Tb(Ⅲ)-EDTP-吡啶-2-甲酸三元体系的溶液荧光

Ｔｂ－乙二胺四亚甲基磷酸－吡啶－２－甲酸三元体系的溶液荧光呈典型的Ｔｂ（Ⅲ）离子的特征荧光,而激发峰位于３１０ｎｍ,为吡啶－２－甲酸的吸光区域,表明在溶液中形成了Ｔｂ－乙二胺四亚甲基膦酸－吡啶－２－甲酸三元配合物。该三元配合物的荧光在ｐＨ为６．０时最强,同时随吡啶－２－甲酸含量的增加而增加,但过量的乙二胺四亚甲基膦酸的加入不影响体系的荧光。     

非离子型微乳液对导数分光光度法测定微量铁的增敏作用

与胶束介质比较,非离子型Ｏ／Ｗ微乳液Ｔｒｉｔｏｎ Ｘ－１００／ｎ－Ｃ５Ｈ１１ＯＨ／ｎ－Ｃ９Ｈ２０／Ｈ２Ｏ对以磺基水杨酸为显色剂三阶导数分光光度法测定微量铁有更好的增敏作用。在ｐＨ４－６的六次甲基四胺－盐酸介质中,铁－磺基水杨酸配合物的最大吸收工λｍａｘ为２４９ｎｍ,微乳液介质中的测定灵敏度比胶束介质中提高近一倍。     

多核芳烃正离子自由基的ENDOR和EPR研究

用ＥＰＲ和ＥＮＤＯＲ方法检测傅氏烷基化反应（Ｆｒｉｅｄｅｌ－Ｃｒｕｆｔｓｒｅａｃｔｉｏｎ）中所生成的多核芳烃正离子自由基：１，４，５，８－四甲基惠、９，１０－二氘代－１，４，５，８－四甲基蒽、２，６，９，１０－四甲基蒽、２，６－二甲基－９，１０－二（对甲苯基）蒽、３，６，１１，１４－四甲基二苯并（ａ，ｃ）三亚苯正离子自由基，测定了它们的超精细偶合常数并提出了其生成机理。     

一种新型尾式卟啉吡啶季铵盐对锌离子显色反应的研究

本文研究了一种新型尾式卟啉吡啶季铵盐５－「４－（４－吡啶丁氧基）苯基」－１０,１５,２０－三（４－氯苯基）卟啉溴化物与锌的反应条件。ＰＨ＝１０．０,在吡啶存在下于沸水浴中加热１５ｍｉｎ,其与Ｚｎ＾２＋形成１：１配合物,其最大吸收波长位于４２８．６ｎｍ,在此条件下试剂的最大吸收波长在４１８．２ｎｍ,相差１０ｎｍ,配合物摩尔吸光系数４．６４×１０＾５Ｌ·ｍｏｌ·ｃｍ＾－１,锌在０－１．２μｇ／１０ｍＬ     

2，4，6－三芳基－N－取代吡啶盐的~（13）CNMR研究

用￣（１３）Ｃ－￣１ＨＣＯＳＹ、２Ｄ－Ｊ分解谱并结合选择性质子去偶以及ＤＥＰＴ技术对２５个新的２，４，６－三芳基－Ｎ－取代吡啶四氟硼酸盐的￣（１３）ＣＮＭＲ谱进行了归属，讨论了影响化学位移的因素。     

邻啡啰啉─吡啶2，6二甲酸铕二、三元配合物的NMR研究

报道了稀上铕（Ｅｕ３＋）与吡啶－２，６－二甲酸（Ｈ２ＤＰＣ）及邻啡啉（Ｐｈｅｎ）形成的二元和三元固体配合物的制备．对它们进行了元素分析，确定该配合物的组成为二元Ｎａ３［Ｅｕ（ＤＰＣ）３］２Ｈ２Ｏ和三元ＮａＥｕ（ＤＰＣ）２·４Ｈ２Ｏ，对上述配合物的结构作了核磁共振氢谱（１ＨＮＭＲ）、碳谱（１３ＣＮＭＲ）和氮谱（１４ＮＮＭＲ）及红外光谱（ＩＲ）的研究．吡啶－２，６－二甲酸中的羧基以单齿配位（整个分子为三齿配位）．二、三元配合物中铕的配位数分别为９和８．     

一种新尾式卟啉吡啶季铵盐对锌离子显色反应的研究

本文研究了一种新型尾式卟啉吡啶季铵盐５－［４－（４－吡啶丁氧基）苯基］－１０,１５,２０－三（４－氯苯基）卟啉溴化物与锌的反应条件。ｐＨ＝１０．０,在吡啶存在下,于沸水浴中加热１５ｍｉｎ,其与Ｚｎ２＋形成１∶１配合物,其最大吸收波长位于４２８．６ｎｍ,在此条件下试剂的最大吸收波长在４１８．２ｎｍ,相差１０ｎｍ,配合物摩尔吸光系数４．６４×１０５Ｌ·ｍｏｌ－１·ｃｍ－１,锌在０—１．２μｇ／１０ｍＬ范围内符合比耳定律,相关系数ｒ＝０．９８８８,本法是目前报道的分光光度法测定锌的最灵敏方法之一。     

新试剂N—壬基—N‘—（氨基对苯磺酸钠）硫脲（NPT）与钯（Ⅱ）显色？…

研究新合成的水溶性光度试剂Ｎ－壬基－Ｎ‘－（氨基对苯磺酸钠）硫脲与钯的显色反应。结果表明，在ｐＨ５．８－６．６的ＨＡｃ－ＮａＡｃ缓冲体系中，Ｐｄ＾２＋与ＮＴＰ形成１：４的黄色水溶性配合后物，ＣＴＭＡＢ对反应有明显的增敏作用，配合物的最大吸收波长位于２９７．６ｎｍ，表面摩尔吸光系数ε２９７．６＝１．２７×１０＾５Ｌ．ｍｏｌ＾－１ｃｍ＾－１，钯含量在２－１１．２μｇ／２５ｍＬ范围内服从比尔定律，５０种     

苯并三氮唑对铜和铁缓蚀作用的拉曼光谱研究

本文利用现场拉曼光谱研究了中性含氯离子溶液中苯并三氮唑在铜和铁电极表面的吸附以及成膜行为,结果表明苯并三氮唑能强烈地化学吸附于铜电极和铁电极表面,形成类似［Ｍｎ（ＢＴＡ）ｐ］的配合物膜,一定程度上阻止了膜内外物质的交换,对金属起缓蚀作用。另一方面两种金属表面配合物膜均具有电位依赖性：在铜电极表面,当外加电位由－０．５Ｖ负移至－０．９Ｖ时,发生了由［Ｃｕ（Ⅰ）（ＢＴＡ）］ｎ向［Ｃｕ（Ⅰ）Ｃｌ（ＢＴＡＨ）］４的转变;而在铁电极表面当外加电位由－０．６Ｖ负移至－１．２Ｖ时,最初形成的表面配合物［Ｆｅｎ（ＢＴＡ）ｐ］则很可能转变成类似于［Ｆｅｎ（Ｃｌ）ｐ（ＢＴＡＨ）ｍ］的配合物,从而使得ＢＴＡＨ对铜、铁的缓蚀能力均有所下降。     

析相光度法测定铁(Ⅲ)的研究

本研究了铁（Ⅲ）－ＰＥＧ（聚乙二醇－２０００）－铬锖Ｒ－Ｎａ２ＳＯ４体系的上光度法并应用于测定Ｆｅ（Ⅲ）。最适酸并为４．５￣６．５（ＮａＡｃ－ＨＡｃ）缓冲溶液,其络合物的最大吸收位于５６０ｎｍ,表观摩尔吸光系数为５．３６×１０＾４Ｌ·ｍｏｌ＾－１·ｃｍ＾－１,Ｆｅ（Ⅲ）浓度在０￣４μｇ范围内服从比尔定律,铁与铬菁Ｒ形成组成为１：２的稳定络合物。该方法用于蔡叶中铁的测定,获得了满意的结果。     

Fabrication and characterization of SERS‐active silver clusters on glassy carbon

In this article, a novel technique for the fabrication of surface enhanced Raman scattering (SERS) active silver clusters on glassy carbon (GC) has been proposed. It was found that silver clusters could be formed on a layer of positively charged poly(diallyldimethylammonium) (PDDA) anchored to a carbon surface by 4‐aminobenzoic acid when a drop containing silver nanoparticles was deposited on it. The characteristics of the obtained silver clusters have been investigated by atomic force microscopy (AFM), SERS and an SERS‐based Raman mapping technique in the form of line scanning. The AFM image shows that the silver clusters consist of several silver nanoparticles and the size of the clusters is in the range 80–100 nm. The SERS spectra of different concentrations of rhodamine 6G (R6G) on the silver clusters were obtained and compared with those from a silver colloid. The apparent enhancement factor (AEF) was estimated to be as large as 3.1 × 10⁴ relative to silver colloid, which might have resulted from the presence of ‘hot‐spots’ at the silver clusters, providing a highly localized electromagnetic field for the large enhancement of the SERS spectra of R6G. The minimum electromagnetic enhancement factor (EEF) is estimated to be 5.4 × 10⁷ by comparison with the SERS spectra of R6G on the silver clusters and on the bare GC surface. SERS‐based Raman mapping technique in the form of line scanning further illustrates the good SERS activity and reproducibility on the silver clusters. Finally, 4‐mercaptopyridine (4‐Mpy) was chosen as an analyte and the lowest detected concentration was investigated by the SERS‐active silver clusters. A concentration of 1.6 × 10⁻¹⁰ M 4‐Mpy could be detected with the SERS‐active silver clusters, showing the great potential of the technique in practical applications of microanalysis with high sensitivity. Copyright © 2006 John Wiley & Sons, Ltd.     

Effect of surface morphology on surface‐enhanced Raman scattering of 4‐aminobenzenethiol adsorbed on gold substrates

The substrate‐dependent surface‐enhanced Raman scattering (SERS) of 4‐aminobenzenethiol (4‐ABT) adsorbed on Au surfaces has been investigated. 4‐ABT is one of the very unique adsorbate molecules whose SERS spectral patterns are known to be noticeably dependent on the relative contribution of chemical enhancement mechanism vs electromagnetic enhancement mechanism. The SERS spectral patterns of 4‐ABT adsorbed on gold substrates with various surface morphology have thus been analyzed in terms of the symmetry types of the vibrational modes. Almost invisibly weak b₂ type vibrational bands were observed in the SERS spectra of the 4‐ABT adsorbed on Au colloidal sol nanoparticles or commercially available Au micro‐powders because of the weak contribution of the chemical enhancement. However, greatly enhanced b₂ vibrational bands were observed in the spectra of the 4‐ABT molecules adsorbed on the synthesized Au(Zn) sponge or the electrochemically roughened Au(ORC) foil caused by the strong contribution of the chemical enhancement mechanism. Copyright © 2008 John Wiley & Sons, Ltd.     

3.4% NaCl介质中铁点蚀行为的表面拉曼光谱成像研究

本文利用共焦拉曼光谱技术结合对铁电极的合适的粗糙化预处理,现场研究了３．４％ＮａＣｌ腐蚀介质听电极的点蚀行为,获得了点蚀坑内腐蚀产物的表面增强拉曼光谱,成功地将表面增强拉曼光谱技术拓宽至铁的腐蚀行为的研究中,利用共焦拉曼光谱仪的成像技术研究了位于６６０ｃｍ＾－１处点蚀产物的二维分布图。研究表明：在校正电位铁表面发生点蚀后,点蚀坑内腐蚀产物不是以单一物种存在,而是多种铁氧化合物共存,且这些铁的氧化腐蚀产物的点蚀坑内的分布也极不均匀。     

Theoretical elucidation of the origin of surface‐enhanced Raman spectra of PCB52 adsorbed on silver substrates

To better understand experimentally observed surface‐enhanced Raman Scattering (SERS) of polychlorinated biphenyls (PCBs) adsorbed on nanoscaled silver substrates, a systematic theoretical study was performed by carrying out density functional theory and time‐dependent density functional theory calculations. 2,2′,5,5′‐tetrachlorobiphenyl (PCB52) was chosen as a model molecule of PCBs, and Ag_n (n = 2, 4, 6, and 10) clusters were used to mimic active sites of substrates. Calculated normal Raman spectra of PCB52–Ag_n (n = 2, 4, 6, and 10) complexes are analogical in profile to that of isolated PCB52 with only slightly enhanced intensity. In contrast, the corresponding SERS spectra calculated at adopted incident light are strongly enhanced, and the calculated enhancement factors are 10⁴ ~ 10⁵. Thus, the experimentally observed SERS phenomenon of PCBs supported on Ag substrates should correspond to the SERS spectra rather than the normal Raman spectra. The dominant enhancement in Raman intensities origins from the charge transfer resonance enhancement between the molecule and clusters. Copyright © 2014 John Wiley & Sons, Ltd.     

Visible light response of silver 4‐aminobenzenethiolate and silver 4‐dimethylaminobenzenethiolate probed by Raman scattering spectroscopy

Silver thiolate is a layered compound with a Raman spectrum that is known to change with time, becoming the same as the surface‐enhanced Raman scattering (SERS) spectrum of the parent thiol molecule adsorbed on Ag nanoparticles. On this basis, the Raman scattering characteristics of silver 4‐aminobenzenethiolate (Ag‐4ABT) compounds were investigated to determine whether certain peaks that are identifiable in the SERS spectrum of 4‐aminobenzenethiol (4‐ABT) but absent in its normal Raman spectrum were also apparent in the Ag salt spectrum. For comparative purposes, the Raman scattering characteristics of silver 4‐dimethylaminobenzenethiolate (Ag‐4MABT) were also examined. Raman spectra acquired while spinning the sample were typified by only a₁‐type vibrational bands of Ag‐4ABT and Ag‐4MABT, whereas in the static condition, several non‐a₁‐type bands were identified. The spectral patterns acquired in the static condition were similar to the intrinsic SERS spectra of 4‐ABT or 4‐dimethylaminobenzenethiol (4‐MABT) adsorbed on pure Ag nanoparticles. Notably, the CH₃ group vibrational bands were observable for Ag‐4MABT irrespective of the sample rotation. In addition, no decrease in intensity during irradiation with a visible laser was observed for any of the bands, suggesting that no chemical conversion actually took place in either 4‐ABT or 4‐MABT. The preponderance of evidence led to the conclusion that the non‐a₁‐type bands observable in the SERS spectra must be associated with the chemical enhancement mechanism acting on the Ag nanoparticles. The chemical enhancement effect was more profound at 514.5 nm than at 632.8 nm, and was more favorable for 4‐ABT than 4‐MABT at both wavelengths. Copyright © 2012 John Wiley & Sons, Ltd.     

Proline and hydroxyproline deposited on silver nanoparticles. A Raman,SERS and theoretical study

The Raman and surface‐enhanced Raman scattering (SERS) spectra of l ‐proline (Pro) and trans‐4‐hydroxy‐ l ‐proline (Hyp) were recorded. SERS spectra were obtained on colloidal Ag prepared by reduction with hydroxylamine. Allowing sufficient time for Pro and Hyp to adjust in the colloidal solution resulted fundamentally in obtaining unique and reproducible SERS spectra. Hyp stabilizes on the surface more rapidly than Pro. The spectral analysis indicates that Pro interacts with the Ag surface through the carboxylate group. The interaction of Hyp with the metal surface occurs through the amino, methylene and carboxylate moieties of the molecule. The spectroscopic results are supported by quantum chemical calculations, performed using extended Hückel theory (EHT) of the title compounds interacting with an Ag cluster model. The assignment of the Raman bands was supported by a normal coordinate analysis performed through Becke, three‐parameter, Lee–Yang–Parr/6‐311 G* + calculations. Copyright © 2011 John Wiley & Sons, Ltd.     

Surface‐enhanced Raman scattering of 4‐aminobenzenethiol on silver: confirmation of the origin of b2‐type bands

In order to resolve the dispute on the origin of the b₂‐type bands in the surface‐enhanced Raman scattering (SERS) of 4‐aminobenzenethiol (4‐ABT), we have measured its SERS spectra under a variety of conditions, including variable temperature and rotation, electrochemistry, and pH, as well as in the presence of a reducing agent. For comparison, the SERS spectra of 4‐nitrobenzenethiol (4‐NBT) and methyl orange (MO), a prototype azo compound, were also measured. First, we found that 4‐ABT on Ag is not subjected to photoreaction, although 4‐NBT is highly photoreactive on a silver surface. In the electrochemical environment, b₂‐type bands of 4‐ABT lost their intensity at very negative potentials, but the intensity recovered immediately upon raising the potential. In addition, b₂‐type bands were observed under rotation even after lowering the potential. The disappearance and reappearance of the b₂‐type bands could also be observed by bringing the sample of 4‐ABT on Ag into contact consecutively with a borohydride solution and water. This is because the surface potential of Ag is lowered by contact with a borohydride solution. Besides, we found that not only the normal Raman but also the SERS spectral features of 4‐ABT are hardly affected by pH variation, while the spectral features of MO are greatly affected, especially in the region of the NN stretching vibration, suggesting that the possibility of a photoconversion of 4‐ABT to an azo compound is low. Altogether, the b₂‐type bands were attributed to 4‐ABT, appearing in conjunction with the chemical enhancement mechanism in SERS. Copyright © 2011 John Wiley & Sons, Ltd.     

粗糙银电极上高铁血红素的非共振表面增强拉曼光谱研究

以632.8nm为激发线,研究了高铁血红素的非共振表面增强拉曼光谱。结果表明,高铁血红素的氧化和还原状态的拉曼谱图以B_(1g)振动模式为主;血红素以丙酸侧基直接吸附于电极表面,叶啉环则以垂直于电极表面的形式存在。B_(1g)振动模式v_(15)对血红素中心铁的氧化还原状态十分敏感,被指认为非共振条件下血红素氧化还原状态的特征谱峰。     

Spectrophotometric investigations of protonated forms of heterocyclic compounds

2,4,6-trimethylpyridine, quinoline, 2-methylquinoline, 4-chlorine-2-methylquinoline, and acridine aromatic heterocycles, as well as protonated forms thereof, are studied by electronic absorption spectroscopy in solution. The influence of protonation on the electronic absorption spectra of heterocycles consists in a long-wavelength shift of the absorption spectrum in comparison with the absorption of initial molecules. The spectra of the protonated forms of all compounds exhibit a relative increase in the intensity of the long-wavelength absorption band compared to the short-wavelength band and a smearing of the vibrational structure in the long-wavelength band.     

Protein adsorption drastically reduces surface‐enhanced Raman signal of dye molecules

There is an increasing interest in developing surface enhancement Raman spectroscopy methods for intracellular biomolecule and for in vitro protein detection that involve dye or protein–dye conjugates. In this work, we have demonstrated that protein adsorption on silver nanoparticle (AgNP) can significantly attenuate the surface‐enhanced Raman spectroscopy (SERS) signal of dye molecules in both protein/dye mixtures and protein/dye conjugates. SERS spectra of 12 protein/dye mixtures were acquired using 4 proteins [bovine serum albumin (BSA), lysozyme, trypsin, and concanavalin A] and three dyes [Rhodamine 6G, adenine, and fluorescein isothiocyanate (FITC)]. Besides the protein/dye mixtures, spectra were also obtained for the free dyes and four FITC‐conjugated proteins. While no SERS signal was observed in protein/FITC mixtures or conjugates, a significantly reduced SERS intensity (up to 3 orders of magnitude) was observed for both R6G and adenine in their respective protein mixtures. Quantitative estimation of the number of dye molecules absorbed onto AgNP implied that the degree of R6G SERS signal reduction in the R6G/BSA sample is 2 to 3 orders of magnitude higher than what could be accounted for by the difference in the amount of the absorbed dyes. This finding has significant implications for both intracellular SERS analyses and in vitro protein detection using SERS tagging strategies that rely on Raman dyes as reporter molecules. Copyright © 2009 John Wiley & Sons, Ltd.