Borate complexes metaborates

Borate complexes have been utilized by Brigl and Griiner47 to effect partial esterification. Anhydrous D-glucose and metaboric acid dissolved in acetone give a complex which exhibits the analysis of a diborate. Reaction of the latter with an excess of benzoyl chloride gives 2,6-di-O-benzoyl-D-glucose (XL). D-Mannitol likewise forms a diborate, which produces the 1,6-di-O-benzoyl derivative (XLI) upon benzoylation. In the presence of boric acid, D-glucose diethyl thioacetal yields the 6-benzoate (XLII). In the non-aqueous medium the formation of complexes... 

Some authors assume that the metal metaborate may combine with sodium metaborate to give complex borates of the type Na2[Cu(B02)4], Na2[Ni(B02)4] and Na2[Co(B02)4] ... 

Ebelman and Bouquet prepared the first examples of boric acid esters in 1846 from boron trichloride and alcohols. Literature reviews of this subject are available. B The general class of boric acid esters includes the more common orthoboric acid based trialkoxy- and triaryloxyboranes, B(0R)3 (1), and also the cyclic boroxins, (ROBO)3, which are based on metaboric acid (2). The boranes can be simple trialkoxyboranes, cyclic diol derivatives, or more complex trigonal and tetrahedral derivatives of polyhydric alcohols. Nomenclature is confusing in boric acid ester chemistry. Many trialkoxy- and triaryloxyboranes such as methyl, ethyl, and phenyl are commonly referred to simply as methyl, ethyl, and phenyl borates. The lUPAC boron nomenclature committee has recommended the use of trialkoxy- and triaryloxyboranes for these compounds, but they are referred to in the literature as boric acid esters, trialkoxy and triaryloxy borates, trialkyl and triaryl borates or orthoborates, and boron alkoxides and aryloxides. The lUPAC nomenclature will be used in this review except for relatively common compounds such as methyl borate. Boroxins are also referred to as metaborates and more commonly as boroxines. Boroxin is preferred by the lUPAC nomenclature committee and will be used in this review. 

A recent publication by Flaaten et al. has claimed that borates, notably sodium metaborate, unlike conventional alkalis, exhibit a remarkable tolerance toward hardness ions, in this application [19], This discovery will allow (notably carbonate) reservoirs with hard saline brines to benefit from the use of ASP flooding technology, where previously this was not possible. The metaborate ion is known to form ion-pair complexes with hardness ions, for example, the reaction with calcium ion is as follows ... 

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