Zinc compounds ZnCl2

In the home lab, you can make hydrogen by adding strips of zinc from a flashlight battery to hydrochloric acid which consists of hydrogen (H) and another gas called chlorine (Cl). The zinc forms a compound (ZnCl2) with the chlorine and sets the hydrogen free (II ). 

In this reaction, the element zinc (Zn) takes the place of hydrogen in the compound hydrochloric acid (HCl). When the zinc and hydrogen switch places, the products are zinc chloride (ZnCl2) and hydrogen gas (H2). 

Another useful compound is zinc chloride (ZnCl2), which is used as a wood preservative, as a soldering fluid to remove oxides from metallic surfaces, and in the production of parchment paper. 

Uses Zinc (Zn) is one of the most common elements in the Earth s crust. Metal zinc was first produced in India and China during the Middle Ages. Industrially important compounds of zinc are zinc chloride (ZnCl2), zinc oxide (ZnO), zinc stearate (Zn (Ci6H3502)2), and zinc sulfide (sphalerite, ZnS). It is found in air, soil, and water, and is present in all foods. Pure zinc is a bluish-white shiny metal. Zinc has many commercial uses, as coatings to prevent rust, in dry cell batteries, and mixed with other metals to make alloys like brass and bronze. Zinc combines with other elements to form zinc compounds. Zinc compounds are widely used in industry to make paint, rubber, dye, wood preservatives, and ointments.109-112... 

Most single displacement reactions involve one metal displacing another metal from a compound. In the following equation, magnesium metal replaces the zinc in ZnCl2, thereby liberating zinc as the free metal. 

Inorganic compounds can also act as radical initiators. Zinc chloride (ZnCl2) has been used to initiate radical reactions at —78 °C. In following case (Scheme 19), zinc chloride acts as a radical initiator as well as a chelating agent. 

Acridines are an important structural feature of many natural products and medicinally important compounds. They can be produced in a straightforward manner by a Friedel-Crafts reaction, the Bernthsen acridine synthesis, 1 9 which couples diaryl amines (such as diphenylamine) with a carboxylic acid (such as benzoic acid) in the presence of a Lewis acid (zinc chloride, ZnCl2, is a typical reagent). Heating to 260°C (10 h) gave a 48% yield of acridine 317.1 9 ... 

Contamination has been reported of ArgZn by Ar2Mg when prepared from ZnCl2 and ArMgX. The u.v.-visible spectra of (RCgH4CH2)2 zinc compounds (R=H, o-F, o-C, o-Bt, o-Me, and p-Me) and of their bipy adducts have been obtained. Compounds (14, M=Zn or Cd) have dramatic thermal and chemical stability e.g., (14, M=Zn) can be steam distilled and it does not react with... 

Pure pyridine may be prepared from technical coal-tar pyridine in the following manner. The technical pyridine is first dried over solid sodium hydroxide, distilled through an efficient fractionating column, and the fraction, b.p. 114 116° collected. Four hundred ml. of the redistilled p)rridine are added to a reagent prepared by dissolving 340 g. of anhydrous zinc chloride in a mixture of 210 ml. of concentrated hydrochloric acid and 1 litre of absolute ethyl alcohol. A crystalline precipitate of an addition compound (probable composition 2C5H5N,ZnCl2,HCl ) separates and some heat is evolved. When cold, this is collected by suction filtration and washed with a little absolute ethyl alcohol. The yield is about 680 g. It is recrystaUised from absolute ethyl alcohol to a constant m.p. (151-8°). The base is liberated by the addition of excess of concentrated... 

The pyrazole phosphazine ligand, hexakis(3,5-dimethylpyrazolyl)cyclotriphosphazene (16) forms a dizinc complex, that has been structurally characterized, and the analogous copper zinc complex.158 Two ZnCl2 units are coordinated, one distorted tetrahedral and one distorted trigonal-bipyramidal, separated by 7.51 A. Cu1 and ZnCl2 can also be coordinated giving a heteronuclear compound with a Zn Cu separation of 6.798 A. 

As expected based on the 3d10 4s2 configuration, zinc routinely forms +2 compounds, and all of the halides having the formula ZnX2 are known. Anhydrous ZnCl2, which has applications in the textile industry, can be prepared as shown by the following equation ... 

Evaporation of a solution produced by dissolving Zn in aqueous hydrochloric acid gives ZnCl2.2H20 as the solid product. Heating this compound does not result in the formation of anhydrous zinc chloride because of the reaction... 

The synthesis and stmctnral characterization of a series of spirocyclic organozincates containing two five- or six-membered metallacycles in which zinc is the central spiro atom, is shown in Scheme 1. Compound 8a was prepared via an elegant one-pot synthesis, starting from 1,5-dichloropentane, ZnCl2 and a lithium/sodinm alloy (1% sodinm) in diethyl ether as a solvent (eqnation 4 in Scheme 1). Snbseqnent treatment of a soln-tion of 8a with TMEDA afforded the corresponding TMEDA complex 8b of which the structnre in the solid state was unambiguously established by an X-ray crystal structnre determination. 

Reaction of two equivalents of 2-[(dimethylamino)methyl]ferrocenyUithium with ZnCl2 affords the corresponding diorganozinc compound (68) in which two 2-[(dimethylamino) methyl]ferrocenyl ligands are C,Af-chelate bonded to zinc. Due to the chirality of the bidentate ligands 68 exists in two diastereoisomeric forms. Indeed, in solution a meso one and an S,S)/ R,R) enantiomeric parr in a 1 4 ratio were observed by H and C NMR spectroscopy. However, it is only the S,S)/ R,R) enantiomeric pair that preferentially crystallizes from solution. An X-ray crystallographic study of such crystals afforded the structure of (R,R)/(S,S)-6S in the solid state (Figure 35). 

Compound 69 contains two C,Af-chelate-bonded iminophosphorane ligands and was obtained from the reaction of ZnCl2 with two equivalents of the corresponding ortho-hthiated derivative. An X-ray structure determination of 69 revealed a molecular geometry as shown in Figure 36. Because the zinc atom is located on a crystallographic inversion centre, the two C,Af-chelate-bonded hgands are symmetry-related. 

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