On the nature of the peroxoborate ion in solution

Adams, Christopher J.; Clark, I. E.

doi:10.1016/s0277-5387(00)81533-8

Cited by 26 publications

(4 citation statements)

References 7 publications

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“…Ϫ , polyborates, or other boron species in the treated wood blocks is much less than that of B(OH) 3 . This is supported by previous Raman studies for borates in aqueous solution [21][22][23][24] and pH measurements for Japanese cedar. 25…”

Section: Resultssupporting

confidence: 86%

Raman spectroscopic study on the behavior of boric acid in wood

Yamauchi

2003

J Wood Sci

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Raman spectra of Japanese cedar (Cryptomeria japonica D. Don) treated by vacuum impregnation with aqueous boric acid solutions (8.1 ϫ 10 Ϫ2 to 7.29 ϫ 10 Ϫ1 mol dm Ϫ3 ) were recorded using a near-infrared laser as an excitation source. Raman spectroscopic measurements were carried out on treated wood blocks of two sizes: 20(T) ϫ 20(R) ϫ 5(L) mm (A-type) and 15(T) ϫ 15(R) ϫ 50(L) mm (B-type). Our attention was focused on a prominent band (ν 1 ) assigned to a symmetrical stretching vibration of the BO 3 group because no Raman band due to boron species was observed except bands of B(OH) 3 . We observed a change in ν 1 band intensity with increasing boric acid concentration in the aqueous solution used to treat the A-type wood blocks and investigated the correlation between the intensity and the peak-top wavenumber. Raman line maps in the longitudinal direction of the treated B-type wood blocks revealed that B(OH) 3 is concentrated near the cut ends. These results suggested that two groups of B(OH) 3 exist in wood in terms of the chemical species in the nearest neighbor sphere.

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Section: Resultssupporting

confidence: 86%

Raman spectroscopic study on the behavior of boric acid in wood

Yamauchi

2003

J Wood Sci

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“…Taking account of the work of various authors [8][9][10], we may assume that the catalytic effect of boric acid is related to the formation of MPB and DPB anions according to the following equations: 11.9 ± 0.1, k 3 = (2.2 ± 0.1)·10 -2 mol/L·s, and k 4 = -(3 ± 10)·10 -5 mol/L·s. The conditions are given in Table 1.…”

Section: Effect Of Boric Acid On the Rate Of Oxidation Of Et 2 S By Hmentioning

confidence: 99%

“…K 7 and K 8 are equal to 20[8,9] and 2.0 L/mol, respectively. The plots for the dependence of the concentrations of MBP and DBP on the medium acidity is complicated and is a function of the ratio of the starting concentrations of H 2 O 2 and B(OH) 3[8].When[B(OH) 3 ] >> [H 2 O 2 ] >> [Et 2 S], the oxidation of diethyl sulfide may proceed through three parallel pathways: involving H 2 O 2 (reaction (2)), B(OH) 3 (OOH) -, and B(OH) Et 2 S=O + B(OH) 3 (OOH) -.…”

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confidence: 99%

Kinetics of the oxidation of diethyl sulfide in the B(OH)3-H2O2/H2O system

et al. 2007

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Data obtained for the kinetics of oxidation of diethyl sulfide (Et 2 S) by hydrogen peroxide in aqueous solution catalyzed by boric acid indicate that monoperoxoborates B(O 2 H)( ) OH 3 − and diperoxoborates B O H OH ( ) ( ) 2 2 2 − are the active species. The rates of the reactions of Et 2 S with B(O 2 H)( ) OH 3 − and B O H OH ( ) ( ) 2 2 2 − are 2.5 and 100 times greater than with H 2 O 2 .The search for new systems to effect rapid selective oxidation of sulfides and sulfoxides is important for solving the problem of the decomposition of pesticides and poisonous substances, whose active components are organic sulfides. Chloramines, commonly used for this purpose, are highly toxic and corrosive [1]. The most ecologically favorable oxidizing agent is hydrogen peroxide, which, however, has only low reactivity by itself. Bicarbonates [2, 3], molybdates [4,5], phthalates [6], and nitrites [7], which form highly reactive peroxo acids upon reaction with H 2 O 2 , are used to activate hydrogen peroxide. Boric acid, B(OH) 3 , which forms peroxoborates upon reaction with hydrogen peroxide under mild conditions, is a promising activator [8-10]. These compounds, in particular Na 2 [B 2 (O 2 ) 2 (OH) 4 ]·6H 2 O [11], are strong oxidizing agents and are used as industrial bleaches. No information is available on the kinetics and mechanisms of oxidation of thioethers by peroxyborates. The chemistry of peroxyborates is complicated. Depending on the ratio of the starting concentrations of B(OH) 3 and H 2 O 2 and the pH of the medium, either peroxoborates [B(O 2 H) n (OH) 4-n ] -(n = 1-4) or polyperoxoborates [B 2 (O 2 ) 2 (O 2 H) n (OH) 4-n ] 2-(n = 0, 2, or 4) are formed [10]. At relatively low concentrations of B(OH) 3 and H 2 O 2 (£1 mol/L) at pH 6-14, the major products are monoperoxoborate B(O H)(OH) 2 3 − (MPB) anions and diperoxoborate B(O H) (OH) 2 2 2 − (DPB)anions. Polyperoxoborates are the major products at higher reagent concentrations.In the present work, we studied the effect of boric acid on the rate of oxidation of diethyl sulfide (Et 2 S), which serves as a model for yprite, by hydrogen peroxide in aqueous solution in a broad pH range to establish the nature of the active species and find optimal reaction conditions. EXPERIMENTALDiethyl sulfide was prepared according to a standard procedure [12]. The working solutions were prepared using doubly distilled water, 35% hydrogen peroxide, and chemically-pure grade samples of boric acid, sodium perchlorate, H 3 PO 4 , and NaOH. 440040-5760/07/4301-0044

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“…The 11 BNMR spectrum of B-rCPOa th igh concentration (1.5 mm)p repared in acetate buffer (100 mm,p H5.0) shows one single peak at 21.80 ppm (see Supporting Information Figure S5 blue line) that is attributedt oB (OH) 3 in ad ifferent environment. [40][41][42] The 11 BNMR spectrum of free B(OH) 3 prepared in acetate buffer (100 mm,p H5.0) shows also one singlep eak at 19.38 ppm (see Supporting Information Figure S5 green line). This spectral shift (19.38!21.80 ppm) is attributed to B(OH) 3 -enzyme interactions in agreement with molecular simulations ( Figure 3b).…”

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confidence: 99%

Reconstitution of Vanadium Haloperoxidase's Catalytic Activity by Boric Acid—Towards a Potential Biocatalytic Role of Boron

Natálio

Wiese

Brandt

et al. 2017

Chemistry A European J

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Boron's unusual properties inspired major advances in chemistry. In nature, the existence and importance of boron has been fairly explored (e.g. bacterial signaling, plant development) but its role as biological catalyst was never reported. Here, we show that boric acid [B(OH) ] can restore chloroperoxidase activity of Curvularia inaequalis recombinant apo-haloperoxidase's (HPO) in the presence of hydrogen peroxide and chloride ions. Molecular modeling and semi-empirical PM7 calculations support a thermodynamically highly favored (bio)catalytic mechanism similarly to vanadium haloperoxidases (V-HPO) in which [B(OH) ] is assumedly located in apo-HPO's active site and a monoperoxyborate [B(OH) (OOH) ] intermediate is formed and stabilized by interaction with specific active site amino acids leading ultimately to the formation of HOCl. Thus, B(OH) -HPO provides the first evidence towards the future exploitation of boron's role in biological systems.

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On the nature of the peroxoborate ion in solution

Cited by 26 publications

References 7 publications

Raman spectroscopic study on the behavior of boric acid in wood

Raman spectroscopic study on the behavior of boric acid in wood

Kinetics of the oxidation of diethyl sulfide in the B(OH)3-H2O2/H2O system

Reconstitution of Vanadium Haloperoxidase's Catalytic Activity by Boric Acid—Towards a Potential Biocatalytic Role of Boron

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