II Chloride

Anhydrous iron(II) chloride has been prepared by passing hydrogen chloride over iron, by reducing iron(III) chloride with hydrogen, and by dehydrating one of the hydrates of iron(II) chloride. A new procedure is outlined here.1,2 

Two hundred and twenty-five grams (2 mols) of chlorobenzene and 162 g. (1 mol) of C.P. anhydrous iron(III) chloride are added to a three-necked, round-bottomed flask equipped with a thermometer, efficient paddle stirrer, and condenser. Arrangements are made to pass the hydrogen chloride which is evolved during the reaction through a 

DICHLORO (DI-2-PYRID YLAMINE)COPPER (II) AND BIS(DI-2-PYRIDYLAMINE)COPPER(II) CHLORIDE 

Anhydrous copper(II) chloride is first prepared by heating the 2-hydrate at 125° for 12 hours. A solution of 

Both complexes precipitate as extremely minute crystals. The olive-green mono(dipyridylamine) complex is stable in air up to a temperature of 290°, whereas the bis(dipyridyl-amine) complex is stable up to 235°. Both compounds are very slightly soluble in acetone, ethyl ether, benzene, chloroform, and carbon tetrachloride. The mono(dipyri- 

The very slightly soluble mono (dipyridylamine) complex reacts with excess dipyridylamine in methanol or ethanol to give the soluble bis(dipyridylamine) complex according to the equation 

Molybdenum (II) bromide was prepared first by Blomstrand8 by passing bromine vapor over heated molybdenum. Lindner et al.9 then improved the method by using bromine vapor diluted with nitrogen. More recently Sheldon10 converted molybdenum(II) chloride to the bromide by fusion with lithium bromide. Like the chloride, molybdenum(II) bromide is usually an amorphous powder however, crystalline samples have been prepared by disproportionation of molybdenum (III) bromide under vacuum at 600°C.1 Our method is substantially that of Sheldon and consists of heating an intimate mixture of molybdenum (II) chloride and a large excess of lithium bromide under vacuum. The crude product that results is dissolved in dilute sodium hydroxide and precipitated in pure form with concentrated hydrobromic acid. 

The reaction tube (see Fig. 16) is a Vycor tube about 125 cm. long and 2.5 cm. in diameter. Both ends of the tube are fitted with male ground-glass joints for connection to stopcocks. The tube is dried thoroughly by heating while a slow stream of nitrogen is passed through it. 

An intimate mixture of 50 g. of molybdenum(V) chloride with 150 g. of molybdenum powder (mesh size 100) prepared under anhydrous conditions is distributed uniformly along the length of the tube. Two glass-wool plugs (A and B in the figure) are placed about 15 cm. from the joints at the ends of the tube to 

The ligand, 3.22 g. (0.020 mole) of 2,2 -iminobis(acetamid-O-xime), is dissolved in the minimum amount of water at room temperature in a 50-ml. beaker. To this solution is added a concentrated aqueous solution of 2.38 g. (0.010 mole) of nickel-(II) chloride 6-hydrate. Violet crystals form almost immediately, and are filtered off after about 7 hours, using a 30-ml. medium-porosity sintered-glass crucible. The crystals are washed once with ice-cold water, twice with absolute ethanol, twice with dry ether, and air-dried. The yield is 3.80 g. [84%, based on the nickel(II) chloride]. Anal. Calcd. for Ni(C8H22Nio04)Cl2 Ni, 13.00 C, 21.28 H, 4.92 N, 31.14 Cl, 15.70. Found Ni, 12.94 C, 21.91 H, 4.55 N, 31.75 Cl, 16.72. 

0031-mole) quantity of manganese(II) chloride 4-hydrate is dissolved in 6 ml. of absolute ethanol. This solu- 

Checked by Therald Moeller, Paul G. Gordon, and Fred McCullough, Jr.  

Vanadium(II) chloride is formed when a mixture of vanadium (IV) chloride and hydrogen is passed through a hot tube1 and by the reduction of vanadium(III) chloride with hydrogen.2 It is also produced by the thermal disproportionation of vanadium(III) chloride3,4 into the nonvolatile dichloride and the volatile tetrachloride. 

The method adopted for the preparation of vanadium (II) chloride is the reduction of the trichloride by hydrogen at temperatures not exceeding 675°. 

About 30 g. of vanadium(III) chloride (0.19 mol) is placed at the middle of a pyrex tube 60 cm. long and 25 mm. in diameter, through which dry nitrogen is passing. This operation can be performed without moisture coming in contact with the salt with the apparatus described in syn- 

Vanadium(II) chloride forms apple-green leaflets which behave toward water somewhat like chromium (II) chloride.5 They may be wetted slowly by water. The salt is soluble in water, forming the violet hydrated vanadium(II) ion. This ion is readily oxidized by the oxygen of the air and by hydrogen ion. The salt dissolves in alcohol and ether, the resulting solutions being respectively blue and greenish yellow.3 

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Lead II) chloride, PbCl2. Insoluble cold water, sparingly soluble hot. Matlockite is PbFCl. PbCL forms many complex chlorides and also basic chlorides. Cassel yellow (approx. PbCl2 7PbO) is prepared by fusion of the constituents and is used as a pigment. 

Mercury(II) chloride, HgC, corrosive sublimate, m.p. 280 C, b.p. 302"C. Essentially covalent material (Hg plus CL Hg plus aqua regia). Forms complex halide ions, e.g. (HgCU) (HgCL)" in excess HCl and forms complexes. Very poisonous. 

Vanadium II) chloride, VCI2. Green solid formed VCI4. plus H2. 

Wadsd I 1968 Heats of vaporization of organic compounds II. Chlorides, bromides and iodides Acta Chem. Scand. 22 2438... 

Lead reacts slowly with hot concentrated hydrochloric acid since the lead II) chloride dissolves in an excess of the hot hydrochloric acid to form the acid H,[Pb"CI ] ... 

Ethene can add on to certain metal salts it is believed that the extra electrons of the double bond can be donated to some extent an example is the compound PtCl2-C2H4 formed with platinum(II) chloride which has the structure... 

Lead(IV) oxide is found to have a considerable oxidising power, again indicating that the oxidation state +2 is generally more stable for lead than oxidation state +4. Concentrated hydrochloric acid, for example, reacts with PbO at room temperature to form lead(II) chloride and chlorine ... 

Germanium forms divalent compounds with all the halogens. Germaniunil 1) chloride can be prepared by passing the vapour of germanium(IV) chloride (see below) over heated germanium. The reaction is reversible and disproportionation of germanium(II) chloride is complete at about 720 K at atmospheric pressure ... 

Germanium(II) chloride is hydrolysed by water the reaction can be represented as... 

This chloride is prepared by dissolving tin in concentrated hydrochloric acid on cooling, the solution deposits crystals of hydrated tin(II) chloride. SnClj. 2H2O ("tin salt ). The anhydrous chloride is prepared by heating tin in a current of hydrogen chloride ... 

A solution of tin(II) chloride is a reducing agent. Hence it reduces ... 

Tin(II) chloride is slowly oxidised in air. but keeping a piece of tin metal in the solution prevents this. 

Hence, if chlorine is passed into a cold suspension (in hydrochloric acid) of lead(II) chloride, lead(IV) chloride is formed. Addition of ammonium chloride gives the complex salt ammonium hexachloro-plumbate(lV) as a yellow precipitate ... 

In presence of hydrochloric acid, tin(II) in aqueous solution (1) is precipitated by hydrogen sulphide as brown SnS, and (2) will reduce mercury(II) chloride first to mercury(I) chloride (white precipitate) and then to metallic mercury. 

Tin(IV) in aqueous acid gives a yellow precipitate with hydrogen sulphide, and no reaction with mercury(II) chloride. 

Lead(II) in aqueous solution gives on addition of the appropriate anion (1) a white precipitate of lead(II) chloride, (2) a yellow precipitate of lead(II) chromate, and (3) a yellow precipitate of lead(II) iodide which dissolves on heating and reappears on cooling in the form of glistening spangles . 

Anhydrous hydrogen fluoride (as distinct from an aqueous solution of hydrofluoric acid) does not attack silica or glass. It reacts with metals to give fluorides, for example with heated iron the anhydrous iron(II) fluoride is formed the same product is obtained by displacement of chlorine from iron(II) chloride ... 

The higher iodides, however, tend to be unstable and decomposition occurs to the lower iodide (PI5 -> PI3). Anhydrous chlorides and bromides of some metals may also be prepared by the action of acetyl (ethanoyl) halide on the hydrated ethanoate (acetate) in benzene, for example cobalt(II) and nickel(II) chlorides ... 

Sulphur dichloride oxide (thionyl chloride) on the hydrated chloride can also be used to produce the anhydrous chloride in certain cases, for example copper(II) chloride and chromium(III) chloride ... 

Addition of mercury(II) chloride solution to a solution of an iodide gives a scarlet precipitate of mercury(II) iodide, soluble in excess of iodide ... 

Titanium forms dihalides TiXj, for example titanium(II) chloride, formed by heating titanium metal and the tetrachloride to about 1200 K. TiCl2 is a black solid, which disproportionates on standing to TiCl4 + Ti. Since it reduces water to hydrogen, there is no aqueous chemistry for titanium(II). A solid oxide TiO is known. 

Cobalt II) halides can be obtained by direct combination of the elements, or by dehydration of their hydrates. Anhydrous cobalt(II) chloride is blue, and the solid contains octahedrally-coordinated cobalt the hydrated salt C0CI2. bHjO is pink, with each cobalt surrounded by four water molecules and two chloride ions in a distorted octahedron. 

These are of two general kinds octahedral, pink complexes and tetrahedral, blue complexes. If cobalt(II) chloride is dissolved in aqueous solution, the predominant species is the hexaaquo-ion [ColHjO) ] (pink). If this solution is heated, it becomes blue, and the same effect is observed if chloride ion is added in excess. This colour change is associated with the change... 

Nickel forms yellow anhydrous halides NiXjlX = F. Cl. Br) and a black iodide Nil2 all these halides are made by direct combination of the elements, and the chloride by reaction of sulphur dichloride oxide with the hydrated salt. All dissolve in water to give green solutions from which the hydrates can be crystallised the solutions contain the ion [NifHjOls], and the chloride crystallises as NiCl2.6H2O, nickel(II) chloride hexahydrate. 

By warming either copper(I) oxide or a mixture of copper(II) chloride and copper with concentrated hydrochloric acid, until a deep brown solution is formed ... 

By the reduction of copper(II) chloride or a mixed solution of copper(II) sulphate and common salt by sulphur dioxide. 

When cobalt(II) chloride was dissolved in water, a pink solution A was formed. The addition of concentrated hydrochloric acid to A gave a blue solution B. If solution A was treated with concentrated ammonia solution a blue-green precipitate was formed upon addition of further ammonia solution followed by the passage of air through the mixture, an orange-red solution C was produced. 

Mercury compounds (for example mercury(II) chloride) are used in medicine because of their antiseptic character. The artificial red mercury(Il) sulphide is the artist s vermilion . Mercury(II) sulphate is a catalyst in the manufacture of ethanal from ethyne ... 

The aqueous solution has a low conductivity, indicating that mercury(II) chloride dissolves essentially as molecules Cl—Hg—Cl and these linear molecules are found in the solid and vapour. A solution of mercury(II) chloride is readily reduced, for example by tin(ll) chloride, to give first white insoluble mercury(I) chloride and then a black metallic deposit of mercury, The complexes formed from mercury(II) chloride are considered below. 

In a lOOmL round-bottomed flask fitted with a magnetic stirrer is placed a mixture of palladium (II) chloride (89mg, O.Smmol), p-benzoquinone (5.94g, 55mmol) and 7 1 dimethylformamide/water (20mL). To the solution, t-decene [substitute safrole for this compound) (7.0g, 50mmc4) is added in 10 min and the mixture is stirred at room temperature for 7h. The solution is poured into cold 3 normal hydrochloric acid (lOOmL) and extracted with 5 portions of ether. The extracts are combined and washed with three portions of 10% aqueous sodium hydroxide solution and a portion of brine, and then dried After removal of the solvent, the residue is distilled to give 2-decanone [P2P] yield 6.1g (78%). 

Example 68 Add. 1 mole of 3-(3,4-methylenedioxyphenyl) propylene,. 25 mole of methyl nitrite,, 5L of methanol, 36g of water,. 006 mole of bisfbenzonitrile) palladium (II) chloride as a catalyst to a flask. Stir magnetically for 1.5 hours at 25C. The conversion of the starting material was 100%, the yield of MDP-2-P was 88%. 

In connection with mechanistic studies on the Wacker reaction, the transmetallation of ri-ethoxy- and /3-hydroxyethylmercury(II) chloride with PdCB has been carried out, giving ethyl vinyl ether and acetaldehyde[366]. The reaction proceeds by the formation of ri-ethoxy- and /3-hydroxyethylpalladium chlorides (401), which decompose as soon as they are formed. 

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