Chromium complexes chloro

The fact that from a chloro-cobalt complex a chloro-chromium complex is formed, suggests that the reaction must proceed through an intermediate state that enables the transfer of a chlorine atom from cobalt to chromium. The proposed mechanism for this reaction is ... 

All three (t7 CsH5)M(NO)2C1 complexes are prepared in a similar manner, but to achieve maximum yields of the chromium and tungsten compounds, the reactions must be performed at -78°. The molybdenum complex (chloro(Tj -cyclopentadienyl)nitrosylmolybdenum), on the other hand, can be obtained in excellent yields even at room temperature and its preparation is detailed below. 

An example, developed by our group, has been presented 3-chloro-propenyl pivalate, the new synthon we propose as a formal a-hydroxy allyl anion, and chromium(II) chemistry allow to achieve the formal diastereo- and enantio-selective a-hydroxyallylation of carbonyl compounds by applying a catalytic cycle based on an in situ produced Salen-chromium complex (Table 8.3). 

The chromium-complexed propargyl alcohols are useful compounds for further organic transformation. For example, the treatment of 60 with thionyl chloride or chlorodiethylphosphite to give the chloro- or phosphorylallenyl substituted arene chromium complexes in good yields (Eq. 46) [46]. The phosphorylallenyl substituted q -arene chromium complexes have been developed in further cyclization reactions (Eq. 47). 

CAS 6408-31-7 EINECS/ELINCS 229-054-5 Synonyms Benzenesulfonic acid, 5-chloro-3-[[4,5-dihydro-3-methyl-5-oxo-1-(3-sulfophenyl)-1H-pyrazol-4-yl] azo]-2-hydroxy-, chromium complex Chromate (2-), (5-chloro-3-((4,5-dihydro-3-methyl-5-oxo-1-(3-sulfophenyl)-1H-pyrazol-4-yl) azo)-2-hydroxybenzenesulfonato (4-)) hydroxy-, disodium Cl 18800 Classification Chromium complex azobenzene Empirical CieHioCICrN409S2 2Na Properties Dk. rustpowd. m.w. 599.81 Toxicology ACGIH TWA 0.5 mg(Cr)/m prevent inh. and direct contact with skin and eyes TSCA listed... 

CgH, Phenyl, platinum complex, 26 136 CgHjCI, Benzene, chloro-, chromium complex, 28 139... 

Step 2 The electron transfer from Cr (II) to Co (III) in the bridged activated complex occurs through the chloro bridge. This results into oxidation of Cr (II) to Cr (III) and reduction of Co (III) to Co (II). Step 3 The Cr (III) attracts the Cl ion more strongly, as compared to Co (II). Due to this, the chloro ligand becomes a part of the chromium complex in the final product. 

Some of the baths which contain complexes of the deposited metal are not alkaline and do not contain cyanide, but other ligands. Chromium is plated from a solution of chromic acid, tin is likewise plated from a solution of its oxy-complex. Chloro complexes are also sometimes used for gold plating and many other complexes are used for special purposes. 

The fact that the pH values of the pure metals were lower than the theoretical values was attributed to the formation of hydroxy-chloro complexes of the metal and to the high chloride ion concentration in the pit, and the results highlight the very pronounced decrease in pH that can occur in an occluded cell, particularly when the alloy contains high concentrations of chromium and molybdenum. They also showed that migration of chloride ions into the solution in the pit can result in a 7-12-fold increase in concentration, and that the potential in the pit is in the active region. 

In an interesting study, phthalocyanine complexes containing four anthraquinone nuclei (5.34) were synthesised and evaluated as potential vat dyes and pigments [18]. Anthraquinone-1,2-dicarbonitrile or the corresponding dicarboxylic anhydride was reacted with a transition-metal salt, namely vanadium, chromium, iron, cobalt, nickel, copper, tin, platinum or lead (Scheme 5.6). Substituted analogues were also prepared from amino, chloro or nitro derivatives of anthraquinone-l,2-dicarboxylic anhydride. 

Primary separation occurs in the leaching procedure, where the metals copper, zinc, and nickel are dissolved as metal ammonium chlorides or chloro complexes, while iron and chromium remain in the solid residue as hydroxides. 

Chloro-5-thiophenethiol, 50,106 3a-Cholestanol, 50, IS Chromium(II)-en perchlorate, 52, 62 Chromium(II) salts, standardization procedure for solutions, 52, 64 Chromium trioxide-pyridine complex, 52,5... 

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