Photocatalytic oxidation of bromide to bromine

Kelvin Yun Da Tsai; I. Jy Chang

doi:10.1021/acs.inorgchem.6b01652

Photocatalytic oxidation of bromide to bromine

Kelvin Yun Da Tsai, I. Jy Chang^*

^*Corresponding author for this work

Department of Chemistry

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

17 Citations (Scopus)

Abstract

Three consecutive bimolecular reactions are employed to photocatalyze bromide oxidation to bromine. The system consists of a ruthenium(II) complex, [Ru(deeb)₂(dmbpy)]²⁺ (deeb = 4,4'-diethylester-2,2'-bipyridine; dmbpy = 4,4'-dimethyl-2,2'-bipyridine), 4-bromobenzenediazonium tetrafluoroborate (ArN₂BF₄), and Br-. Varying reagent concentrations allowed us to optimize the sequence of reactions for product formation. The electronically excited ruthenium complex (^∗Ru) reacts first with ArN2BF4 to produce a ruthenium(III) (Ru^III) intermediate, triggering a subsequent reaction with Br-. Transient absorption measured at 486 and 380 nm provides insight into the time-dependent concentrations of ^∗Ru, Ru^III, and Br₂^•- Without interference of backelectron transfer, the rate constant for an equal concentration bimolecular reaction of Br₂^•- was determined to be 5 × 10⁹ M^-1 s^-1. The final products, bromine and tribromide, were spectroscopically characterized, and the turnover number (TON) was 230.

Original language	English
Pages (from-to)	693-696
Number of pages	4
Journal	Inorganic Chemistry
Volume	56
Issue number	2
DOIs	https://doi.org/10.1021/acs.inorgchem.6b01652
Publication status	Published - 2017 Jan 17

ASJC Scopus subject areas

Physical and Theoretical Chemistry
Inorganic Chemistry

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10.1021/acs.inorgchem.6b01652

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title = "Photocatalytic oxidation of bromide to bromine",

abstract = "Three consecutive bimolecular reactions are employed to photocatalyze bromide oxidation to bromine. The system consists of a ruthenium(II) complex, [Ru(deeb)2(dmbpy)]2+ (deeb = 4,4'-diethylester-2,2'-bipyridine; dmbpy = 4,4'-dimethyl-2,2'-bipyridine), 4-bromobenzenediazonium tetrafluoroborate (ArN2BF4), and Br-. Varying reagent concentrations allowed us to optimize the sequence of reactions for product formation. The electronically excited ruthenium complex (∗Ru) reacts first with ArN2BF4 to produce a ruthenium(III) (RuIII) intermediate, triggering a subsequent reaction with Br-. Transient absorption measured at 486 and 380 nm provides insight into the time-dependent concentrations of ∗Ru, RuIII, and Br2•- Without interference of backelectron transfer, the rate constant for an equal concentration bimolecular reaction of Br2•- was determined to be 5 × 109 M-1 s-1. The final products, bromine and tribromide, were spectroscopically characterized, and the turnover number (TON) was 230.",

author = "Tsai, {Kelvin Yun Da} and Chang, {I. Jy}",

note = "Publisher Copyright: {\textcopyright} 2016 American Chemical Society.",

year = "2017",

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day = "17",

doi = "10.1021/acs.inorgchem.6b01652",

language = "English",

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pages = "693--696",

journal = "Inorganic Chemistry",

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T1 - Photocatalytic oxidation of bromide to bromine

AU - Tsai, Kelvin Yun Da

AU - Chang, I. Jy

PY - 2017/1/17

Y1 - 2017/1/17

N2 - Three consecutive bimolecular reactions are employed to photocatalyze bromide oxidation to bromine. The system consists of a ruthenium(II) complex, [Ru(deeb)2(dmbpy)]2+ (deeb = 4,4'-diethylester-2,2'-bipyridine; dmbpy = 4,4'-dimethyl-2,2'-bipyridine), 4-bromobenzenediazonium tetrafluoroborate (ArN2BF4), and Br-. Varying reagent concentrations allowed us to optimize the sequence of reactions for product formation. The electronically excited ruthenium complex (∗Ru) reacts first with ArN2BF4 to produce a ruthenium(III) (RuIII) intermediate, triggering a subsequent reaction with Br-. Transient absorption measured at 486 and 380 nm provides insight into the time-dependent concentrations of ∗Ru, RuIII, and Br2•- Without interference of backelectron transfer, the rate constant for an equal concentration bimolecular reaction of Br2•- was determined to be 5 × 109 M-1 s-1. The final products, bromine and tribromide, were spectroscopically characterized, and the turnover number (TON) was 230.

AB - Three consecutive bimolecular reactions are employed to photocatalyze bromide oxidation to bromine. The system consists of a ruthenium(II) complex, [Ru(deeb)2(dmbpy)]2+ (deeb = 4,4'-diethylester-2,2'-bipyridine; dmbpy = 4,4'-dimethyl-2,2'-bipyridine), 4-bromobenzenediazonium tetrafluoroborate (ArN2BF4), and Br-. Varying reagent concentrations allowed us to optimize the sequence of reactions for product formation. The electronically excited ruthenium complex (∗Ru) reacts first with ArN2BF4 to produce a ruthenium(III) (RuIII) intermediate, triggering a subsequent reaction with Br-. Transient absorption measured at 486 and 380 nm provides insight into the time-dependent concentrations of ∗Ru, RuIII, and Br2•- Without interference of backelectron transfer, the rate constant for an equal concentration bimolecular reaction of Br2•- was determined to be 5 × 109 M-1 s-1. The final products, bromine and tribromide, were spectroscopically characterized, and the turnover number (TON) was 230.

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JO - Inorganic Chemistry

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Photocatalytic oxidation of bromide to bromine

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CCDC 1535733: Experimental Crystal Structure Determination

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Photocatalytic oxidation of bromide to bromine

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CCDC 1535733: Experimental Crystal Structure Determination

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