Photochemistry of the μ-hydroxo-μ-peroxo- bis[triethylenetetraamine)cobalt(III)] complex in basic aqueous solutions

Shinohara, Naohide; Matsufuji, Shigeo; Okubo, Wataru

doi:10.1016/s0277-5387(00)83556-1

Cited by 7 publications

(3 citation statements)

References 30 publications

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“…Although the initial reaction rate was always observed to be the highest one for all the reaction conditions (this contrasts with the increase of the 337 nm peak in the 0–20 min range), one can suppose that this absorption corresponds to an intermediate compound, a component of the reaction solution. Unfortunately, it is not possible to assign this peak to some definite compound because of the great complexity of the catalytic systemthe absorbance at about 330 nm could be due to organic species or charge transfer in cobalt or iron coordination compounds, including peroxo- and hydroxyperoxo species of these metals …”

Section: Resultsmentioning

confidence: 99%

Heterometallic Co^III₄Fe^III₂Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

et al. 2012

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The heterometallic complex [Co(4)Fe(2)OSae(8)]·4DMF·H(2)O (1) was synthesized by one-pot reaction of cobalt powder with iron chloride in a dimethylformamide solution of salicylidene-2-ethanolamine (H(2)Sae) and characterized by single crystal X-ray diffraction analysis, magnetic measurements, high frequency electron paramagnetic resonance (HF-EPR), and Mössbauer spectroscopies. The exchange coupling in the Fe(III)-Fe(III) pair is of antiferromagnetic behavior with J/hc = -190 cm(-1). The HF-EPR spectra reveal an unusual pattern with a hardly detectable triplet signal of the Fe(III) dimer. The magnitude of D (ca. 13.9 cm(-1)) was found to be much larger than in related dimers. The catalytic investigations disclosed an outstanding activity of 1 toward oxidation of cycloalkanes with hydrogen peroxide, under mild conditions. The most efficient system showed a turnover number (TON) of 3.57 × 10(3) with the concomitant overall yield of 26% for cyclohexane, and 2.28 × 10(3)/46%, respectively, for cyclooctane. A remarkable turnover frequency (TOF) of 1.12 × 10(4) h(-1) (the highest initial rate W(0) = 3.5 × 10(-4) M s(-1)) was achieved in oxidation of cyclohexane. Kinetic experiments and selectivity parameters led to the conclusion that hydroxyl radicals are active (attacking C-H bonds) species. Kinetic and electrospray ionization mass spectrometry (ESI-MS) data allowed us to assume that the trinuclear heterometallic particle [Co(2)Fe(Sae)(4)](+), originated from 1 in solution, could be responsible for efficient generation of hydroxyl radicals from hydrogen peroxide.

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Section: Resultsmentioning

confidence: 99%

Heterometallic Co^III₄Fe^III₂Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

et al. 2012

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“…The photochemistry of η 1 metal hydroperoxides is largely unexplored, but the peroxo complexes have received some attention, mostly in the context of photochemically induced oxidation of organic materials. Evolution of oxygen is often observed, − but the detailed mechanism(s) of such reactions have been investigated in only a few cases. The photolysis of an oxoperoxovanadium(V) complex, VO(O 2 ) + , yields the hydroperoxyl radical, HO 2 • , which reacts with more VO(O 2 ) + and produces O 2 and H 2 O 2 via an observable intermediate believed to be VO(O 2 )(HO 2 ) + .…”

Section: Introductionmentioning

confidence: 99%

Macrocyclic Hydroperoxocobalt(III) Complex: Photochemistry, Spectroscopy, and Crystal Structure

Guzei

Bakač

2001

Inorg. Chem.

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The hydroperoxocobalt complex [L(2)(CH(3)CN)CoOOH](ClO(4))(2).CH(3)CN (L(2) = meso-5,7,7,12,14,14-Me(6)-[14]aneN(4)) crystallizes with discrete anions, cations, and solvate acetonitrile molecules in the lattice. The complex crystallizes in the monoclinic space group P2(1)/n, a = 10.4230(5) A, b = 16.1561(8) A, c = 17.4676(9) A, beta = 92.267(1) degrees, V = 2939.2(3) A(3), Z = 4. The O-O bond length is 1.397(4) A, and the O(2)-O(1)-Co angle spans 117.7 degrees. The O-O stretch in the infrared spectrum appears at 815 cm(-1). The 355- and 266-nm photolysis of acidic aqueous solutions of L(2)(H(2)O)CoOOH(2+) results in homolytic splitting of the Co-O bond and yields L(2)Co(H(2)O)(2)(2+) and HO(2)(*)/O(2)(*-) as the only products. The two fragments were scavenged selectively in separate experiments with O(2) and C(NO(2))(4). There is no evidence for photochemical O-O bond homolysis, presumably because the appropriate optical transition is masked by the HO(2)-to-Co LMCT transition.

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“…For polynuclear complexes of cadmium, see: Evans & Lin (2002); For background to the use of the trien ligand in complexation, see: Cai et al (2001a,b); Buckingham et al (1974Buckingham et al ( , 1975; Chowdhury et al (2007). Buckingham & Jones (1965); Shinohara et al (1991); He (2009) ;Patel et al (2008); Anderson et al (1977); Shoukry et al (1998);Hu et al (2000). For dinuclear Cd complexes, see: Das et al (2010); Nie et al (2010); Wang et al (2011);Sun et al (2010).…”

Section: Related Literaturementioning

confidence: 99%

[μ-N,N′-Bis(2-aminoethyl)ethane-1,2-diamine-κ⁴N¹,N^1′:N²,N^2′]bis{[N,N′-bis(2-aminoethyl)ethane-1,2-diamine-κ⁴N,N′,N′′,N′′′]cadmium} tetrakis(perchlorate)

Goudarziafshar¹,

Abbasityula²,

Eigner³

et al. 2012

Acta Cryst E

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The centrosymmetric dinuclear cadmium title complex, [Cd2(C6H18N4)3](ClO4)4, was obtained by the reaction of N,N′-bis(2-aminoethyl)ethane-1,2-diamine (trien) with Cd(NO3)2·4H2O and sodium perchlorate in methanol. The CdII cation is coordinated by four N atoms of a non-bridging trien ligand and by two N atoms of a bridging trien ligand in a slightly distorted octahedral coordination geometry. The bridging ligand shares another two N atoms with a neighboring symmetry-equivalent CdII cation. The structure displays C—H⋯O and N—H⋯O hydrogen bonding. The perchlorate anion is disordered over two sets of sites in a 0.854 (7): 0.146 (7) ratio.

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Photochemistry of the μ-hydroxo-μ-peroxo- bis[triethylenetetraamine)cobalt(III)] complex in basic aqueous solutions

Cited by 7 publications

References 30 publications

Heterometallic Co^III₄Fe^III₂Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

Heterometallic Co^III₄Fe^III₂Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

Macrocyclic Hydroperoxocobalt(III) Complex: Photochemistry, Spectroscopy, and Crystal Structure

[μ-N,N′-Bis(2-aminoethyl)ethane-1,2-diamine-κ⁴N¹,N^1′:N²,N^2′]bis{[N,N′-bis(2-aminoethyl)ethane-1,2-diamine-κ⁴N,N′,N′′,N′′′]cadmium} tetrakis(perchlorate)

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Photochemistry of the μ-hydroxo-μ-peroxo- bis[triethylenetetraamine)cobalt(III)] complex in basic aqueous solutions

Cited by 7 publications

References 30 publications

Heterometallic CoIII4FeIII2Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

Heterometallic CoIII4FeIII2Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

Macrocyclic Hydroperoxocobalt(III) Complex: Photochemistry, Spectroscopy, and Crystal Structure

[μ-N,N′-Bis(2-aminoethyl)ethane-1,2-diamine-κ4N1,N1′:N2,N2′]bis{[N,N′-bis(2-aminoethyl)ethane-1,2-diamine-κ4N,N′,N′′,N′′′]cadmium} tetrakis(perchlorate)

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Heterometallic Co^III₄Fe^III₂Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

Heterometallic Co^III₄Fe^III₂Schiff Base Complex: Structure, Electron Paramagnetic Resonance, and Alkane Oxidation Catalytic Activity

[μ-N,N′-Bis(2-aminoethyl)ethane-1,2-diamine-κ⁴N¹,N^1′:N²,N^2′]bis{[N,N′-bis(2-aminoethyl)ethane-1,2-diamine-κ⁴N,N′,N′′,N′′′]cadmium} tetrakis(perchlorate)