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91.
《Journal of Coordination Chemistry》2012,65(1-4):17-22
Abstract We report a new crystal structure of the title clathrate containing tetrahedral and octahedral Cd atoms in a ratio of 1:1. The preparation of the compound is similar to that of the cristobalite-like clathrate Cd(CN)2·G, where all Cd atoms are tetrahedral. The new inclusion compound crystallizes in the monoclinic space group C2/c, a = 12.337(4), b = 11.964(3), c = 13.594(3) Å, β = 108.60(2)°, Z = 4, R = 0.034 for 1631 reflections. The three-dimensional host framework is built of alternate linkages between the tetrahedral Cd atom of the tetracyanocadmate and the octahedral Cd atom similar to that of the Hofmann-Td and the en-Td types. In the new clathrate dual behavior of acetonitrile, one as a unidentate ligand in the three-dimensional host framework and the other as the guest in the cage-like cavity, has been demonstrated. 相似文献
92.
93.
Two couples of enantiomerically pure chiral cyano-bridged heterobimetallic one-dimensional (1D) chain complexes: [Mn((R,R)-Salphen)Fe(Tp)(CN)3]n (1) and [Mn((S,S)-Salphen)Te(Tp)(CN)3]n (2) (Salphen = N,N’-1,2-diphenylethylenebis (salicylideneiminato) dianion, Tp = tris(pyrazolyl) hydroborate), [Mn((R,R)-Salphen)Fe(Tp*)(CN)3·2H2O]n (3) and [Mn((S,S)-Salphen)Fe(Tp*)(CN)3·2H2O]n (4) (Tp* = hydridotris (3,5-dimethylpyrazol-1-yl) borate), have been successfully synthesized by the reactions of MnIII schiff-base complexes with the tricyanometalate building block, [(LTp)Fe(CN)3]- (LTp = Tp or Tp*). All complexes are made up of neutral cyano-bridged zigzag double chains with (-Fe-C≡N-Mn-N≡C-)n as the repeating unit. Circular dichroism (CD) spectra confirm the enantiomeric nature of the optically active complexes. Magnetic studies demonstrate that ferromagnetic interactions are operative in these complexes. The ferromagnetic couplings become weak in the chains with the bending of the Mn-N≡C angles. 相似文献
94.
提出了一种计算方法,定量地计算了沉淀和络合化学反应体系中的金属阳离子和阴离子的分布,考察了影响沉淀和络合物形成的各种因素。基于提出的公式,计算了金、银、铜、镍阳离子和氰根阴离子的沉淀率,理论计算与实验结果一致。 相似文献
95.
在传统氰化物检测方法的基础上,提出了一种新的方法—数码比色法。在一定条件下,苦味酸与氰化物生成黄色化合物,用数码相机对显色溶液拍照,通过数码比色,进行灰度处理,照片的三原色值与氰化物的浓度成线性关系,可以直接分析出其氰化物的浓度。对唾液样品测定,其回收率为98.18%,对照品测定的相对标准偏差RSD为1.5%。研究结果表明,数码比色法具有准确度和精密度都比较理想,方便快速、环境友好等特点。 相似文献
96.
《Analytical letters》2012,45(9):2075-2082
Abstract A spectrophotometric method for nickel has been developed based on the formation of a ternary complex in the system Ni(II)/3-(4′,5′-dimethyl-2′-thiazolylazo)-2,6-dihydroxybenzoic acid/cyanide at pH 9.2 (borate buffer), which allows the determination of 0.05–0.47ppm of nickel (ε = 3.53×104 1.mol?1. cm?1) at 538nm. Interferences have been studied and the method applied to the determination of nickel in low alloy steels. 相似文献
97.
《Analytical letters》2012,45(2):319-330
Abstract A rapid procedure has been developed for the analysis of orthophosphate, sulfate and chloride in riverine sediment interstitial water samples which have dissolved iron concentrations ranging from 0.5–2 mmol L?1. Interferences caused by the precipitation of iron hydroxides resulting from air oxidation of ferrous iron in the anoxic samples and from the alkaline working pH range (9.0 – 10.5) of the Dionex1 ion chromatographic system were eliminated by complexing the iron with cyanide. Orthophosphate concentration values are compared with dissolved reactive phosphate concentration data for the same samples. Orthophosphate concentrations rather than dissolved reactive phosphate concentrations are preferred for phosphate mineral solubility calculations and for phosphorus nutrient measurements. 相似文献
98.
《Analytical letters》2012,45(14):2797-2803
Abstract A rapid, simple and sensitive fluorimetric method has been developed for the determination of cyanide with fluorescein as fluorogenic reagent (λex = 494 nm, λem = 514 nm) at pH 6.0–7.0. A linear calibration curve was obtained in the range 0.004–2.0 μg CN?/25 ml. The detection limit is 0.004 μg CN-/25 ml. The method was successfully applied to the determination of cyanide in waste water. 相似文献
99.
100.
研究了双金属氰化配合物(DMC)催化剂催化二氧化碳(CO2)与环氧丙烷(PO)的共聚及PO的均聚反应,考察了DMC催化剂的诱导现象。结果表明,共聚时DMC催化的诱导期比均聚短,尤其是在低CO2压力(1.0MPa)下更明显,诱导期由均聚时的45min缩短为共聚时的15min。共聚时诱导期随CO2压力升高而增加,当反应压力由1.0MPa升高至7.0MPa时,诱导期由15min增至40min。PO与CO2共聚时的引发现象不同于PO均聚:共聚引发时温度和压力突然异常升高并迅速降低至引发前的状态,而均聚引发时温度突然升高后逐渐下降。由此可知CO2能促进DMC催化剂的活化。 相似文献