Photoinduced radical chain reactions between alkylcobalt(III) complexes and iodine

Kunio Ishikawa; Shunichi Fukuzumi; Tatsushi Goto; Toshio Tanaka

doi:10.1039/DT9900000085

Photoinduced radical chain reactions between alkylcobalt(III) complexes and iodine

Kunio Ishikawa
, Shunichi Fukuzumi
, Tatsushi Goto
, Toshio Tanaka

Department of Chemistry & Nanoscience

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

3 Scopus citations

Abstract

Cobalt-carbon bonds of various alkylcobalt(III) complexes, cis-[CoR₂(bipy)₂]ClO₄ (R = Me, Et, or PhCH₂; bipy = 2,2′-bipyridine), trans-[CoMe₂(L)] (L = 3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioximate), and [CoR(Hdmg)₂(py)] (R = Me or Et; Hdmg = dimethylglyoximate; py = pyridine), are readily cleaved by iodine in carbon tetrachloride to yield alkyl iodides via photoinduced radical chain reactions with large quantum yields (e.g. Φ = 7.0 × 10³) under low-energy irradiation (λ 517 nm). The rate-determining step in the radical chain reactions is suggested to be electron transfer from alkylcobalt(III) complexes to iodine atoms (I^.) which are produced by the photodissociation of I₂, based on the formation of by-products that could arise only via electron-transfer processes as well as the kinetic comparison between alkylcobalt(III) complexes and tetra-alkyltin compounds.

Original language	English
Pages (from-to)	85-90
Number of pages	6
Journal	Journal of the Chemical Society. Dalton Transactions
Issue number	1
DOIs	https://doi.org/10.1039/DT9900000085
State	Published - 1990

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@article{87a23ecfcb3541f78e066b481d1ed910,

title = "Photoinduced radical chain reactions between alkylcobalt(III) complexes and iodine",

abstract = "Cobalt-carbon bonds of various alkylcobalt(III) complexes, cis-[CoR2(bipy)2]ClO4 (R = Me, Et, or PhCH2; bipy = 2,2′-bipyridine), trans-[CoMe2(L)] (L = 3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioximate), and [CoR(Hdmg)2(py)] (R = Me or Et; Hdmg = dimethylglyoximate; py = pyridine), are readily cleaved by iodine in carbon tetrachloride to yield alkyl iodides via photoinduced radical chain reactions with large quantum yields (e.g. Φ = 7.0 × 103) under low-energy irradiation (λ 517 nm). The rate-determining step in the radical chain reactions is suggested to be electron transfer from alkylcobalt(III) complexes to iodine atoms (I.) which are produced by the photodissociation of I2, based on the formation of by-products that could arise only via electron-transfer processes as well as the kinetic comparison between alkylcobalt(III) complexes and tetra-alkyltin compounds.",

author = "Kunio Ishikawa and Shunichi Fukuzumi and Tatsushi Goto and Toshio Tanaka",

year = "1990",

doi = "10.1039/DT9900000085",

language = "English",

pages = "85--90",

journal = "Journal of the Chemical Society. Dalton Transactions",

issn = "1472-7773",

publisher = "Royal Society of Chemistry",

number = "1",

}

TY - JOUR

T1 - Photoinduced radical chain reactions between alkylcobalt(III) complexes and iodine

AU - Ishikawa, Kunio

AU - Fukuzumi, Shunichi

AU - Goto, Tatsushi

AU - Tanaka, Toshio

PY - 1990

Y1 - 1990

N2 - Cobalt-carbon bonds of various alkylcobalt(III) complexes, cis-[CoR2(bipy)2]ClO4 (R = Me, Et, or PhCH2; bipy = 2,2′-bipyridine), trans-[CoMe2(L)] (L = 3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioximate), and [CoR(Hdmg)2(py)] (R = Me or Et; Hdmg = dimethylglyoximate; py = pyridine), are readily cleaved by iodine in carbon tetrachloride to yield alkyl iodides via photoinduced radical chain reactions with large quantum yields (e.g. Φ = 7.0 × 103) under low-energy irradiation (λ 517 nm). The rate-determining step in the radical chain reactions is suggested to be electron transfer from alkylcobalt(III) complexes to iodine atoms (I.) which are produced by the photodissociation of I2, based on the formation of by-products that could arise only via electron-transfer processes as well as the kinetic comparison between alkylcobalt(III) complexes and tetra-alkyltin compounds.

AB - Cobalt-carbon bonds of various alkylcobalt(III) complexes, cis-[CoR2(bipy)2]ClO4 (R = Me, Et, or PhCH2; bipy = 2,2′-bipyridine), trans-[CoMe2(L)] (L = 3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioximate), and [CoR(Hdmg)2(py)] (R = Me or Et; Hdmg = dimethylglyoximate; py = pyridine), are readily cleaved by iodine in carbon tetrachloride to yield alkyl iodides via photoinduced radical chain reactions with large quantum yields (e.g. Φ = 7.0 × 103) under low-energy irradiation (λ 517 nm). The rate-determining step in the radical chain reactions is suggested to be electron transfer from alkylcobalt(III) complexes to iodine atoms (I.) which are produced by the photodissociation of I2, based on the formation of by-products that could arise only via electron-transfer processes as well as the kinetic comparison between alkylcobalt(III) complexes and tetra-alkyltin compounds.

UR - https://www.scopus.com/pages/publications/37049088744

U2 - 10.1039/DT9900000085

DO - 10.1039/DT9900000085

M3 - Article

AN - SCOPUS:37049088744

SN - 1472-7773

SP - 85

EP - 90

JO - Journal of the Chemical Society. Dalton Transactions

JF - Journal of the Chemical Society. Dalton Transactions

IS - 1

ER -

Photoinduced radical chain reactions between alkylcobalt(III) complexes and iodine

Abstract

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