Re-examination of the photochemical reaction of octaisopropylcyclotetragermane

Wakasa, Masanobu; Takamori, Yuya; Takayanagi, Toshiyuki; Orihara, Masayuki; Kugita, Tsuyoshi

doi:10.1016/j.jorganchem.2007.03.017

Cited by 4 publications

(3 citation statements)

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“…Better time resolution will be required for even a tentative identification to be made of the short-lived transient species detected in these experiments. It is worth noting that Wakasa and co-workers recently reported evidence from laser photolysis and product studies for the formation of a related (1,4-) biradical from the photolysis of octa(isopropyl)cyclotetragermane; the species exhibits a long-wavelength absorption band centered at λ max = 550 nm and lifetime τ = 50 ± 5 ns in cyclohexane at 25 °C …”

Section: Resultsmentioning

confidence: 99%

Laser Flash Photolysis Studies of Some Dimethylgermylene Precursors

Lollmahomed

Leigh

2009

Organometallics

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The laser flash photolysis of dodecamethylcyclohexagermane (1) and dimethylphenyl(trimethylsilyl)germane (5), two known photochemical precursors to dimethylgermylene (GeMe2), has been reinvestigated. Laser flash photolysis of 1 in hexane solution affords markedly different results than were reported in an earlier study of this compound in cyclohexane. The present study shows it to yield two primary transient products, one exhibiting λmax = 490 nm and lifetime τ ≤ 10 ns and a second that exhibits λmax = 470 nm and decays on the microsecond time scale with second-order kinetics, with the concomitant growth of absorptions centered at λmax = 370 nm due to tetramethyldigermene (Ge2Me4). The spectrum and absolute rate constants for quenching of the 470 nm species by acetic acid, 2,3-dimethyl-1,3-butadiene (DMB), CCl4, and oxygen in hexane, as well as the transient behavior observed in the presence of millimolar concentrations of THF, are all quite similar to those established recently for GeMe2 using 1-germacyclopent-3-ene derivatives as precursors. Two different transient products dominate the time-resolved spectra obtained from laser flash photolysis of 5 under similar conditions, one exhibiting λmax = 300 nm and τ ≈ 20 μs and a second exhibiting λmax = 430 nm and τ ≈ 4 μs. The latter species was assigned to GeMe2 in earlier studies; it is re-assigned in the present work to the conjugated germene (6) derived from 1,3-trimethylsilyl migration into the ortho-position of the phenyl ring in 5, on the basis of comparisons of the spectrum and absolute rate constants for quenching of the species by oxygen, DMB, CCl4, acetic acid, and acetone to those reported previously for the homologous silene derivative (11) and the corresponding 1,1-diphenyl-substituted analogues of the germene (12) and the silene (13). Weak transient absorptions consistent with the postpulse formation of Ge2Me4 are also detectable from 5 in deoxygenated hexanes, but GeMe2 itself cannot be detected.

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Section: Resultsmentioning

confidence: 99%

Laser Flash Photolysis Studies of Some Dimethylgermylene Precursors

Lollmahomed

Leigh

2009

Organometallics

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“…The final entries in Table represent a collection of structurally authenticated cyclotetragermanes [R 2 Ge] 4 reported in the literature. ,− The photochemistry of octaisopropylcyclotetragermane, [ i Pr 2 Ge] 4 ( 553 ), was investigated recently by laser flash photolysis and accompanying trapping experiments. It was concluded from this study that the ring-opening of [ i Pr 2 Ge] 4 ( 553 ) occurs via a 1,4-biradical intermediate as neither free germylene [:Ge i Pr 2 ] nor the dimeric digermene [ i Pr 2 GeGe i Pr 2 ] could be detected in appreciable amounts, ruling out heterolytic Ge–Ge σ-bond cleavage pathways in this process …”

Section: Inorganic Rings Derived From Group 12–17 Elementsmentioning

confidence: 84%

“…It was concluded from this study that the ringopening of [ i Pr 2 Ge] 4 (553) occurs via a 1,4-biradical intermediate as neither free germylene [:Ge i Pr 2 ] nor the dimeric digermene [ i Pr 2 GeGe i Pr 2 ] could be detected in appreciable amounts, ruling out heterolytic Ge−Ge σ-bond cleavage pathways in this process. 385 The crystal structures of octa-tert-butylcyclotetrastannane, [ t Bu 2 Sn] 4 (560), and octa-tert-amylcyclotetrastannane, [ t Am 2 Sn] 4 (561) ( t Am = CMe 2 Et), were reported in 1986. 386 Treatment of [ t Bu 2 Sn] 4 (560) with I 2 results in ring-opening of the cyclic Sn 4 framework to afford the linear 1,4-diiodoocta-tertbutyltetrastannane, I−(Sn t Bu 2 ) 4 −I.…”

Section: Group 13 Rings Containing Boronmentioning

confidence: 99%

Small Inorganic Rings in the 21st Century: From Fleeting Intermediates to Novel Isolable Entities

et al. 2014

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Germanimum: Organometallic Chemistry

Holl¹,

Peck²

2005

Encyclopedia of Inorganic Chemistry

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This article provides an overview of germanium organometallic chemistry from 1994 to 2007. Major advances in the formation and breaking of GeC bonds are discussed as are advances in the physical characterization of these compounds. Recent advances in the formation of organogermanium species containing multiple bonds to germanium and the formation of germanium‐centered radicals and cations are delineated. Applications to the synthesis of germanium‐containing polymers are overviewed.

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Re-examination of the photochemical reaction of octaisopropylcyclotetragermane

Cited by 4 publications

References 20 publications

Laser Flash Photolysis Studies of Some Dimethylgermylene Precursors

Laser Flash Photolysis Studies of Some Dimethylgermylene Precursors

Small Inorganic Rings in the 21st Century: From Fleeting Intermediates to Novel Isolable Entities

Germanimum: Organometallic Chemistry

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