对氨基苯胂酸及其氧化物的色谱研究

用紫外分光光度计分析了对氨基苯胂酸（PABAA）及其氧化物的光谱特征后,在十八烷基键合相硅胶柱上,以甲醇-缓冲液作流动相,研究了二者的容量因子随流动相离子强度、柱温、甲醇含量变化的规律。用季铵盐作离子对试剂,反相离子对色谱法分离PABAA时,分离机理符合高子对机理,在适当条件下,所试验的化合物都可有所保留。对保留值作出贡献的有固定相排阻作用、分配作用以及居次要地位的PABAA与固定相表面剩余硅醇基的相互作用。排阻作用及分配作用的相对重要性与流动相中甲醇和离子对试剂的浓度有关。     

唑来膦酸及其有关化合物的反相离子对高效液相色谱分离

采用反相离子对高效液相色谱法研究了唑来膦酸及其有关化合物的色谱分析与分离方法。优化的分离条件：以Hypersil C8柱为固定相,以甲醇-5 mmol/L磷酸二氢钠缓冲液(含6 mmol/L四丁基溴化铵溶液,用氢氧化钠溶液调节pH至7.0)(体积比为20∶80)为流动相,等度洗脱,流速为1.0 mL/min,紫外检测波长为220 nm,柱温为室温。在该色谱条件下,唑来膦酸与有关化合物(包括其合成过程中残余的原料咪唑乙酸和其他氧化分解产物)的分离良好,与保留时间最接近的杂质峰的分离度大于2.5。该方法不需进     

A Comparison of Radially-Compressed and Stainless Steel Columns for the Reversed-Phase Ion-Pair Separation of Phencyclidine Synthetic Mixtures

Abstract

The reversed-phase ion-pair HPLC separation of phencyclidine synthetic mixtures was optimized utilizing Radial-Pak radially compressed columns. Variables examined in the optimization included column type (C-18, C-8, or CN), pairing ion (methane-, pentane-, hexane-, or octane sulfonates) and mobile phase composition (varying concentrations of methanol or acetonitrile in water). The chromatographic behavior of the phencyclidine mixtures in the various systems utilizing radially compressed columns is compared and contrasted to a similar previous study which examined similar variables on stainless steel columns. The optimum system for radially compressed columns was found to consist of a Radial-Pak C-18 column and a mobile phase of 85:15 MeOH:H₂O, 2.5% acetic acid, 1% triethylamine and 5mM sodium hexane sulfonate.     

Palladium(II) and platinum(II) complexes with N-substituted methionines

Summary As an approach to systems containing methionine residues, 3-acetyl-4-hydroxy-6-methyl-2H-pyran-2-one (HDh, dehydroacetic acid) was treated with L-methionine (MetH) or L-methionine methylester (MetM). By condensation at the acyl group and transfer of the phenolic hydrogen on the nitrogen atom, the related ligands DhMetH and DhMetM, were isolated, and form complexes of formula [MX₂(L)₂](M = Pd or Pt, L = DhMetM, X = Cl, Br or I; L = DhMetH, X = Cl or Br) and [MI₂(DhMetH)] with palladium and platinum dihalides. The reaction of the DhMetK carboxylate with MCl₂ in various media is discussed. Ligands and complexes were characterized by i.r. and n.m.r. (¹H and¹³C) spectroscopy and, in some cases, by thermogravimetric measurements. The ligands behave as monodentate sulphur donors, the 12 complexes showing atrans geometry except for [PtCl₂(DhMetH)₂], which is probably a mixture ofcis andtrans isomers.     

Anionic Palladium(0) and Palladium(II) Ate Complexes

Palladium ate complexes are frequently invoked as important intermediates in Heck and cross‐coupling reactions, but so far have largely eluded characterization at the molecular level. Here, we use electrospray‐ionization mass spectrometry, electrical conductivity measurements, and NMR spectroscopy to show that the electron‐poor catalyst [L₃Pd] (L=tris[3,5‐bis(trifluoromethyl)phenyl]phosphine) readily reacts with Br⁻ ions to afford the anionic, zero‐valent ate complex [L₃PdBr]⁻. In contrast, more‐electron‐rich Pd catalysts display lower tendencies toward the formation of ate complexes. Combining [L₃Pd] with LiI and an aryl iodide substrate (ArI) results in the observation of the Pd^II ate complex [L₂Pd(Ar)I₂]⁻.     

反相离子对高效液相色谱法快速分离和定量测定食品中的甜蜜素

采用反相离子对高效液相色谱法快速分离和测定食品中的甜蜜素。在ODS柱上,以V（甲醇）：V（水,含离子对试剂）=30：70的溶液为流动相进行分离,分别考察了流动相中离子对试剂和甲醇浓度对甜蜜素保留行为的影响。检测波长为205nm;采用外标法定量,测得甜蜜素在0．5～2．5g／L范围内具有良好的线性关系;回收率在96．9％～101．7％之间;检测限为0．05g／L。     

Thin Layer Chromatography of Metal Ions Complexed with Anils (VII) Detection,Separation, and Determination

Abstract

Dark colored chelates of p-dimethylaminoanil of 3-benzoyl-methylglyoxal bidentate ligand with Sb(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), ZrO(II), Y(III), La(III), Pr(III), Nd(III) Sm(III), Gd(III) and Dy(III) have been chromatographed on starch bound silica gel thin layers. New correlations of I.R. with R_f (resolving solvent) have been used to ascertain the colored spots.

Among various mixtures resolved qualitatively a few typical ones have been alanysed quantitatively. Errors in determinations and maximum separation limits have also been deduced.     

Palladium(II) complexes with primary thioamides

Summary Palladium(II) complexes of thioacetamide, thiooxamide,N ^o,N ^o-dimethylthiooxamide and ethyl thiooxamidate have been prepared and investigated by electronic and i.r. spectroscopy. It is concluded that the ligands always act as monodentate sulphur donors, and that planar [PdL₄]X₂ (X = Cl, Br or ClO₄) compounds are formed. The(PdS) frequencies and the ligand field strengths are enhanced by electron donor groups and lowered by electron withdrawing groups.     

Palladium(II) complexes with sulphonium ylides

Keto-stabilized sulphonium ylides displace styrene and benzonitrile from their adducts with PdCl₂ to give stable $\text{2}\text{1}$ ylidePdCl₂ complexes. Evidence is given for epimeric equilibrium between trans square-planar structures of these new complexes in solution.A $\text{1}\text{1}$ ylidePdI₂ complex, obtained from dimethylsulphonium methylide, is also described.     

Chemistry of N,N-Dimethylaminoalkylchalcogenolate Complexes of Palladium(II) and Platinum(II)

Abstract

Four different series of N,N-dimethylaminoalkylchalcogenolates, viz. Me₂NCH₂ CH₂E^?, Me₂NCH(Me)CH₂E^?, Me₂NCH₂CH(Me)E^?, and Me₂NCH₂CH₂CH₂E^? (E = S, Se, Te), (referred as E^∩N) have been synthesized and characterized. Their reactions with palladium(II) and platinum(II) precursors have been explored. Complexes of the general formula, [MCl(E^∩N)]_n, [MCl(E^∩N)₂]_n, [MCl(E^∩N)(PR₃)], [M₂Cl₂(μ-E^∩N)₂(PR₃)₂], [M₂(μ-E^∩N)₂(P^∩P)₂]²⁺, etc. have been isolated. All the complexes have been characterized by elemental analysis, IR, NMR (¹H, ¹³C, ³¹P, ⁷⁷Se, ¹²⁵Te, ¹⁹⁵Pt), UV-vis, and FAB mass spectral data. A weak absorption in the electronic spectra of [MCl(E^∩N)(PR₃)] has been attributed to metal mediated ligand-to-ligand charge transfer and showed pronounced chalcogen dependence being red shifted on moving from S → Se → Te. Structures of several complexes have been established by X-ray diffraction analyses. Thermal behavior of some of these complexes has been investigated by TGA.     

表阿霉素及其相关物质在反相离子对色谱中的色谱行为

以表阿霉素及其6种相关物质为研究对象,系统评价了其在反相离子对色谱模式下的色谱行为.分别考察了流动相中有机相种类、有机相比例、水相中离子对试剂浓度、pH值对表阿霉素及其相关物质的影响.结果表明,使用乙腈作为有机相洗脱能力及分离效果优于甲醇,保留时间随乙腈比例增大而减小;随着离子对试剂十二烷基硫酸钠浓度增加,杂质阿霉素酮及柔红霉酮几乎无影响,其他5种物质保留时间增加.同时,表阿霉素及其杂质的保留行为受流动相pH值影响较大,当pH不高于4时可获得较好的分离效果.通过对表阿霉素及其相关物质反相离子对模式下的保留行为进行了系统的评价和定量描述,研究结果将有助于该类化合物液相色谱分离方法的发展.     

Carbonyl Complexes of Platinum (II) and Palladium(II) with Heterocyclic Cyclometalating Ligands

Russian Journal of General Chemistry -     

Palladium(II) iminophosphine complexes

New complexes of general formula [PdCl₂(NP)] (NP = o-Ph₂PC₆H₄-CH=N-R; R = Me, ⁱ Pr, ^t Bu, NH-Me) and [Pd(NP)₂](ClO₄)₂ (NP = o-Ph₂PC₆H₄-CH=N-R; R = Me, ⁱ Pr) have been prepared by directly reacting the precursor PdCl₂(PhCN)₂ with iminophosphines (NP) in 1:1 and 1:2 molar ratios respectively. When the chloro-complex [PdCl₂(o-Ph₂PC₆H₄-CH=N ⁱ -Pr)] was treated with CF₃SO₃Ag in MeCN, the labile complex [Pd(o-Ph₂PC₆H₄-CH=N ⁱ -Pr)(MeCN)₂](CF₃SO₃)₂ was obtained in good yield. The reactivity of the new precursor towards a variety of neutral N- and P-donor ligands (py, PMe₂Ph, PMePh₂, PEt₃, bipy, dppe, 2-thpy) has been studied. The new complexes were characterized by partial elemental analyses and by spectroscopy (i.r., ¹H- and ³¹P-n.m.r.). The molecular structure of the aquo-complex [Pd(NP)(2-thpy)(H₂O)](CF₃SO₃)₂ has been determined by a single-crystal diffraction study, showing that the iminophosphine acts as a chelating ligand with coordination around the palladium atom slightly distorted from square-planar geometry.     

Palladium(II) methylpyrazole complexes

Summary Pd^II complexes of the general formula PdL ₂ ⁿ Cl₂ [L¹ = 3,4,5-trimethylpyrazole, L² = l,3,4-trimethylpyrazole, L³ = 1,3,5-trimethylpyrazole, L⁴ = 1,4,5-trimethylpyrazole and L⁵ = 1,3,4,5-tetramethylpyrazole] (1)–(5) have been prepared and studied by elemental analyses, X-ray diffraction patterns, i.r., far-i.r. and n.m.r. spectroscopy, conductometry, magnetic and thermal measurements.     

Ion-Pair Reversed-Phase Thin-Layer Chromatography and High-Performance Liquid Chromatography of Benzoic Acids

The separation of benzoic acids by ion-pair reversed-phase thin-layer chromatography and high-performance liquid chromatography was studied. In the optimization of separation conditions, the effect of the nature and concentration of the organic solvent, acidity of the mobile phase, concentration of salts of quaternary ammonium bases, and the length of their hydrocarbon radical on the retention of benzoic acids was studied. Conditions of the separation of a mixture of benzoic, hydroxybenzoic, aminobenzoic, and nitrobenzoic acids on Silufol plates impregnated with cetyltrimethylammonium bromide were selected; the mobile phase was isopropanol–ammonium acetate buffer solution with pH 5–dodecyltrimethylammonium bromide.     

Palladium (II) and platinum (II) complexes with 2,5-dimethylbenzoxazole and 2,5-diphenyloxazole

Some 2,5-diphenyloxazole (PPO) and 2,5-dimethylbenzoxazole (Me₂BO) complexes of palladium (II) and platinum (II) have been prepared and their molar conductivities, i.r. and electronic spectra are reported and discussed. The PPO generally acts as monodentate N-bonded, while the Me₂BO behaves as monodentate O-bonded. The complexes are generally trans-square planar.     

Sulfobridged Polynuclear Complexes of Platinum(II) and Palladium(II)

When the platinum(II) and palladium(II) salts interact with ligands such as cystamine-(mercamine) HSCH₂CH₂NH₂ and 2-mercaptoethanol HSCH₂CH₂OH under certain conditions, polynuclear complexes of the compositions are obtained: [Pt₆(SCH₂CH₂NH₂)₈]Cl₄. 5H₂O and [Pd₆(SCH₂CH₂OH)₈]Cl₄. In a comparative study of the IR and X-ray spectra of synthesized complexes and ligands, as well as the results of X-ray diffraction studies, it was established that sulfur atoms of 2-mercaptoethanol occupy a bridge position with a mixed coordination of ligands in the palladium complex. In the platinum(II) complex bidentate coordination of ligands is realized through sulfur and nitrogen atoms.     

Nitrosodicyanmethanid-Komplexe von Palladium(II) und Platin(II)

Crystal and Molecular Structure of 1,8-Dihydroxy-3,6-dithiaoctan-bis-mercury(II) Chloride The crystal structure of 1,8-dihydroxy-3,6-dithiaoctane-bis-mercury(II) chloride has been determined by X-ray crystal structure analysis. The compound crystallizes monoclinic, space group C2/c with a = 15.311(2), b = 5.870(2), c = 17.479(2) Å, β = 102.76° and 4 formula units per unit cell. The structure was solved by heavy atom technique and refined to a final R value of R = 0.050. Mercury is digonally coordinated by an S and a Cl ligator. In consequence of weak interactions to an oxygen atom of the ligand as well as to three further Cl ions the coordination number is increased to six and a strongly distorted octahedron is formed. The crystal structure is built up from polymeric complex molecules.