Titanium III Chloride

The apparatus for the preparation is assembled as shown in Fig. 7. Standard ground-glass joints are used through- 

The purification is effected by passing the hydrogen through a porcelain tube containing copper turnings, which is heated in a tubular electric oven to about 800°, and next 

When all the hydrogen has been driven out by nitrogen, the reflux condenser is quickly replaced by a downward con- 

During 8 to 10 hours operation, 300 to 350 g. of titanium-(III) chloride may be prepared. The yield on the basis of TiCb not recovered is 80-85%. On the basis of total titanium(IV) chloride, the yield is 30 to 40% (Sherfey obtained 10%). 

Submitted by Veba Dobon Checked by Duwabd SHBiVEBt 

---

When titanium dissolves in dilute hydrochloric acid, a violet solution containing titanium(III) ions is formed. This solution rapidly decolorises acidified aqueous potassium permanganate at room temperature. Titanium(IV) chloride is a colourless covalent liquid completely hydrolysed by water. Titanium(III) chloride forms hydrated titanium(III) ions in water and disproportionates when heated in a vacuum. 

The Stock Oxidation-Number System. Stock sought to correct many nomenclature difficulties by introducing Roman numerals in parentheses to indicate the state(s) of oxidation, eg, titanium(II) chloride for TiCl2, iron(II) oxide for FeO, titanium(III) chloride for TiCl, iron(III) oxide for Fe203, titanium(IV) chloride for TiCl, and iron(II,III) oxide for Fe O. In this system, only the termination -ate is used for anions, followed by Roman numerals in parentheses. Examples are potassium manganate(IV) for K2Mn02, potassium tetrachloroplatinate(II) for K PtCl, and sodium hexacyanoferrate(III) for Na3Fe(CN)3. Thus a set of prefixes and terminations becomes uimecessary. 

Note Sulfuric acid (4%) can also be employed in place of hydrochloric acid [3]. If ammoniacal mobile phases are employed the ammonia should be removed completely (e.g. heat to 105 °C for 10 min) before dipping or spraying otherwise background discoloration can occur. The addition of titanium(III) chloride to the reagent allows also the staining of aromatic nitro compounds [6]. 

It is possible to titrate two substances by the same titrant provided that the standard potentials of the substances being titrated, and their oxidation or reduction products, differ by about 0.2 V. Stepwise titration curves are obtained in the titration of mixtures or of substances having several oxidation states. Thus the titration of a solution containing Cr(VI), Fe(III) and V(V) by an acid titanium(III) chloride solution is an example of such a mixture in the first step Cr(VI) is reduced to Cr(III) and V(V) to V(IV) in the second step Fe(III) is reduced to Fe(II) in the third step V(IV) is reduced to V(III) chromium is evaluated by difference of the volumes of titrant used in the first and third steps. Another example is the titration of a mixture of Fe(II) and V(IV) sulphates with Ce(IV) sulphate in dilute sulphuric acid in the first step Fe(II) is oxidised to Fe(III) and in the second jump V(IV) is oxidised to V(V) the latter change is accelerated by heating the solution after oxidation of the Fe(II) ion is complete. The titration of a substance having several oxidation states is exemplified by the stepwise reduction by acid chromium(II) chloride of Cu(II) ion to the Cu(I) state and then to the metal. 

With a more powerful reductant, e.g. titanium(III) chloride, the iodate is reduced to iodide ... 

The conversion of secondary a-nitro sulfones (257) upon treatment with 20% aqueous titanium(III) chloride in THF to nitriles has been reported (equation 157)146. 

The specific detection of aromatic nitro compounds is a second example. These can be converted by reduction to primary amines, which are then diazotized and coupled to yield azo dyes (cf. reagent sequence Titanium(III) chloride — Bratton-Marshall reagent ). Sodium nitrite —naphthol reagent, diazotized sulfanilic acid and other reagents specific for amino groups (e.g. ninhydrin, fluorescamine, DOOB, NBD chloride [9]) can also be used in the second stage of the reaction (Fig. 21). 

Spray solution 1 Dissolve 0.5 g titanium(III) chloride in 100 ml N hydrochloric acid. 

In a first step oxidized aromatic amines are reduced with titanium(III) chloride in glacial acetic acid solution and then condensed to a colored Schiff s base with 4-(dimethylamino)-benzaldehyde (cf. Chapter 2). 

The plate should be heated as rapidly and as evenly as possible after the first spraying step this is best done on a thick preheated aluminium plate in a drying cupboard equipped with ventilation allowing the nitric acid vapors to be removed using a water pump vacuum. Sodium dithionite is better than titanium(III) chloride or tin(II) chloride for the reduction of the nitro derivatives of amitrityline and nortriptyline. 

Spray solution 2 Dilute 4 ml of a solution of 15 g titanium(III) chloride in 100 ml hydrochloric acid (4 l o) to 20 ml with methanol. This solution is only stable for about 1 h and should, therefore, always be made up fresh. 

Dipping solution 1 Make 10 ml titanium(III) chloride solution (c = 151 o in 10% hydrochloric acid) up to 50 ml with acetone [1]. 

Titanium(III) chloride (particularly in slightly alkaline medium) reduces the p-nitro groups of the thiophosphate insecticides to amino groups, which are then reacted with nitrite in acid mediiun in a second step to yield a diazonium compound as intermediate. This is then coupled to N-(l-naphthyl)-ethylenediamine dihydrochloride to yield an azo dye [3]. In the case of benzodiazepines the first reaction step includes an additional acid hydrolysis to the corresponding benzophenone derivative [2]. 

The dinitrophenyl derivatives are reduced by titanium(III) chloride in acidic medium in the first step of the reaction to the corresponding aromatic amines these are then diazotized and coupled with N-(l-naphthyl)-ethylenediamine to yield an azo dye (cf. Fig. 21). 

Substances Titanium(III) chloride (15% in 10 percent hydrochloric acid)... 

Nitric Add/Sulfuric Add — Titanium(III) Chloride—Sodium Nitrite—... 

Titanium(III) Chloride — Nitrous Fumes—N-(l-Naphthyl)-ethylenediamine 117... 

---