Investigation of thin-layer chromatography properties of some transition metal complexes based on ditiocarbamates

Sodium diethyldithiocarbamate (DEDTC) and ammonium pyrolidinedithiocarbamate (PyDTC) are prepared as their Co or Cu (M) complexes [M(DEDTC)(2) and M(PyDTC)(2), respectively]. The complexes are prepared by reactions of DEDTC and PyDTC with metal (II) nitrates, and they are examined for chromatographic properties using thin-layer chromatography systems. These complexes and their mixtures are spotted on the activated and non-activated 250-microm thick thin layers of commercial silica gel (Si-60GF(254)). Pure toluene and a toluene-cyclohexane mixture (3:1, v/v) are used as mobile phases for running the complexes. These chromatographic systems are successfully used for the qualitative analysis of the corresponding metal cations and the separation of components in both M(DEDTC)(2) and M(PyDTC)(2) complex mixtures. In addition, non-activated layers are more successful than activated layers. This study may be useful in understanding the effects of stationary and mobile phase properties, retention mechanisms, and the effects of the nature of metal and ligand type on the chromatographic behavior and parameters [e.g., retention factors, theoretical plate numbers, and resolution] of the complexes.     

N-亚水杨基亮氨酸3d金属配合物的合成及薄层色谱与紫外光谱研究

合成了亮氨酸水杨醛希夫碱及其与Ｍｎ（Ⅱ）,Ｃｏ（Ⅱ）,Ｎｉ（Ⅱ）,Ｃｕ（Ⅱ）,Ｚｎ（Ⅱ）的配合物。元素分析和摩尔电导测定的结果证明,亮氨酸水杨醛希夫碱３ｄ金属配合物配位比为１１,配合物在ＤＭＦ中为非电解质。在硅胶Ｇ板上,以乙酸乙酯－甲醇－丙酮－水－乙酸（４．４４３．３３２．２２０．２５０．１２,Ｖ／Ｖ）为流动相,研究了配合物的薄层色谱行为,各组分配合物的比移值Ｒｆ值相差较大,得到满意的分离,且Ｒｆ值按下列顺序递增Ｍｎ＜Ｚｎ＜Ｎｉ＜Ｃｕ＜Ｃｏ。讨论了系列配合物薄层色谱Ｒｆ与紫外光谱Ｒ带λｍａｘ变化关系的规律     

Chromatographic separation of some metal ions on NTA-impregnated thin-layer plates

Summary NTA (nitrilo triacetic acid) has been used as an impregnating agent for an efficient TLC separation of twelve metal ions, using a mixture of 5% aq ammonia, ethanol acetone and acetic acid as the solvent system and dithizone (0.5% in chloroform) for visualization.     

Non-aqueous,reversed-phase,high-performance,thin-layer chromatography and column liquid chromatography of metal complexes of porphine

Summary The chromatographic mobility of 21H, 23H-porphine and its Ni(II), Cu(II), Zn(II) and Pd(II) complexes were investigated by high-performance thin-layer chromatography on an octadecyl-bonded, silica gel plate with various polar organic solvents including alcohols, acetonitrile, dimethylsulfoxide and propylenecarbonate. The mobility generally decreases according to the central metal ion of the complex as follows: Zn(II)>(free porphine)>Ni(II)>Pd(II)>Cu(II). Methanol is a good choice of solvent for the separation of these metal porphine complexes. Successful separation of porphine and the four metal complexes is accomplished within 13 min on a LiChrosorb RP-18 column with methanol eluent.     

Salting-out thin-layer chromatography of transition metal complexes. IV: Effect of sorbent on the behaviour of mixed aminocarboxylato cobalt (III) complexes

Summary From literature data for 14 mixed aminocarboxylato cobalt(III) complexes, the effect of the sorbent on R_M values, salting-out efficiency (m) and separation factors () of adjacent members of homologous series was investigated in salting-out, thin-layer chromatography on silica gel, polyacrylonitrile and cellulose sorbents, using ammonium sulphate solutions as developers. For complexes belonging to the same homologous series, linear dependence was found between R_M,m and log values, respectively, on two different sorbents. Polyacrylonitrile was shown to be the most suitable sorbent for the separation of the complexes since it gave the highest values for R_M,m and .     

High-performance thin-layer chromatography of metal complexes ofmeso-tetrakis(p-tolyl)porphyrin on cellulose and silica gel

Summary The migration behavior of metal complexes ofmeso-tetrakis(p-tolyl)porphyrin (TTP) are studied in HPTLC systems with cellulose and silica gel thin-layers and various organic solvents of relatively low polarity. The mobility of the metal complex tends to increase in the following orders of its central-metal elements: on cellulose, Mg(II)<Zn(II)<V(IV)<(H)<Pd(II)< Ni(II)Cu(II); on silica gel, Mg(II)<V(IV)<Zn(II)= (H)<Ni(II)Pd(II)Cu(II). Recommendable phase system for the separation of metal-TTP complexes is a combination of silica gel thin-layer with a carbon disulfide-m-xylene mixture though the complexes of Ni, Cu and Pd are not completely resolved.     

Coupling of narrow-bore liquid chromatography to thin-layer chromatography : Part I. Interfacing

The coupling of liquid chromatography (l.c.) on narrow-bore columns to thin-layer chromatography (t.l.c.) is described. The effluent from a l.c. column can be deposited on a t.l.c. plate after a normal-phase or reversed-phase separation without serious loss of chromatographic information. Both silica and alkyl-modified silica plates can be used for storage. The interface is a fused silica capillary which connects the column outlet to the spray jet assembly of a Linomat applicator for t.l.c. The stored chromatogram can serve as starting point for a new separation, but also allows the use of detection principles which are normally not compatible with l.c. The chromatography of some polynuclear aromatic hydrocarbons is used to illustrate the possibilities of the combinations.     

Ethers as ligands. Part VI. Transition metal(II) complexes with 18-crown-6

Summary Seven new coordination compounds are reported with the cyclicpolyether 18-crown-6 as the ligand,viz. [Mg(18-crown-6) (H₂O)₂](SbCl₆)₂, [M(18-crown-6)(MeNO₆)₂](SbCl₆)₂ with M is Ca²⁺ and Sr²⁺, [M(18-crown-6)(MeNO₂)](SbCl₆)₂ with M is Mn²⁺ and Co²⁺, and [M(18-crown-6)](SbCl₆)₂ with M is Ni²⁺ and Zn²⁺.     

Chromatographic analysis of blood lipids. Comparison between gas chromatography and thin-layer chromatography with flame ionization detection

Intact human blood plasma lipids of different composition were analyzed by gas chromatography and thin-layer chromatography with flame ionization detection. The reproducibility of the results obtained by gas and thin-layer chromatography was compared. The main advantages and disadvantages of both methods for lipid analysis are discussed. Generally, the variability of the results measured by thin-layer chromatography in series and from day to day was greater than that obtained by gas chromatography.     

Chromatographic analysis of penstemide and serrulatoloside by high-performance liquid chromatography and gradient thin-layer chromatography

Summary A sensitive capillary gas chromatographic method is described for the simultaneous determination of lidocaine, tetracaine, procaine and dibucaine. The method was applied to the determination of anesthetics in tissue homogenates incubated at 38°C at doses between 10 and 400 mg/kg. In the liver tissue thein vitro metabolization of the studied anesthetics is most rapid for tetracaine, also fast for procaine, while for lidocaine and dibucaine the metabolization is very slow. In brain tissue thein vitro metabolization of anesthetics is very slow.The method shows good analytical parameters: linearity between 5 and 40 g/ml; day-to-day reproducibility ca. 8% for a concentration of 20 g/ml, precision ca. 7% for a concentration of 20g/ml. Accuracy is also very good.     

Reversed-phase,high-performance,thin-layer chromatography of metal tetrakis (p-tolyl) porphine complexes on octadecylbonded stationary phase

Summary The metal complexes ofmeso-tetrakis (p-tolyl) porphine (TTP) are chromatographed on octadecyl-bonded silica gel thin-layer with various organic solvents of relatively high polarity used as the eluent. The mobility of the metal-TTP complex depends on its centralmetal, increasing in the order of Cu(II)<Pd(II)NI(II)<TTP free acid<V(IV) as vanadyl<Zn(II)<Mg(II), although some irregularities are found with the different developing solvents used. The concept of Hildebrand's solubility parameter is applied to the discussion of the mobility of each compound, on the solvents used as the developer. Successful separation of the TTP compounds is performed by using a mixture of acetone and acetonitrile as the developer, although the Ni- and Pd-complexes are not completely resolved.     

Transition metal ion complexes of thiosemicarbazones derived from 2-acetylpyridineN-oxide. Part III. Spectral and thermal studies of the metal complexes of 2-acetylpyridineN-oxide thiosemicarbazone

Summary Metal complexes of 2-acetylpyridineN-oxide thiosemicarbazone have been prepared and characterized. Coordination occurs as a neutral bidentate (ON) and a deprotonated tridentate (ONS) ligand.     

Investigation of the interaction of olefin-bonded transition metal complexes by gas chromatography. II. Phosphine complexes of Cu(II)

Summary Packings consisting of chemically bonded diphenylphosphine complexes with CuCl₂ and CuBr₂ were synthesized and their retention parameters determined. The packings investigated are capable of specific interactions with electron-donating compounds and are characterized by particularly high selectivity in relation to cis and trans isomers allowing their complete separation.Part 1: see ref. [1]     

Crystallographic and structural characterization of heterometallic platinum complexes Part VI. Heterohexanuclear complexes

This review classifies and analyzes heterohexanuclear platinum clusters into seven types of metal combinations:Pt₅M, Pt₄M₂, Pt₃M₃, Pt₂M₄, PtM₅, Pt₂M₃M′, and Pt₂M₂M₂′. The crystals of these clusters generally belong to six crystal classes: monoclinic, triclinic, orthorhombic, tetragonal, trigonal and cubic. Among the wide range of stereochemistry adopted by these clusters, octahedral and capped square-pyramidal are the most common. Although platinum is classified as a soft metal atom, it bonds to a variety of soft, borderline and hard metals. Nineteen different heterometal ions are involved in hexanuclear platinum clusters. The shortest Pt-M bond distance in the case of M being a non-transition element is 2.395(4) Å for germanium and for M being a transition metal ion it is 2.402(2) Å for Cobalt. The shortest Pt-Pt bond distance observed in these clusters is 2.532 Å. Several relationships between the structural parameters are identified and discussed. Some clusters exist in two isomeric forms and some show crystallographically independent molecules within the same crystal. Such isomers and independent molecules are examples of distortion isomerism.      

Chemically-bonded stationary phases for thin-layer chromatography of metal ions

Summary A numer of bonded stationary phases were investigated for the separation of Cd²⁺, Cu²⁺, Fe³⁺, Mn²⁺, Ni²⁺, Pb²⁺, and Zn²⁺ by thin-layer chromatography. The effect of structure, surface loading, type of silica gel and mobile phase concentration was considered.