Boron complexes salicylic acid

In addition to BF4 , other anionic boron complexes, also forming ion-associates with basic dyes, have been applied to determine boron, namely 2,4-dinitro-1,8-naphthalenediol and Brilliant Green (formula 4.26) (toluene, e = 1.0-10 at 637 nm [41 3], 2,6-dihydroxy-benzoic acid, and Malachite Green (chlorobenzene, e = 9.5-10 [5], 2,3-dihydroxy-naphthalene and Crystal Violet (benzene, e = 8.8-10 [44]), mandelic acid, and Malachite Green (benzene, e = 6.5-10 ) [45,46], pyrocatechol derivatives, and Ethyl Violet (toluene, e = 1.05-10 [47,48]. The ion-pair of the salicylate complex of boron with ferroin has also been proposed (CHCI3) [49]. 

Boron-Oxygen Compounds. Studies of the formation of chelate complexes of boric acid and of boronic acids continue to appear. A two-stage process for the reaction between boric acid and salicylic acid is observed. Studies on a range of substituted catechols are interpreted as indicating a transition state in which proton transfer is important. 

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