Ammonium tetraborate

Ammonium tetraborate tetrahydrate is prepared by crystallization from an aqueous solution of boric acid and ammonia having a B202 (NH4)20 ratio of 1.8 2.1. Ammonium pentaborate is similarly produced from an aqueous solution of boric acid and ammonia having a B202 (NH4)20 ratio of 5. Supersaturated solutions are easily formed and the rate of crystallization is proportional to the extent of supersaturation (130). A process for the production... 

Ammonium acetate Ammonium adipate Ammonium benzoate Ammonium bicarbonate Ammonium biflluoride Ammonium binoxalate Ammonium bisulfate Ammonium bitartrate Ammonium tetraborate Ammonium bromide Ammonium carbonate Ammonium chloride Ammonium citrate Ammonium diclnomate Ammonium fluoride Ammonium fluorosilicate Ammonium gluconate Ammonium iodide Ammonium molybdate Ammonium nitrate Ammonium oxalate Ammonium perchlorate Ammonium picrate Ammonium polysulfide Ammonium salicylate Ammonium stearate Ammonium sulfate Ammonium sulfide (hydrosulfide) Ammonium tartrate Ammonium tliiocyanate Ammonium thiosulfate... 

Many borates are known that contain non-metal cations. Examples include the ammonium borates [39], such as the commercial products ammonium pentaborate, NH4[B506(0H)4] 2 H2O, and ammonium tetraborate, (NH4)2 [6405(011)4] 2 H2O, both of which contain isolated borate anions shown above (Figs. 5a and 6a, respectively) [40]. Isolated borate anions containing more than six boron atoms are rare. However, the mineral ammonioborite [(NH4)3[Bi502o(OH)g] 4 H20 = (NH4)20 5 B2O3 2 2/3 H2O), which may be prepared synthetically by prolonged reflux of a saturated solution of ammonium pentaborate, contains the unusual isolated anion [Bi502o(OH)g] , shown in Fig. 10 [41]. This anion is not known to occur in any metal borate, its formation is apparently directed exclusively by the ammonium cations which can donate H-bonds to interstitial water and the borate structural unit. 

Bowden GH (1980) Boron Oxygen Compounds. Mellor s Comprehensive Treatise on Inorganic and Theoretical Chemistry, Vol V. Longman Group, London Ammonium tetraborate is known as an article of commerce by the name ammonium biborate ... 

BN fibers can be made by decomposition of hydrated cellulose impregnated with boric acid or ammonium tetraborate (NH4B407) in ammonia and nitrogen atmosphere at elevated temperatures (>1000 °C) [148, 149]. 

Ammonium borates.—Many borates of ammonium have been described, hut their existence as definite chemical individuals is in most instances doubtful.18 Ammonium tetraborate, (NH4)2B407,4H20, is prepared by cooling a warm solution of boric acid in excess of ammonium hydroxide. It forms tetragonal crystals,19 soluble in 12 times their weight of water at the ordinary temperature. 

Another experiment consisted in impregnating alumina with ammonium tetraborate (NH4)2B204 (Aldrich, 99%). The product was calcined at 1000°C for 24h and 1100°C for 4h. The sample was named 9A2B2. 

Figure 4. Dowex-l-X8 borate anion-exchange column chromatographic analysis of supernatants from 24 hour incubations of P. putida with 4-deoxy-4-fluoro-D-(U- C)glucose. 0 Radiolabeled metabolites internal non-radiolabeled carbohydrate standards. All compounds were eluted with a linear gradient of ammonium tetraborate.

Synonyms Ammonium borate Ammonium metaborate Ammonium tetraborate Diammonium tetraborate Diammonium tetraborate tetrahydrate... 

The reagents NaOH, Mg(N03)2.6H20 (Janssen), A1(N03)3.9H20 (Katayama), adipic acid (Hanawa), and ammonium tetraborate tetrahydrate (Aldrich) were used as received. Three different methods for preparation of borate-hydrotalcite-like LDHs were compared. The procedures are described in scheme 1. 

To a 16.6 g portion of preceding adipate-hydrotalcite-clay slurry, a solution consisting of 10.72 g of ammonium tetraborate tetrahydiate in lOOmL of deionized water was added. The suspensioi (pH=9.5) was stined and heated at 363 K (or given temperature) for 6 h, followed by filtering, washing with deionized wat , and drying at 323 K. 

The IR spectra of the pillared derivatives were compared with that of nitrate-hydrotalcite and ammonium tetraborate (Fig. 8.5). The absorption peak at 1384 cm in Fig. 8.5(a) is attributed to the nitrate ions in nitrate-hydrotalcite. Fig. 8.5(b) shows the IR spectrum of adipate-hydrotalcite prepared by the coprecipitation method. The bands at 2921, 2934, and 2951 cm correspond to the me ylene groups of adipate ions. The presence of an absorption peak at... 

Fig. 8.5. IR spectra of (a) nitrate-hydrotaldte (b) adipate-hydrotaldte (c) borate-hydrotaldte-like LDHs (d) ammonium tetraborate.

A suspension of sieved ECTEOLA-cellulose powder (Firm 127) (2 g) in 0.004 M ethylenediaminetetraacetic acid, pH 7.0 (18 ml) is shaken vigorously for 5 min. The slurry is spread uniformly on a glass plate (20 X 20 cm) and dried overnight at room temperature giving a layer about 200 [X thick. The dried layer is then sprayed with 0.1 M ammonium tetraborate, pH 9.0, hnd dried at 50° for 30 min. No changes are found on storing the plates for 3 days. 

The sugar phosphates are separated on ECTEOLA-cellulose thin-layers impregnated with ammonium tetraborate (see section II, 6) with solvent XXV [11]. The mobility of the sugars is altered by preparing the solvent and plates with pH 10 ammonium tetraborate buffer. Table 207 gives the mobilities of some common sugar phosphates. 

T8 = ECTEOLA-ccllulose sprayed with 0.01 ammonium tetraborate (pH 9.0) and dried with 17 cm run. 2 hours/closed tank. = R, rel to inorg. Phosphate... 

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