3,5-diCl-DMPAP光度法同时测定铜和锌

研究了在乳化剂OP存在下,以2 (3,5 二氯 2 吡啶偶氮) 5 二甲氨基酚(3,5 diCl DMPAP)为显色剂使铜和锌同时显色,再以硫脲 硫代硫酸钠掩蔽铜,利用两次所测吸光度之差以差减法同时测定铜、锌。试验结果表明,pH6.0～10.0时,铜和锌与试剂均形成1∶2的紫红色配合物。铜配合物的最大吸收波长位于558nm处,锌配合物的最大吸收波长位于565nm处。两者在562nm波长处的吸光度具有良好加和性,其表观摩尔吸光系数分别为εCu=9.6×104L·mol-1·cm-1,εZn=1.2×105L·mol-1·cm-1。方法灵敏度高、操作简单,用于地质化探样品和人发中微量铜、锌的同时测定,结果满意。     

新显色剂1-羟基-2-(5-NO2-2-吡啶偶氮)-8-氨基-3,6-萘二磺酸与铜显色反应的研究

探讨了新显色剂 1-羟基-2-(5-NO2-2-吡啶偶氮)-8-氨基-3,6-萘二磺酸(简称5-NO2-PAH)与铜离子显色的适宜条件及其共存离子的影响,建立了 5-NO2-PAH测定铜的新显色反应体系.在 pH 7.0～10.0 范围内,铜与试剂形成稳定的 1∶2 配合物,其最大吸收峰位于 653 nm, 表观摩尔吸光系数εCu=4.68×104 L·mol-1·cm-1,铜的浓度在 0 μg/10 mL～14 μg/10 mL 范围内遵守比尔定律.方法已用于合金中铜的测定.     

镧-曲利本红光度法测定新霉素及庆大霉素

在pH3.0～6.5的条件下,镧(Ⅲ) 曲利本红(TR)与硫酸新霉素(NEO)或硫酸庆大霉素(GEN)反应生成三元红色离子缔合物,其最大吸收波长位于388nm,摩尔吸收光系数(ε)为4.86×104、2.10×104L·mol-1·cm-1;最大负吸收波长位于432nm(NEO)和428nm(GEN),摩尔吸收光系数(ε)为1.38×104、1.19×104L·mol-1·cm-1。当用双波长叠加时,ε值为6.24×104(NEO)、3.28×104(GEN)L·mol-1·cm-1。探讨了适宜的反应条件和主要分析化学性质。该法用于市售药物中新霉素、庆大霉素含量的测定,结果满意。     

1-(4-硝基苯)-3-(3-甲基吡啶)-三氮烯合成及其与铜的显色反应

报道了新显色剂 1-(4-硝基苯)-3-(3-甲基吡啶)-三氮烯(NPMPDT)的合成及其与铜的显色反应.在OP的存在下,pH 10.5的Na2B4O7-NaOH缓冲溶液中,该试剂能与铜发生显色反应,铜与NPMPDT形成摩尔比为2∶1型的黄色配合物,在460 nm处有一最大正吸收,在535 nm 处有一最大负吸收.以460 nm为参比波长,535 nm为测量波长进行双波长测定,其表观摩尔吸光系数ε＝2.18×105 L·mol-1·cm-1,铜的质量浓度在0～0.48 μg/mL 范围内符合比尔定律,用本法测定大米和面粉中微量的铜,结果满意.     

新试剂1-(4-安替比林偶氮)-4-氨基-2-萘甲酸与铜显色反应研究

在pH60HAc－NH4Ac缓冲介质中,CTMAB存在下,1－（4-安替比林偶氮）－4氨基一2一萘甲酸（AANA）与铜生成2：1红色络合物,λmax＝540nm,ε=4.06×104L·Lmol-1·cm-1,铜含量在0－30μg/25内符合比尔定律,方法用于食品中铜的测定,结果满意。     

4-(6-甲氧基-8-喹啉偶氮)-间苯二酚与Ni(Ⅱ)的显色反应

研究了4-(6-甲氧基-8-喹啉偶氮)-间苯二酚(MQAR)与Ni(Ⅱ)的显色反应。确立了Ni(Ⅱ)与MQAR显色反应的条件,配合物的最大吸收波长为570nm,对比度为98nm,镍含量在0.2-1.6mg·L-1范围内服从比耳定律,表观摩尔吸光系数为2.63×104L·mol-1·cm-1,表观稳定常数为1.26×10(10),Sandell灵敏度为2.17×10-3μg·cm-2。用于人发和血清中镍的测定,取得了满意的结果。     

2-(2-喹啉偶氮)-1,5-苯二酚光度法测定银的研究

研究了2 (2 喹啉偶氮) 1,5 苯二酚(QADHB)试剂与银的显色反应,在pH 5.0的柠檬酸氢氧化钠缓冲(内含0. 01 mol·L-1 的Na2EDTA)介质中,十二烷基磺酸钠(SDS)存在下,QADHB与银反应生成2∶1 稳定的络合物,λmax=550 nm,ε=6.56×104L·mol-1·cm-1。银含量在0~30μg/25 mL内符合比耳定律,方法用于环境水样中银含量的测定,结果满意。     

5-Br-PADN光度法连续测定铸铁中铜和镍

研究了以溴代十六烷基吡啶和TritonX 100为增溶剂,以5 Br PADN为显色剂,在pH为9.7的氨 氯化铵介质下连续测定铜和镍的方法。铜、镍与5 Br PADN的配合物在547nm处均有较大的吸收,其表观摩尔吸光系数为εCu=3.94×104L·mol-1·cm-1,εNi=3.64×104L·mol-1·cm-1,配合物至少可稳定12h,铜、镍分别在0～10μg/10ml和0～8μg/10ml范围内服从比耳定律,方法用于铸铁中铜和镍的连续测定,结果满意。     

2-(3-羧基-2,4,5-三氮唑偶氮)-5-乙酰氨基苯酚与铜(Ⅱ)的显色反应及应用

介绍了新显色剂2 (3 羧基 2,4,5 三氮唑偶氮) 5 乙酰氨基苯酚(CTZAAP)与铜的显色反应研究及应用,建立了测定铜的新方法。在pH5.5的HOAc NaOAc缓冲溶液中,该试剂与铜(Ⅱ)形成1∶1红色稳定络合物,λmax为561.2nm,铜(Ⅱ)量在0～1.0μg·ml-1范围内符合比耳定律,表观摩尔吸光系数为2.16×104L·mol-1·cm-1。其他金属离子共存时,不经预分离可直接测定食品及环境水样中的微量铜(Ⅱ),操作简便,结果满意。     

5-(5-硝基-2-吡啶偶氮)-2,4-二氨基甲苯吸光光度法同时测定铜和钯

提出用5 (5 硝基 2 吡啶偶氮) 2,4 二氨基甲苯(5 NO2 PADAT)光度法同时测定铜和钯的新体系。室温下,铜与试剂仅能在pH4.5～6.0范围内定量反应,而钯与试剂于强酸性介质中即可显色完全。基于铜配合物可被EDTA分解而钯配合物不被分解,及铜、钯配合物形成的酸度差异,实现了铜、钯的同时测定。铜浓度在0～0.7μg·ml-1、钯浓度在0～0.9μg·ml-1范围内符合比耳定律,其表观摩尔吸光系数分别为ε519Cu=6.70×104L·mol-1·cm-1,ε592Pd=1.25×105L·mol-1·cm-1。方法已成功用于矿样和电镀活化废液中铜、钯的同时测定。     

OH(3) (-) and O(2)H(5) (-) double Rydberg anions: predictions and comparisons with NH(4) (-) and N(2)H(7) (-)

A low barrier in the reaction pathway between the double Rydberg isomer of OH(3) (-) and a hydride-water complex indicates that the former species is more difficult to isolate and characterize through anion photoelectron spectroscopy than the well known double Rydberg anion (DRA), tetrahedral NH(4) (-). Electron propagator calculations of vertical electron detachment energies (VEDEs) and isosurface plots of the electron localization function disclose that the transition state's electronic structure more closely resembles that of the DRA than that of the hydride-water complex. Possible stabilization of the OH(3) (-) DRA through hydrogen bonding or ion-dipole interactions is examined through calculations on O(2)H(5) (-) species. Three O(2)H(5) (-) minima with H(-)(H(2)O)(2), hydrogen-bridged, and DRA-molecule structures resemble previously discovered N(2)H(7) (-) species and have well separated VEDEs that may be observable in anion photoelectron spectra.     

Mixed ligand titanium(IV) complexes. Chlorobis(dithiocarbamato)bis(methylsalicylato)titanium(IV) andbis(dithiocarbamato)bis(methylsalicylato)titanium(IV)

Summary Dichlorobis(methylsalicylato)titanium(IV) reacts with potassium or amine salts of dialkyl or diaryl dithiocarbamates in 11 and 12 molar ratios in anhydrous benzene (room temperature) or in boiling CH₂Cl₂ to yield mixed ligand complexes: (AcOC₆H₄O)₂ Ti(S₂CNR₂)Cl (1) and (AcOC₆H₄O)₂ Ti(S₂CNR₂)₂ (2), R=Et, n-Pr, n-Bu, cyclo-C₄H₈ and cyclo-C₅H₁₀. These compounds are moisture sensitive and highly soluble in polar solvents. Molecular weight measurement in conjunction with i.r.,¹H and¹³C n.m.r. spectral studies suggest coordination number 7 and 8 around titanium(IV) in (1) and (2) respectively.     

Bis(trifluoroacetyl) peroxide, CF(3)C(O)OOC(O)CF(3)

Pure, highly explosive CF(3)C(O)OOC(O)CF(3) is prepared for the first time by low-temperature reaction between CF(3)C(O)Cl and Na(2)O(2). At room temperature CF(3)C(O)OOC(O)CF(3) is stable for days in the liquid or gaseous state. The melting point is -37.5 degrees C, and the boiling point is extrapolated to 44 degrees C from the vapor pressure curve log p = -1875/T + 8.92 (p/mbar, T/K). Above room temperature the first-order unimolecular decay into C(2)F(6) + CO(2) occurs with an activation energy of 129 kJ mol(-1). CF(3)C(O)OOC(O)CF(3) is a clean source for CF(3) radicals as demonstrated by matrix-isolation experiments. The pure compound is characterized by NMR, vibrational, and UV spectroscopy. The geometric structure is determined by gas electron diffraction and quantum chemical calculations (HF, B3PW91, B3LYP, and MP2 with 6-31G basis sets). The molecule possesses syn-syn conformation (both C=O bonds synperiplanar to the O-O bond) with O-O = 1.426(10) A and dihedral angle phi(C-O-O-C) = 86.5(32) degrees. The density functional calculations reproduce the experimental structure very well.