化学衍生—高效液相色谱法测定硫氰酸根阴离子

以α－溴２，３，４，５，６－五氟甲苯作柱前衍生试剂，经优化衍生和色谱条件，实现了用高效液相色谱法测定硫氰酸根离子。在ＯＤＳ柱上，用甲醇－水（８０：２０）作流动相，于２５４ｎｍ检测，得到线性关系良好的工作曲线，最小检测限为４．７ｎｇ。分析了吸烟者唾液样品，回收率为９３．７％～１０１．４％。     

抑制型离子色谱快速测定I^—,SCN^—,S2O^2—3

本用抑制型离子色谱，薄壳强碱性阴离子交换树脂为分离柱，柱温为３０±１℃，在常规淋洗液ＮａＨＣＯ３－Ｎａ２ＣＯ３中加入对－硝基苯酚作为有机改进剂，测定了Ｉ＾－、ＳＣＮ＾－、Ｓ２Ｏ＾２－３离子。它们有良好的线性关系，三种离子浓度在５．０～３０．０ｍｇ／Ｌ范围内其相关系数分别为：ｒＩ＾－０．９９９４、ｒｓｃｎ＾－０．９９０６、ｒｓ２ｏ＾２－３０．９９８５，检测限分别为：Ｉ＾－０．１７ｍｇ／Ｌ、ＳＣＮ＾     

柱前衍生非不毛细管电泳分离钴,镍和铜

提出柱前衍生非水毛这电泳分离金属离子的方法，应用新合成的２－（６－甲基－２－苯并噻唑偶氮）－５－二乙胺基酚作为柱前衍生试剂，乙醇和Ｎ，Ｎ－二甲基甲酰胺为非水溶剂，在６ｍｉｎ内实现了钴、镍和铜的分离，灵敏度高，检测限分别为９．１８×１０＾－８ｍｏｌ／Ｌ、２．７９×１０＾－７ｍｏｌ／Ｌ和４．４７×１０＾－７ｍｏｌ／Ｌ，考察了柱前衍生条件、非水溶剂配比以及分离参数对分离的影响。     

离子对高效液相色谱－TPPS_4光度法测定痕量锰锌铜的研究

本实验用磺化四苯基卟啉作柱前衍生试剂，研究了在Ｈｇ（Ⅱ）催化下，于ｐＨ５．５时，ＴＰＰＳ_４与Ｍｎ（Ⅱ）、Ｚｎ（Ⅱ）、Ｃｕ（Ⅱ）的配位反应，提出了以苄基三乙基氯化铵作离子对试剂，反相离子对高效液相色谱－光度法分离和测定痕量Ｍｎ（Ⅱ）、Ｚｎ（Ⅱ）、Ｃｕ（Ⅱ）的新方法，检测下限（×１０~（－９）ｇ／ｍＬ）：Ｍｎ~（２＋）０．１５，Ｚｎ~（２＋）０．２０，Ｃｕ~（２＋）０．１１。所确立的方法用于茶汤中锰、锌、铜的测定，结果满意。     

离子对高效液相色谱—TPPS4光度法测定痕量锰锌铜的研究

本实验用磺化四苯基卟啉作柱前衍生试剂，研究了在Ｈｇ（ＩＩ）催化下，于ＰＨ５．５时，ＴＰＰＳ４与Ｍｎ（ＩＩ），Ｚｎ（ＩＩ），Ｃｕ（ＩＩ）的配位反应，提出了以苄基三乙基氯化铵作离子对试剂，反相离子对高效液相色谱－光度法分离和测定痕量Ｍｎ（ＩＩ），Ｚｎ（ＩＩ），Ｃｕ（ＩＩ）的新方法，检测下限（×１０＾－９ｇ／ｍＬ）：Ｍｎ＾２＋０．１５，Ｚｎ＾２＋０．２０，Ｃｕ＾２＋０．１１。所确立的方法用于茶汤中锰，锌     

高效液相色谱法快速,灵敏测定尿中3—甲基组氨酸含量

本文报道用柱前衍生高液相色谱法快速，灵敏地测定尿中３－甲基组氨酸（３ＭＨ）。采用含３０％乙腈的１０ｍｍｏｌ／Ｌ磷酸钠缓冲液（ｐＨ＝７．５）为流动相，等梯度洗脱，１０ｍｉｎ内即可分析一个样品；在２０－３０００ｐｍｏｌ范围内，３ＭＨ线性相关系数为０．９９８６，相对标准偏差为２．３％（批内）和４．５％（批间）；并测定了１０名正常人尿中的３ＭＨ含量。     

化学衍生—高效液相色谱法同时测定铅（Ⅱ）和汞（Ⅱ）

从吡啶－２－乙醛苯甲酰腙作柱前衍生试剂，在优化了衍生和色谱条件下实现了用高效液相以谱法同时测定铅和汞离子，在ｐｈｅｎｏｍｅｎｅｘｓｐｈｅｒｅｘＣ１８色谱柱上，用甲醇－水（６５：３５，Ｖ／Ｖ），作流动相，于２４８ｎｍ处检测，得到线性良好的工作曲线，铅和汞的最低检测限分别为２．５５μｇ／Ｌ和７．２９μｇ／Ｌ。分析了环境水样品和合成水样，铅和汞的标准加入回收率分别为９８．３％～１０１．７％和９８．０～１     

离子色谱法测定α—氧化铝中微量硫酸根的研究

本建立了用氢氧化钠溶样，离子色谱测定α－Ａｌ２Ｏ３中微量硫酸根的方法。在ＤｉｏｎｅｘＡＳ４Ａ分离柱上，用１．８×１０＾－＾３ｍｏｌ／ＬＡａ２ＣＯ３作流动相进行洗脱，电导检测器检测，分析方法简便，快速，硫酸根的检测限为１．０×１０＾－＾２μｇ／ｍｌ，相对标准偏差为２．６７％，回收率为９７．５％，扩展了离子色谱法测定实际样品的范围。     

反相离子对高效液相色谱法分离测定痕量镍（Ⅱ）锌（Ⅱ）铜（Ⅱ）

用二甲酚橙作柱前衍生试剂，在Ｃ１８色谱柱上，以乙腈－水（１２：８８，Ｖ／Ｖ）作流动相，六次甲基四胺为对离子试剂，反相离子对高效液相色谱－光度法快速分离测定痕量Ｎｉ＾２＋，Ｚｎ＾２＋，Ｃｕ＾２＋配合物和试剂在８ｍｉｎ内出峰完毕，５７５ｎｍ处检测，检出限分别为（ｎｇ／ｍＬ）：Ｎｉ＾２＋０．８３，Ｚｎ＾２＋０．０１，Ｃｕ＾２＋，１．３０，用于植物样品中Ｎｉ＾２＋，Ｚｎ＾２＋，Ｃｕ＾２＋的测定，结果令人满     

离子色谱法快速同时测定营养药物中微量铜、锰、锌

在ＨＰＬＣ－ＣＳ５阳离子分离柱上选用５．０×１０￣（－２）ｍｏｌ／Ｌ草酸（ｐＮ为５．２４）作淋洗液分离了微量Ｃｕ￣２＋、Ｍｎ￣２＋和Ｚｎ￣２＋离子,用４－（２－吡啶偶氮基）间苯二酚作显色剂在５２０ｎｍ处连续检测,方法快速、简便、准确。本法用于施尔康片中微量Ｃｕ￣２＋、Ｍｎ￣２＋和Ｚｎ￣２＋离子的测定,结果令人满意。     

Organogermyl,Organostannyl, and Organoplumbyl Phosphines,Arsines, Stibines,and Bismuthines

The preparation, properties, and reactions of the compounds named in the title are described, with particular reference to the possible participation of (p→d)_π components in the bonding between the group IVB and the group VB elements.     

Pyrenes,Peropyrenes, and Teropyrenes: Synthesis,Structures, and Photophysical Properties

The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems.     

Pyrenes,Peropyrenes, and Teropyrenes: Synthesis,Structures, and Photophysical Properties

The design of a relatively simple and efficient method to extend the π‐conjugation of readily available aromatics in one‐dimension is of significant value. In this paper, pyrenes, peropyrenes, and teropyrenes were synthesized through a double or quadruple benzannulation reaction of alkynes promoted by Brønsted acid. This novel method does not involve cyclodehydrogenation (oxidative aryl–aryl coupling) to arrive at the newly incorporated large arene moieties. All of the target compounds were synthesized in moderate to good yields and were fully characterized with the structures unambiguously confirmed by X‐ray crystallography. As expected, photophysical characterization clearly shows increasing red‐shifts as a function of extended conjugation within the fused ring systems.     

Structural, magnetic, and spectroscopic studies of YAgSn, TmAgSn, and LuAgSn

The rare earth-silver-stannides YAgSn, TmAgSn, and LuAgSn were synthesized from the elements by arc-melting and subsequent annealing. The three stannides were investigated by X-ray powder and single-crystal diffraction: NdPtSb type, P6₃mc, Z=2, a=468.3(1), pm, wR₂=0.0343, 353 F² values, 12 variables for YAgSn, and ZrNiAl type, P6¯2 m, a=726.4(2), , wR₂=0.0399, 659 F² values, 15 variables for TmAgSn, and a=723.8(2), , wR₂=0.0674, 364 F² values, 15 variables for LuAgSn. Besides conventional laboratory X-ray data with monochromatized Mo radiation, the structures were also refined on the basis of synchrotron data with , in order to clarify the silver-tin ordering more precisely. YAgSn has puckered, two-dimensional [AgSn] networks with Ag-Sn distances of 278 pm, while the [AgSn] networks of TmAgSn and LuAgSn are three-dimensional with Ag-Sn distances of 279 and 284 pm for LuAgSn. Susceptibility measurements indicate Pauli paramagnetism for YAgSn and LuAgSn. TmAgSn is a Curie-Weiss paramagnet with an experimental magnetic moment of 7.2 μ_B/Tm. No magnetic ordering is evident down to 2 K. The local environments of the tin sites in these compounds were characterized by ¹¹⁹Sn Mössbauer spectroscopy and solid-state NMR (in YAgSn and LuAgSn), confirming the tin site multiplicities proposed from the structure solutions and the absence of Sn/Ag site disordering. Mössbauer quadrupolar splittings were found in good agreement with calculated electric field gradients predicted quantum chemically by the WIEN2k code. Furthermore, an excellent correlation was found between experimental ¹¹⁹Sn nuclear magnetic shielding anisotropies (determined via MAS-NMR) and calculated electric field gradients. Electronic structure calculations predict metallic properties with strong Ag-Sn bonds and also significant Ag-Ag bonding in LuAgSn.     

Borinium, borenium, and boronium ions: synthesis, reactivity, and applications

Boron cations are elusive and highly electrophilic species that play a key role in the chemistry of boron. Despite early interest in the chemistry of boron cations, until recently they have largely remained chemical curiosities. However, hints at harnessing their potential as potent electrophiles have begun to appear and developments in weakly coordinating anion technology suggest that this is an area of research that is ripe for exploration. It has been nearly 20 years since the last major review on boron cations; herein we summarize the progress in the area since that time.     

Pi bonding and negative hyperconjugation in mono-, di-, and triaminoborane, -alane, -gallane, and -indane

A systematic quantum chemical investigation of mono-, di-, and triaminoborane, -alane, -gallane, and -indane is carried out to determine quantitatively the effects of pi bonding and negative hyperconjugation on structures, energetics, and rotational barriers in these systems. Pi bonding plays a significant role in the aminoborane compounds, but becomes rapidly less significant in the aminoalanes, -gallanes, and -indanes. For each main-group metal X investigated, X-N rotational barriers are found to be essentially equal depending only on the number of remaining in-plane amino groups. The contribution of negative hyperconjugation to reducing rotational barriers, as assessed from natural bond orbital (NBO) delocalization energies, is independent of the pyramidalization of the out-of-plane amino group, and is also dependent only on the number of rotated groups. Optimized tris[bis(trimethylsilyl)amino]-substituted structures of boron, aluminum, gallium, and indium are found to compare quite well with available experimental structural data, and exhibit X-N torsion angles that are independent of the central metal atom.     

Transition-metal-free O-, S-, and N-arylation of alcohols, thiols, amides, amines, and related heterocycles

A new protocol for the Ullmann-type arylation process of different aromatic heterocycles without any transition-metal catalyst, implying the use of a combination of an excess of potassium hydroxide and dimethyl sulfoxide, is described. The reaction can be performed between a broad range of starting nucleophiles including phenol, alcohols, amines, nitrogen-containing five-membered systems such as pyrazoles, imidazoles, and indoles, and amides with haloarenes, iodide and bromide derivatives giving the best results, the possible pathway involving the in situ generation of the corresponding benzyne intermediate. When the reaction was performed with 2-iodoaniline and either carboxamides or isothiocyanato derivatives, the corresponding benzoazole derivatives were obtained.     

Metal-Directed Formation of Tetra-, Hexa-, Octa-, and Nonanuclear Complexes of Magnesium,Calcium, Manganese,Copper, and Cadmium

Efficacious metal control of self-assembly of dialkylketipinate dianions leads to completely different supramolecular assemblies. The structures of grid 1 , double-decker 2 , triple-decker 3 , and metalla-spherand 4 were characterized by X-ray crystallographic analyses or by NMR spectroscopy.     

Synthesis of yttrium,lanthanum, neodymium,praseodymium, and lutetium alkoxides and acetylacetonates

A convenient and practical method is proposed for the synthesis of lanthanide and yttrium alkoxides. The method involves dissolving the metals or their hydrides in a solution of dry HCl in the corresponding alcohol, with subsequent dehalogenation of the LnCl₃ solution by an equivalent amount of alkali metal (Na, Li), The rareearth alkoxides are easily converted into acetylacetonates Ln(acac)₃ by the action of acetylacetone.A. N. Nesmeyanov Institute of Elementoorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2490–2493, November, 1992.