Photosolvolysis of 9-fluorenol derivatives in aqueous solution—exploratory studies of reactivity of photogenerated 9-fluorenyl cations

Blazek, Almira; Pungente, Michael D.; Krogh, Erik; Wan, Peter

doi:10.1016/1010-6030(92)85006-g

Cited by 15 publications

(12 citation statements)

References 10 publications

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“…This was confirmed by analyzing the authentic olefin by SEC as a reference compound. Although the compounds showing other low‐molecular‐weight peaks in SEC have not yet been identified, they could contain photo reaction products obtained from the olefin 12, 13…”

Section: Resultsmentioning

confidence: 99%

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A photo‐degradable helix: Synthesis, structure, and photolysis of optically active poly[2,7‐bis(4‐t‐butylphenyl)‐9‐methylfluoren‐9‐yl acrylate]

Sakamoto¹,

Watanabe²,

Shichibu³

et al. 2010

J. Polym. Sci. A Polym. Chem.

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2,7-Bis(4-t-butylphenyl)-9-methylfluoren-9-yl acrylate (BBPMFA) was synthesized and polymerized using a,a 0 -azobisisobutyronitrile or n-Bu 3 B-air as a radical initiator and using the complex of 9-fluorenyllithium with (S)-(þ)-1-(2-pyrrolidinylmethyl)pyrrolidine as an optically active anionic initiator. Although the radical polymerization led to rather low-molecular-weight products at low yields, the anionic polymerization afforded polymers with higher molecular weights in higher yields. The poly(BBPMFA) obtained by the anionic polymerization was slightly rich in isotacticity (meso diad 57%) and showed an intense circular dichroism (CD) spectrum and large dextrorotation. The intensity of the CD spectrum and magnitude of optical activity increased with an increase in M n , suggesting that the polymer possesses a preferred-handed helical conformation. The CD spectrum disappeared within 1 s on irradiation to the polymer in a CHCl 3 solution using a 500-W Hg-Xe lamp. This was ascribed to fast photolysis of the ester linkage leading to a loss of helical conformation of the entire chain. Photolysis products of poly(BBPMFA) were poly(acrylic acid) and 2,7bis(4-t-butylphenyl)-9-methylenefluorene (2,7-bis(4-t-butylphenyl)dibenzofulvene). The photolysis reaction seemed to proceed through the ''unzipping'' mechanism. The rate constant of photolysis of poly(BBPMFA) under irradiation at monochromated 325 nm was around 0.01 s À1 independent of molecular weight. Photolysis at 325 nm was approximately 2400 times faster than that for chemical ester solvolysis under a neutral condition in the dark. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: [945][946][947][948][949][950][951][952][953][954][955][956] 2011

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Section: Resultsmentioning

confidence: 99%

“…Based on these results, the products of the polymer photolysis are reasonably identified as a mixture of the olefin and poly (acrylic acid) (Scheme ). Photolysis of 9‐methyl‐ or 9‐alkylfluorene derivatives leading to olefin compounds has been reported 12, 13. The intermediates of such reactions have been proposed to be a fluorenyl cation.…”

Section: Resultsmentioning

confidence: 99%

A photo‐degradable helix: Synthesis, structure, and photolysis of optically active poly[2,7‐bis(4‐t‐butylphenyl)‐9‐methylfluoren‐9‐yl acrylate]

Sakamoto¹,

Watanabe²,

Shichibu³

et al. 2010

J. Polym. Sci. A Polym. Chem.

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“…[17][18][19][20] They also reported that C9-OH cleavage can occur both via photohomolysis and -heterolysis (Scheme 1), while the ratio between F and F + depends on the dielectric constant of the solvent. 16,21 Later, the focus of this topic shifted to the characterization of these two intermediates. 16,[22][23][24] Of particular interest was the lifetime of the cation and its stability in different solvents.…”

Section: Introductionmentioning

confidence: 99%

A long-lived fluorenyl cation: efficiency booster for uncaging and photobase properties

Abdellaoui

Hermanns

Reinfelds

et al. 2022

Phys. Chem. Chem. Phys.

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“…Thus, we chose to look at the possibility of alkyl migration via the photochemistry of oxiranes (5)(6)(7). Constraining the C-O bond to a dihedral angle relative to the two aryl systems, oxiranes 5-7 provide reasonable assurance of overlap between the photoexcitable π-systems and the C-O* orbital.…”

mentioning

confidence: 99%

“…Photolysis in hexane at 254 nm showed that 3Ј,3Ј-dimethylspiro[9H-fluorene-9,2Јoxirane] 5 7 was quite reactive and with Scheme 1 short reaction times (5-10 min) produced a single product. Analysis of the reaction mixture showed that the sole product was ketone 8, the expected product of a photochemically induced 1,2-methyl migration.…”

mentioning

confidence: 99%

Photochemistry of aryloxiranes: free radical 1,2-alkyl migrations in a constrained system

Arney

White

Ramanathan

et al. 2004

Photochem Photobiol Sci

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Photosolvolysis of 9-fluorenol derivatives in aqueous solution—exploratory studies of reactivity of photogenerated 9-fluorenyl cations

Cited by 15 publications

References 10 publications

A photo‐degradable helix: Synthesis, structure, and photolysis of optically active poly[2,7‐bis(4‐t‐butylphenyl)‐9‐methylfluoren‐9‐yl acrylate]

A photo‐degradable helix: Synthesis, structure, and photolysis of optically active poly[2,7‐bis(4‐t‐butylphenyl)‐9‐methylfluoren‐9‐yl acrylate]

A long-lived fluorenyl cation: efficiency booster for uncaging and photobase properties

Photochemistry of aryloxiranes: free radical 1,2-alkyl migrations in a constrained system

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