Manganese thiocyanates

According to X-ray data, 2,5-diamino-l,3,4-triazole retains its diamino form in the heterovalent cobalt complex 375 (91IC4858) and in the polymeric complex with manganese thiocyanate (93ICA53). 

The observation of a strong infrared absorption at below 2,000 cm for the dinuclear complex of (185) incorporating manganese thiocyanate was taken as indicating that rare (single atom) N-bound NCS bridges occur in this manganese(II) species." " ... 

Determination of copper as copper(I) thiocyanate Discussion. This is an excellent method, since most thiocyanates of other metals are soluble. Separation may thus be effected from bismuth, cadmium, arsenic, antimony, tin, iron, nickel, cobalt, manganese, and zinc. The addition of 2-3 g of tartaric acid is desirable for the prevention of hydrolysis when bismuth, antimony, or tin is present. Excessive amounts of ammonium salts or of the thiocyanate precipitant should be absent, as should also oxidising agents the solution should only be slightly acidic, since the solubility of the precipitate increases with decreasing pH. Lead, mercury, the precious metals, selenium, and tellurium interfere and contaminate the precipitate. 

Intimate mixtures of chlorates, bromates or iodates of barium, cadmium, calcium, magnesium, potassium, sodium or zinc, with finely divided aluminium, arsenic, copper carbon, phosphorus, sulfur hydrides of alkali- and alkaline earth-metals sulfides of antimony, arsenic, copper or tin metal cyanides, thiocyanates or impure manganese dioxide may react violently or explosively, either spontaneously (especially in presence of moisture) or on initiation by heat, friction, impact, sparks or addition of sulfuric acid [1], Mixtures of sodium or potassium chlorate with sulfur or phosphorus are rated as being exceptionally dangerous on frictional initiation. 

Magnesium nitrate, Tin(ll) fluoride, 4693 Manganese(lV) oxide, Calcium hydride, 4705 Molybdenum(VI) oxide, Graphite, 4717 Nitric acid, Formaldehyde, 4436 Nitric acid, Formic acid, 4436 Nitric acid, Formic acid. Urea, 4436 Nitric acid, Metal thiocyanate, 4436 Oxalic acid, Urea, 0725 Ozone, Acetylene, 4846... 

Arsenic triiodide also dissolves, the saturated solution at 15° C. having density 3-661. Other soluble halides are potassium bromide, anhydrous ferric and aluminium chlorides 6 and tetramethyl ammonium iodide but the iodides of rubidium, cadmium, manganese and cobalt, also mercuric and stannic iodides, and cobalt and stannic bromides, are insoluble or only very slightly soluble in arsenic tribromide. The liquid also dissolves phosphoryl bromide and, very slightly, ammonium thiocyanate. In the mixed solutions of halides, the components may react chemically (cf. p. 106), but such is not always the case for example, with antimony tribromide a continuous series of solid solutions is formed.7... 

Gas chromatography has, of course, been used extensively in the analysis of many types of organic compounds with boiling points up to about 250°C, also to the analysis of organic compounds of lead, mercury, selenium, tin, manganese and silicon. Derivitisation of these compounds to produce compounds sufficiently volatile to be amenable to gas chromatography is frequently practised. Gas chromatography has also been applied to the determination of arsenic, antimony, selenium, tin, beryllium and aluminium and the common anions such as sulphate, nitrate, phosphate, sulphide, cyanide and thiocyanate. 

Five-hundredths mole of a manganese(II), iron(II),t cobalt(II), nickel(II), copper(II), or zinc(II) salt is dissolved in 300 ml. of distilled water containing 20 ml. of pyridine. To this solution is added slowly with stirring a solution of 8.00 g. of ammonium thiocyanate in 100 ml. of distilled water, and the resulting mixture is allowed to stand in an ice bath until precipitation appears complete (ca. an hour). The precipitate is collected on an 8-cm. Buchner funnel and is washed with three 10-ml. portions of an ethanol-pyridine (9 1) solution. The product is air-dried for not longer than 10 minutes. It is powdered and then dried in a desiccator over potassium hydroxide until constant weight has been attained (ca. 24 hours). In the cases of copper(II) and zinc(II), the dipyridine compound is obtained. Details of separate syntheses are given in Table I. 

The advantage of this explanation of thiocyanate coordination is that it does allow a description that fits both classes a and b metal complexes, although there are some examples that do not fit. It is not clear Avhy in Rh(PPhg)2L(CNS) the N isomer should be obtained for L = pip, and the S isomer for L = MeCN (35). Manganese(I) has to be treated as a class a acid, the same approach as is used for it to fit with... 

SAFETY PROFILE Poison by ingestion and intraperitoneal routes. A trace mineral added to animal feeds. Potentially explosive reaction with charcoal + ozone, metals (e.g., powdered aluminum, copper), arsenic carbon, phosphoms, sulfur, alkali metal hydrides, alkaline earth metal hydrides, antimony sulfide, arsenic sulfide, copper sulfide, tin sulfide, metal cyanides, metal thiocyanates, manganese dioxide, phosphorus. Violent reaction with organic matter. When heated to decomposition it emits very toxic fumes of I and K2O. See also lODATES. 

Bautista and Hard (B8) made a comparative study of the extractability of. several of the first-transition metals from thiocyanate solutions using methyl isobutyl ketone as the organic solvent. The transition metals readily extracted were scandium (III), iron (III), and cobalt (II) while chromium (II) and manganese (II) were not. The principal extractable species were found to be the neutral scandium and iron trithiocyanate complexes, while the extractable cobalt complex was the negatively charged tetrathiocyanate radial Co(SCN)4 . The distribution ratio for scandium, iron, and cobalt decreased with increase in metal ion concentrar tion but increased with increasing ionic strength of the solutions. 

The isomeric 1-suhstituted imidazole-5-carboxylates are made by cyclization of 3-amino-2-alkylaminopropanoic acids with triethyl orthoformate followed by active manganese dioxide oxidation of the imidazoline product (see Section 3.1.1), or from IV-substituted glycine esters, which are formylated, converted into the enolates and then condensed with potassium thiocyanate... 

The thiocyanate method has been used for determining cobalt in vitamin B12 [94], steel [24,94], and nickel [25]. Cobalt present in considerable amounts in alloys with aluminium, nickel, chromium, manganese, copper, and iron was determined by the differential spectrophotometric analysis [95]. 

Potassium persulfate-Silver nitrate [1, 954, before Potassium thiocyanate]. This combination is about as satisfactory as Attenburrow manganese dioxide for the oxidation of 5-hydroxyuracil to uracil-5-aldehyde.1... 

Manganese(II) thiocyanate (0.05 mole, 8.55 g) is dissolved in 100 mL of water. Then 1,2,4-triazole (0.1 mole 6.91 g), dissolved in 50 mL of water, is added. A few drops of concentrated nitric acid are added and the solution is heated to boiling, cooled immediately to room temperature and stored for several days in a desiccator above phosphorus pentoxide. The yield of the product, recovered by Filtration, washed with water and dried under vacuum is —12 g or about 75%. The crystals have the shape of flat rhombi, almost squares, with a thickness of about one-fifth of the largest diameter. Crystal diameters may vary from 1-10 mm depending upon the preparative technique. Crystallization of this compound occurs more slowly than for the compounds containing other metals. 

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