了利用fura-2测量细胞内游离稀土离子浓度的定量方法。实验结果表明, 在模拟细胞内离子组成的条件下, 稀土离子La^3^+和Y^3^+与fura-2形成1:1的配合物。其配合物的表观离解常数分别为161nmol.dm^-^3和404nmol.dm^-^3,pH7.05, 有未配对f电子的Nd^3^+, Ho^3^+, Sm^3^+, Dy^3^+,Ce^3^+, Yb^3^+等稀土离子对荧光起萃灭作用。此性质使我们能够定性鉴定它们是否进入了细胞。我们使用如上性质, 利用单细胞阳离子测试系统, 以小鼠骨髓瘤细胞为模式细胞, 研究了上游离稀土离子的跨膜行为及部分体内小分子对稀土离子跨膜行为的影响。实验结果支持游离稀土离子不能通过细胞膜的假设, 而且所研究的体内小分子在生理浓度下对稀土离子的跨膜也无明显作用。     

RuX^2+(X=O,H,N,C)分子离子的势能函数与稳定性

用密度泛函B3LYP方法对RuX^2+(X=O,H,N,C)分子离子进行了理认研究,结果表明：PuO^2+,PuH^2+,PuN^2+和PuC^2+分子离子能稳定存在,基态电子状态是X5^Σ^-(PuO^2+),X8^Σ^-(PuH^2+),X4^Σ^+(PuN^2+)和X9^Σ^-(PuC^2+),势能函数为Murrell-Sorbie热函数,并导出了相应的几何性质,力学性质和光谱数据。     

用氟钽酸根指示电位滴定钽的新方法

A new potentiometric titration method for the determination of tantalum in sulfuric acid and hydrofluoric acid media is described. EMF's were monitored with a double-junction reference electrode and a flurortantalate ion selective indicator electrode made in this laboratory previously. Five titrants have been evaluated for the precipitation titration. CPC, BDTAC and TPA yield the highest precision and largest potentiometric breaks, then rank CETAB and Hyamine 1622 in turn. CPC is considered to be the most satisfactory owing to the most sharp end-point break yielded when 10^-^4M of Ta is titrated with it. The concentration of H2SO4 suitable for the titration is 0.18 to 1.8M and that of HF is 0.23 to 1.7M. The method is suitable for Ta content in the range of 0.5 to 150 mg with a coefficient of variation of 0.15% (9 results) for 20 mg of Ta. HCl, H3PO4, tartaric acid and (NH4)2C2O4 as wellas a large amount of Fe^3^+, Ni^2^+, Cr^3^+, WO2^-^4, Zr^4^+, La^3^+, Al^3^+, MoO2^-^4 and Nb^5^+ do not interfere, while ClO^-^4, H2O2 and BF^-^4 must be avoided. The method has been found to be very useful for the determination of Ta in steels and crystalline lithium tantalate. The results obtained are in good agreement with those of comparable methods. This method is very simple and provides a fast determination process.     

TiP2^+,TiP4^+,Ti2P4^+二元团簇的理论研究

利用含有电子相关效应校正的密度泛函理论DFT中的B3LYP方法,选择LANL2DZ双ξ基组,并考虑极化函数,对TiP2^+,TiP4^+,Ti2P4^+二元团簇各种可能存在的几何构型及电子结构进行了密度泛函理论研究,得到了TimPn^+二元团族的最稳定构型,其中TiP2^+的最稳定构型为C2v对称性的三角形,TiP4^+的最稳定构型亦具有C2v对称性,Ti2P4^+的最稳定构型为具有D2d对称性的共边双四面体,所得构型很好地说明了激光光解的实验结果。     

Sorption Properties of Bulk and Deposited Ammonium Molibdophosphate with Respect to Cs+, Sr2+, and UO 2 2 + $$ {\mathrm{UO}}_2^{2+} $$ Ions

Theoretical and Experimental Chemistry - The sorption of Cs+, Sr2+, and $$ {\mathrm{UO}}_2^{2+} $$ ions on bulk ammonium molibdophosphate (AMP) and also on compositions obtained by its deposition...     

Dioxadiaza- and trioxadiaza-macrocycles containing one dibenzofuran unit selective for cadmium

The binding properties of dioxadiaza- ([17](DBF)N2O2) and trioxadiaza- ([22](DBF)N2O3), macrocyclic ligands containing a rigid dibenzofuran group (DBF), to metal cations and structural studies of their metal complexes have been carried out. The protonation constants of these two ligands and the stability constants of their complexes with Ca2+, Ba2+, and Mn2+, Co2+, Ni2+, Cu2+, Zn2+ and Cd2+, were determined at 298.2 K in methanol-water (1:1, v/v), and at ionic strength 0.10 mol dm-3 in KNO3. The values of the protonation constants of both ligands are similar, indicating that no cavity size effect is observed. Only mononuclear complexes of these ligands with the divalent metal ions studied were found, and their stability constants are lower than expected, especially for the complexes of the macrocycle with smaller cavity size. However, the Cd2+ complex with [17](DBF)N2O2 exhibits the highest value of stability constant for the whole series of metal ions studied, indicating that this ligand reveals a remarkable selectivity for cadmium(II) in the presence of all the metal ions studied, except copper(II), indicating that this ligand reveals a remarkable selectivity for cadmium(II) in the presence of the mentioned metal ions. The crystal structures of H2[17](DBF)N2O3(2+) (diprotonated form of the ligand) and of its cadmium complex were determined by X-ray diffraction. The Cd2+ ion fits exactly inside the macrocyclic cavity exhibiting coordination number eight by coordination to all the donor atoms of the ligand, and additionally to two oxygen atoms from one nitrate anion and one oxygen atom from a water molecule. The nickel(II) and copper(II) complexes with the two ligands were further studied by UV-vis-NIR and the copper(II) complexes also by EPR spectroscopic techniques in solution indicating square-pyramidal structures and suggesting that only one nitrogen and oxygen donors of the ligands are bound to the metal. However an additional weak interaction of the second nitrogen cannot be ruled out.     

溶液中N-乙酸基取代氮氧杂大环及其配合物稳定性研究

用pH电位滴定法在25℃,0.5mol·L~(-1)KNO_3水溶液中测定了三种大环化合物:H_2L~1(1,12-二氮杂-3,4:9,10-二苯并-5,8-二氧杂环十五烷-N,N＇-二乙酸);H_3L~2(1,12,15-三氮杂-3,4:9,10-二苯并-5,8-二氧杂环十七烷-N,N＇,N″-三乙酸)和H_2L~3(1,15-二氮杂-3,4:12,13-二苯并-5,8,11-三氧杂环十八烷-N,N′-二乙酸)的逐级质子化常数.又测定了它们与Cu~(2+)、Ni~(2+)、Pb~(2+)配合物的稳定常数,以及H_2L~3与镧系金属La~(3+)、Pr~(3+)、Nd~(3+)、Eu~(3+)、Sm~(3+)、Gd~(3+)、Dy~(3+)、Yb~(3+)配合物的稳定常数.讨论了三种大环化合物质子化的一般顺序及其与各种离子配位时稳定性选择规律.说明了影响配位稳定性的有关因素.     

Complexation of Metal Ions with Azacrown Ethers Bearing an 8-Hydroxyquinoline Side Arm

Thermodynamic quantities (log, K, H, and TS) for theinteractions of six azacrown ethers each bearing an 8-hydroxyquinoline (CHQ)side arm (1-6) with Na+, K+, Ba2+, and Cu2+ were determined by calorimetrictitration in methanol solution at 25°C. The results indicate that theseligands form stable complexes with the cations studied. Ligands 1 and 3 thathave CHQ attached through position 7 (next to the OH group) show highselectivity for Cu2+ (log K values of 8.12 and 9.44, respectively) over Na+,K+, and Ba2+ by more than four orders of magnitude. On the other hand,ligands 2 and 4 that have CHQ attached through position 2 (next to thequinoline nitrogen group) form more stable complexes with Na+, K+, and Ba2+,but less stable complexes with Cu2+, than ligands 1 and 3. All ligandsinteract more strongly with K+ than with Na+. The K+/Na+ selectivity forligands 4 and 5 is about 1.5 log K units. All complexation reactions displaynegative enthalpy changes. In most cases the entropy changes are alsonegative, indicating that formation of the complexes is enthalpy driven. 1HNMR spectral experiments demonstrate coordination of the cations by alldonor atoms of the ligands including those of the CHQ arm. In all cases, theOH signal is observed in the 1H NMR spectra, suggesting that thecomplexation with the cations does not involve deprotonation of the CHQgroups in the ligands.