Gallium trichloride

Research in the organometallic and hydride chemistry of gallium is hampered by the absence of a convenient, reliable preparation of gallium trichloride, which is the common starting material in most preparations. 

The following preparation of gallium trichloride is applicable to both large- and small-scale reactions.4 Gallium trichloride is produced quantitatively and in high purity. Directions for the manipulation of this air-sensitive compound on the bench top or in a dry box are included. 

The desired quantity (1-100 g) of liquid gallium is poured into the apparatus through the 50-mm O-ring joint. The apparatus is reassembled and 

Analysis was performed by hydrolyzing a sample and then using edta (ethylenediaminetetraacetic acid) analysis for gallium6 and a Volhard procedure for chlorine. Anal. Calcd. for GaCl3 Ga, 39.6 Cl, 60.40. Found Ga, 39.3 Cl, 60.4. 

Gallium trichloride is a solid (mp 78-79°) which reacts with air. It is soluble in both hydrocarbons and ether-type solvents. Both the solid compound and its solutions can be stored in a waterfree environment for relatively long periods. Gallium trichloride undergoes typical metathetical displacement of one, two, or all three chlorine atoms in reactions with one, two, or three molar equivalents of an alkyllithium compound, respectively 4 

Submitted bt W. C. Johnson and Caleb A. Haskew Checked bt Fbederic B. Dutton t 

Gallium trichloride, GaCl3, may be prepared by the direct combination of the elements at slightly elevated temperatures.1 Unlike indium, which forms the dichloride by reaction with hydrogen chloride gas,2 gallium forms the trichloride. This method yields pure gallium trichloride and, in addition, eliminates the use of chlorine which is often objectionable. 

Hydrogen chloride (see synthesis 52) is dried by passage through a train of wash bottles containing concentrated sulfuric acid and a 30-in. drying tower filled with calcium chloride. Pure metallic gallium is obtained by the elec- 

The gallium (1 to 2 g.) is weighed into a porcelain boat, and the latter inserted into a pyrex tube 50 cm. in length and 2 cm. in diameter. A portion of this tube is surrounded by a small resistance furnace the temperature of which is controlled by an outside rheostat. After the air in the apparatus has been displaced by hydrogen chloride, the temperature of the furnace is allowed to rise slowly to 200°C. This temperature is maintained until all the gallium has disappeared from the boat. Reaction proceeds slowly at a temperature as low as 75°C., but the higher temperature is desirable because of the sublimation of the chloride to the cooler parts of the pyrex tube. Accordingly, a clean surface of the metal is always exposed. 

Gallium trichloride is a white crystalline solid melting at 76°C. It is readily sublimed in vacuo below its melting point. It is exceedingly hygroscopic and is readily hydrolyzed in an aqueous medium. 

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Complex Formation. B-Ttichlorobora2iQe was reported to readily form crystalline adducts of uncertain stmcture with pyridine (131). The Lewis acids aluminum tribromide or gallium trichloride form 1 1 adducts with hexamethylbota2iQe (eq. 36) ia which the metal atom coordinates with a nitrogen with loss of planarity of the ring (132,133). 

Gallium and Gallium Compounds, 71 Gallium trichloride, 71 Galvanoquimica Mexicana SA de C.V., 193 Gamma HCH, 71 Gasoline, 71... 

Gallium tribromide, 72 356 Gallium trichloride, 72 356 Gallium trihalides, 72 356, 357-358 Gallium triiodide, 72 356 Gallopamil, 5 121-122 molecular formula and structure, 5 119t Galvanic corrosion, 7 804-806 as failure mechanism, 26 983 in industrial water treatment,... 

Naphthalene-based bifunctional Lewis acids that involve boron and a heavier group 13 element have also been prepared starting from the boron/tin derivative 30 (Scheme 15). Thus, the transmetalation reaction of 30 with gallium trichloride or indium trichloride in tetrahydrofuran (THF) results in high yields of l-(dichlorogallium)-8-(dimesitylboron)naphthalenediyl 35 and l-(dichloroindium)-8-(dimesitylboron)... 

Aluminum chloride or gallium trichloride (82MI3) or trimethylaluminum (82MI2) convert 4-methylbenzene-1,2-dithiol into the radical cation of 2,7-dipiethylthianthrene the rather unlikely loss of hydrogen sulfide in a step, 95 96, was imputed (Scheme 16). 

Usugi, S. Yorimitsu, H. Shinokubo, H. Oshima, K. Disulfidation of Alkynes and Alkenes with Gallium Trichloride. Org. Lett. 2004, 6, 601-603. 

The benzobisazole family of rigid-rod polymers is soluble in acidic solvents such as PPA, methanesulfonic acid, chlorosulfonic acid, 100% sulfuric acid and Lewis acid salts such as antimony trichloride and bismuth trichloride. More recently, PBZT has been reported [22] to form liquid crystalline solutions in nitromethane containing aluminum trichloride or gallium trichloride. Since the glass transition temperature of these materials is above their decomposition temperature, they must be processed from solution. 

Diethyl ether and toluene (both BDH, GPR grade) are dried and freed of dissolved molecular oxygen by distillation under nitrogen from a solution of the solvent and sodium benzophenone. Anhydrous indium trichloride (Aldrich) and an ethereal solution of methyllithium (Aldrich) are used as supplied dppe (Fluorochem) is also used as supplied. Anhydrous gallium trichloride (Aldrich) is sublimed before use. 

The reaction to form the trimethylgallium adduct is similar. The only difference in procedure is that, before adding dry diethyl ether (25 mL) to anhydrous gallium trichloride (4.9 g, 27.8 mmol), the flask containing the gallium trichloride is cooled in an ice/water bath or the exothermic reaction between these reagents will lead to substantial smoking in the flask. 

GaCl3 gallium trichloride or gallium(III) chloride IC13 iodine trichloride or iodine(III) chloride S03 sulphur trioxide or sulphur(VI) oxide... 

The use of etherate of boron trifluoride is well known for these syntheses [11]. Etherate of gallium trichloride is also applied (3.103) [199] ... 

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