Kinetic Study of Boric Acid-Borate Interchange in Aqueous Solution by 11B NMR Spectroscopy

Koji Ishihara; Akira Nagasawa; Kimiko Umemoto; Hideaki Ito; Kazuo Saito

doi:10.1021/ic00095a026

Kinetic Study of Boric Acid-Borate Interchange in Aqueous Solution by ¹¹B NMR Spectroscopy

Koji Ishihara^*, Akira Nagasawa, Kimiko Umemoto, Hideaki Ito, Kazuo Saito

^*Corresponding author for this work

School of Advanced Science and Engineering

Research output: Contribution to journal › Article › peer-review

55 Citations (Scopus)

Abstract

Kinetics of interchange between boric acid and tetrahydroxyborate has been studied by the band shape analysis of ¹¹B NMR signals in aqueous solution of pH 8–10 at 20–52 °C and 0.1–250 MPa. The system was analyzed as two-site exchange B(OH)₃ ⇌ B(OH)₄-. The observed first-order rate constant toward the right (k_X) is related to the second-order exchange rate constant (k_ex) by the equation k_X = k_exC_T[OH^-]/(k_b + [OH^-]), where k_b = [B(OH)₃][OH^-]/[B(OH)₄^-], and C_T is the total concentration of boron. Under the given conditions k_ex is (2–7) × 10⁶ dm³ mol^-1 s^-1 and ΔH‡, ΔS‡, and ΔV‡ are 20.1 ± 1.0 kJ mol^-1, -55.0 ± 3.1 J mol^-1 K^-1, and -9.9 ± 0.5 cm³ mol^-1, respectively. The activation parameters reflect the transition state forming dimeric [(OH)₃B(μ-OH)B(OH)₃]^-. The results are compared with those of related reactions.

Original language	English
Pages (from-to)	3811-3816
Number of pages	6
Journal	Inorganic Chemistry
Volume	33
Issue number	17
DOIs	https://doi.org/10.1021/ic00095a026
Publication status	Published - 1994 Aug 1

ASJC Scopus subject areas

Physical and Theoretical Chemistry
Inorganic Chemistry

Access to Document

10.1021/ic00095a026

Cite this

@article{1ef5428a1173440f95a4863475113438,

title = "Kinetic Study of Boric Acid-Borate Interchange in Aqueous Solution by 11B NMR Spectroscopy",

abstract = "Kinetics of interchange between boric acid and tetrahydroxyborate has been studied by the band shape analysis of 11B NMR signals in aqueous solution of pH 8–10 at 20–52 °C and 0.1–250 MPa. The system was analyzed as two-site exchange B(OH)3 ⇌ B(OH)4-. The observed first-order rate constant toward the right (kX) is related to the second-order exchange rate constant (kex) by the equation kX = kexCT[OH-]/(kb + [OH-]), where kb = [B(OH)3][OH-]/[B(OH)4-], and CT is the total concentration of boron. Under the given conditions kex is (2–7) × 106 dm3 mol-1 s-1 and ΔH‡, ΔS‡, and ΔV‡ are 20.1 ± 1.0 kJ mol-1, -55.0 ± 3.1 J mol-1 K-1, and -9.9 ± 0.5 cm3 mol-1, respectively. The activation parameters reflect the transition state forming dimeric [(OH)3B(μ-OH)B(OH)3]-. The results are compared with those of related reactions.",

author = "Koji Ishihara and Akira Nagasawa and Kimiko Umemoto and Hideaki Ito and Kazuo Saito",

year = "1994",

month = aug,

day = "1",

doi = "10.1021/ic00095a026",

language = "English",

volume = "33",

pages = "3811--3816",

journal = "Inorganic Chemistry",

issn = "0020-1669",

publisher = "American Chemical Society",

number = "17",

}

TY - JOUR

T1 - Kinetic Study of Boric Acid-Borate Interchange in Aqueous Solution by 11B NMR Spectroscopy

AU - Ishihara, Koji

AU - Nagasawa, Akira

AU - Umemoto, Kimiko

AU - Ito, Hideaki

AU - Saito, Kazuo

PY - 1994/8/1

Y1 - 1994/8/1

N2 - Kinetics of interchange between boric acid and tetrahydroxyborate has been studied by the band shape analysis of 11B NMR signals in aqueous solution of pH 8–10 at 20–52 °C and 0.1–250 MPa. The system was analyzed as two-site exchange B(OH)3 ⇌ B(OH)4-. The observed first-order rate constant toward the right (kX) is related to the second-order exchange rate constant (kex) by the equation kX = kexCT[OH-]/(kb + [OH-]), where kb = [B(OH)3][OH-]/[B(OH)4-], and CT is the total concentration of boron. Under the given conditions kex is (2–7) × 106 dm3 mol-1 s-1 and ΔH‡, ΔS‡, and ΔV‡ are 20.1 ± 1.0 kJ mol-1, -55.0 ± 3.1 J mol-1 K-1, and -9.9 ± 0.5 cm3 mol-1, respectively. The activation parameters reflect the transition state forming dimeric [(OH)3B(μ-OH)B(OH)3]-. The results are compared with those of related reactions.

AB - Kinetics of interchange between boric acid and tetrahydroxyborate has been studied by the band shape analysis of 11B NMR signals in aqueous solution of pH 8–10 at 20–52 °C and 0.1–250 MPa. The system was analyzed as two-site exchange B(OH)3 ⇌ B(OH)4-. The observed first-order rate constant toward the right (kX) is related to the second-order exchange rate constant (kex) by the equation kX = kexCT[OH-]/(kb + [OH-]), where kb = [B(OH)3][OH-]/[B(OH)4-], and CT is the total concentration of boron. Under the given conditions kex is (2–7) × 106 dm3 mol-1 s-1 and ΔH‡, ΔS‡, and ΔV‡ are 20.1 ± 1.0 kJ mol-1, -55.0 ± 3.1 J mol-1 K-1, and -9.9 ± 0.5 cm3 mol-1, respectively. The activation parameters reflect the transition state forming dimeric [(OH)3B(μ-OH)B(OH)3]-. The results are compared with those of related reactions.

UR - http://www.scopus.com/inward/record.url?scp=0012868995&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0012868995&partnerID=8YFLogxK

U2 - 10.1021/ic00095a026

DO - 10.1021/ic00095a026

M3 - Article

AN - SCOPUS:0012868995

SN - 0020-1669

VL - 33

SP - 3811

EP - 3816

JO - Inorganic Chemistry

JF - Inorganic Chemistry

IS - 17

ER -

Kinetic Study of Boric Acid-Borate Interchange in Aqueous Solution by ¹¹B NMR Spectroscopy

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this