Boron tribromide trichloride

The reaction is irreversible and can be used to synthesize aUphatic and aromatic esters. In addition, there are no complications involving water removal or azeotrope formation. Boron tribromide can be used ia place of boron trichloride, but the bromide has a stronger tendency to halogenate the alkyl group of the alcohol (26). Boron tritiuoride does not give the ester, but gives either a complex or dehydrated product. 

C21-0086. Boron trichloride is a gas, boron tribromide is a liquid, and boron triiodide is a solid. Explain this trend... 

The original method1 reported for the preparation of trichloroborazine involves the use of borazine. However, this procedure is not recommended because of the difficulty of preparing this heterocycle and its hydrolytic instability. More recently, this trichloroborazine has been prepared directly from ammonium chloride and boron trichloride at elevated temperatures with or without a solvent.2-8 Ammonium chloride may be replaced by a primary aliphatic or aromatic amine or its hydrochloride, and organodihaloboranes can be used in place of the boron trichloride to give the respective N- and B-substituted borazines.6 Boron tribromide has been used in analogous reactions to yield -B,/ , .B"-tribromoborazines.6... 

Bordetella pertussis Toxin Borer Sol Boroethane Boron Bromide Boron Chloride Boron Fluoride Boron Hydride Boron Tribromide Boron Trichloride Boron Trifluoride Botox... 

See also Borates Boric acid Sodium borates boron oxides, 4 246-249 boron oxides table,4 242t environmental concerns, 4 284—285 health and safety factors, 4 285-288 occurrence, 4 245—246 Boron perchlorates, 18 278 Boron phosphate, 4 242t, 283 Boron removal, from water, 14 418 Boron-stabilized carbanions, 13 660-661 Boron subhalides, 4 141 Boron suboxide, 4 242t Boron tribromide, 4 138 manufacture, 4 145—146 physical properties of, 4 139-140t, 325 reactions, 4 141 specifications, 4 147t uses of, 4 149 Boron trichloride, 4 138 manufacture, 4 145—146 physical properties of, 4 139-140t reactions, 4 141... 

Treating the oxide, trichloride, or metal with boron tribromide or boron triiodide has produced tribromides and triiodides for lanthanum (119). Presumably, treating the metal or the oxide with boron trichloride will produce the trichloride. 

Boron diiodophosphide, 0149 Boron tribromide, 0122 Boron trichloride, 0127 Boron trifluoride, 0129... 

Ammino-derivatives of Boron Salts—Derivatives of Boron Fluoride, Trichloride, Tribromide, Tri-iodide. 

Preparation of Boron Tribromide. (Perform the experiment in a fume cupboard ) Assemble a part of the apparatus shown in Fig. 112 beginning from vessel 3 without a gas-discharge tube. Put 54 g of aluminium tribromide and 13 g of potassium tetrafluoborate into reaction vessel 3 and close it. Carefully heat the vessel with the flame of a burner. Prepare and purify the boron tribromide in the same way as boron trichloride. 

The halides, GaQs, AlBrs, A1C13, and FeCl3, very probably also exist in dimeric form. With these halides, however, the complexation reaction with the azide is the fast step so that no square-root term is found in the kinetic equation. Arsenic trichloride, arsenic tribromide, phosphorus trichloride, and phosphorus pentachloride were without effect on the rate of decomposition of benzoyl azide. Finally, the authors have observed that the catalytic influence of boron tribromide was much higher than all the other halides. Its rate constant was estimated to be about 18 times larger than that for gallium chloride. 

Borane-Sodium borohydride, 42 Borane-Tetrahydrofuran, 42 Boron tribromide, 43 Boron trichloride, 43 Boron trifluoride, 44 Boron trifluoride etherate, 3, 6, 10, 13, 43, 82, 99, 193, 200, 211, 306, 308, 321, 322... 

Borane carbonyl BHjCO Borazine B3N3H Boron tribromide BBr Boron trichloride BClj Boron trifluoride BF Bromodiborane BjHsBr Diborane(6) B2H... 

The contaminants in commercial boron trichloride usually are HCI and COCI2, as well as oxychlorides which have some volatility. The oxyhalides are readily removed by one or two trap-to-trap distillations in a clean vacuum system. Most of the HCl can be removed by holding the BCI3 at — 78°C and pumping away the volatiles for a brief period (some BCI3 is sacrificed in the process). Phosgene, which may be detected by its gas-phase infrared absorption at 850 cm"1, is very difficult to remove. Liquid boron tribromide is generally supplied in sealed ampules. If it is straw colored, dibromine is a likely impurity, and this... 

Boron trichloride phosphorus tribromide trichloride and penta-chloride silicon tetrachloride. Aluminium chloride and titanium(iv) chloride are rather less reactive. 

Aqua-1,2-diaminoethanediperoxochromium(IV), 0961 Aqua-1,2-diaminopropanediperoxochromium(IV) dihydrate, 1332 fraws-Aquadioxo(terpyridine)ruthenium(2+) diperchlorate, 3680 Aquafluorobis(l, lO-phenanthroline)chromium(III) perchlorate, 3840 Aquaglycinatonitratocopper, see Copper(II) glycinate nitrate, 0901 Argon, 0091 Arsenic, 0092 Arsenic pentaazide, 0103b Arsenic pentafluoride, 0095a Arsenic pentaoxide, 0106 Arsenic trichloride, 0094 Arsenic trioxide, 0105 Arsenic trisulfide, 0108 Arsenous triazide, see Triazidoarsine, 0103a Arsine—boron tribromide, 0101 f Arsine, 0100... 

A comparison of catalytic activity of the triphenyl phosphate complexes of boron trifluoride,boron trichloride and boron tribromide showed that comparable rates of polymerization were obtained using the chloride or bromide complexes. The fluoride complex gave about half the rate of the bromide or chloride comparable molecular weights were obtained in all three cases. 

Nonmetal Halides. Vigorous or explosive reactions occur with phosphorus tribromide on addition of drops of water,20 phosphorus trichloride, phosphorus pentachloride,21 diselenium dichloride,22 sulfur dichloride, boron tribromide, sulfur dibromide,17 seleninyl bromide,23 phosphoryl chloride, sulfinyl fluoride, silicon tetrachloride, and silicon tetrafluoride.24... 

The reaction of ( + )-bulbocapnine methyl ether (42) with excess boron trichloride in methylene chloride containing 0.3% ethanol produces the catechol (43) together with the monophenol (44). However, with boron tribromide, it is the diphenol (45) which is produced. Both compounds (44) and (45) can be O-methylated with diazomethane to the dimethyl ether (46), and hydrolysis of (46) with dilute hydrochloric acid leads to (+)-corytuberine (47).43 Alternatively, methylation of (43), using diazomethane, affords (+)-corydine methyl ether (48). 

Boron trichloride, boron tribromide, and boron triiodide, in contrast to the trifluoride, are all rapidly hydrolyzed in water (explosively so in the case of BI3) to generate B(OH)3 and HX as indicated above, all are stronger Lewis acids than BF3. While BC13 and BBr3 are volatile liquids, BI3 is an unstable white solid that polymerizes on standing. The BX anions are all known, but the larger ones —especially BI4—require stabilization by a large cation. 

Boron trichloride and tribromide exchange ligands when used with alkyl halides and acetates initiators. For example, as shown in Eq. (35), 1-phenylethyl bromide and BBr2Cl are formed rapidly and quantitatively when 1-phenylethyl chloride is mixed with an equimolar amount of boron tribromide [59,67]. 

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