Manganese complexes chromatography

Massa, V. Microdetermination of manganese by chromatography and photodensitometry of its complex with l-(2-pyridylazo)-2-naphthol. Trav. Soc. Pharm. Montpellier 29, 257 (1969) C. A. 73, 113 036s (1970)... 

Metal Complex. Complexation gas chromatography was first introduced by V. Schurig in 1980 (118) and employs transition metals (eg, nickel, cobalt, manganese or rhodium) complexed with chiral terpenoid ketoenolate ligands such as 3-ttifluoroacetyl-lR-camphorate (6),... 

Other methods reported for the determination of beryllium include UV-visible spectrophotometry [80,81,83], gas chromatography (GC) [82], flame atomic absorption spectrometry (AAS) [84-88] and graphite furnace (GF) AAS [89-96]. The ligand acetylacetone (acac) reacts with beryllium to form a beryllium-acac complex, and has been extensively used as an extracting reagent of beryllium. Indeed, the solvent extraction of beryllium as the acety-lacetonate complex in the presence of EDTA has been used as a pretreatment method prior to atomic absorption spectrometry [85-87]. Less than 1 p,g of beryllium can be separated from milligram levels of iron, aluminium, chromium, zinc, copper, manganese, silver, selenium, and uranium by this method. See also Sect. 5.74.9. 

Resolution of a racemic mixture is still a valuable method involving fractional crystallization [113], chiral stationary phase column chromatography [114] and kinetic resolutions. Katsuki and co-workers demonstrated the kinetic resolution of racemic allenes by way of enantiomer-differentiating catalytic oxidation (Scheme 4.73) [115]. Treatment of racemic allenes 283 with 1 equiv. of PhIO and 2 mol% of a chiral (sale-n)manganese(III) complex 284 in the presence of 4-phenylpyridine N-oxide resulted... 

The trimethylsilylated silicic acids formed in this instance are soluble in conventional organic solvents, and their volatility is sufficiently high for them to be analysed by gas chromatography. Carzo and Hoebbel [411] carried out a comprehensive study of the chromatographic retention of various trimethylsilylated silicic acids on different stationary phases Apiezon L and silicone OV-1 and OV-17. The analysis of metals in the form of volatile complexes continues to attract attention, and have been described for analysing sodium [412], potassium [412], radium [413], caesium [413], barium [414], calcium [414], strontium [415], beryllium [416, 417], magnesium [418], zinc [419, 420], nickel [419], mercury [421], copper [422, 423], silver [424, 425], cadmium [421], indium [426, 427], g ium [428], scandium [217], cobalt [421], thallium [426], hafnium [429, 430], lead [431, 432], titanium [430], vanadium [433], chromium [434-436], manganese [426], iron [437], yttrium [438], platinum [439,440], palladium [439, 441, 442], zirconium [430], molybdenum [443], ruthenium [444], rhodium [445], rare earths [446—449], thorium [221, 450, 451] and uranium [221, 452]. The literature on GC analysis of metal chelates was reviewed by Sokolov [458]. 

Optically active manganese (III) complex, Cyclo-Salen-Mn (III)Cl, was prepared by the reported method and purified with column chromatography on silica-gel or washing its benzene solution with aqueous lithium chloride solution. Ph-P-diketone-... 

To date, the smallest particle capable of water photolysis contains at least six intrinsic membrane proteins and one extrinsic polypeptide. A number of reports on the study of the components essential for water oxidation, their location and interactions has appeared. The involvement of the extrinsic 33kD protein and its potential for manganese stabilisation has also been the subject of numerous reports (for review see 5). Nevertheless, the binding site(s) of this polypeptide to the intrinsic core of photosystem 2 has not been unequivocally determined. We recently showed, by means of affinity chromatography, that there is a preferential association of the extrinsic 33kD protein with the Dl/D2/cytochrome b-559 reaction centre rather than the other protein components of the photosystem 2 core complex (6). 

Commercial manganese dioxide (405 mg) is added to a solution of the iron complex (81 mg, 0.188 mmol) in toluene (3 mL). The mixture is stirred for 1 h at room temperature and filtered over a short path of Celite that is subsequently washed with diethyl ether several times. The filtrate is evaporated and the yellow crude product is subjected to flash chromatography (hexane/ethyl acetate 5 1) on degassed siliea gel to provide the complex as a yellow solid mp > 80 °C (decomp.) 66 mg (85%). ... 

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