Medium effects and quantum yields in the photoaddition of naphthalene and acrylonitrile. Chemical evidence on an exciplex structure

Bowman, R. M.; Chamberlain, T. R.; Huang, Chung-Chi; McCullough, John J.

doi:10.1021/ja00810a010

Cited by 47 publications

(28 citation statements)

References 9 publications

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“…Torbional Angles, deg C(l)C(7)C(8)C(9) 4.8 (3) C(l)C(2)0(3)C(4) C(7)C(8)C(9)C( 10) -6.2 (3) C(2)0(3)C(4)C(5) C(8)C(9)C(lO)C(ll) 2.5 (2) 0(3)C(4)C(5)C(1) C(lO)C(ll)C(l)C(7) -3.9 (2) C(5)C(l)C(2)0(3) C(9)C(lO)C(ll)C(l) 2.9 ( 2 ) C(4)C(5)C(l)C(2) C(ll)C(l)C(7)C (8) 0.0 (2) C( l)C(5)C(6)CU) C( 5)C(6)C( 7)C( 1 ) C(6)C(7)C(l)C(5) C(7)C( 1)45)C (6) 41.1 (2) -41.1 ( 2 ) 23.7 (2) 1.0 (2) -25.2 (2) -0.9 (2) -0.9 (2) 0.9 (2) 0.9 (2)…”

Section: Discussionunclassified

Naphthonitrile-alkene exciplexes. Comparison of bimolecular and bichromophoric cases: effects of linking on fluorescence and photochemistry

McCullough¹,

MacInnis²,

Lock³

et al. 1982

J. Am. Chem. Soc.

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The fluorescence quenching and photochemistry of 2-methyl-, 4-methyl-, and 6-methyl-1-naphthonitrile with tetramethylethylene have been studied in nonpolar solvents. Stern-Volmer constants (benzene solvent) are 10.1, 15.7, and 7.2 M-', respectively, showing that quenching is insensitive to the position of the methyl group. Exciplex emission was observed in each case, and exciplex lifetimes were measured by single photon counting techniques. The methylnaphthonitriles react with tetramethylethylene to give 1-cyano-7,7,8,8-tetramethyl-2,3-benzobicyclo[4.2.0] -2,4-octadiene derivatives, and limiting quantum yields were measured. In the case of 4-methyl-l-naphthonitrile, quenching with biacetyl showed that the exciplex is an intermediate in the cycloaddition reaction and no triplets are formed in the exciplex decay. Rates of exciplex collapse to cyclobutane products were derived. The bichromophoric molecules 1, 2, and 3, in which the chromophores are linked by a three-atom chain, were synthesized. All three show strong quenching of the monomer (naphthonitrile) fluorescence, and weak exciplex emission. Compounds 1,2, and 3 also react on irradiation, giving internal cycloaddition products. The structures of the latter were determined, and the structure work is described. Comparison of quantum yields for internal cycloaddition with limiting quantum yields for the bimolecular cases shows that the three-atom chain greatly facilitates collapse of the exciplexes to products in these systems. Exciplex formation and decay are discussed in terms of current theory. The structure of one photoproduct, 7-cyano-5,6,6-trimethyl-8,9-benzo-3-oxatricyclo[S.4.O.O1~5]-8,lO-undecadiene (lo), was determined by X-ray diffraction. and the structure is described.Exciplex formation was proposed some time ago by Hammond and co-workers2 to account for the quenching of fluorescence of aromatic compounds by dienes.2 The observation of exciplex fluorescence from 1 -naphthonitrile and electron-rich alkenes by Taylor3 showed that exciplexes are indeed formed in fluorescence quenching by ethylene derivatives. A kinetic analysis of the 1-naphthonitrile-olefin system has been carried o~t .~,~ Exciplex formation was found to be reversible, and rate constants for the ( I ) (a) Department

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Section: Discussionunclassified

Naphthonitrile-alkene exciplexes. Comparison of bimolecular and bichromophoric cases: effects of linking on fluorescence and photochemistry

McCullough¹,

MacInnis²,

Lock³

et al. 1982

J. Am. Chem. Soc.

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“…This is to be compared with the case of the cycloaddition reaction of acrylonitrile with a-and Pnaphthols and their trimethylsilyl ethers. In these cases, the regioselectivity is governed by the position of the oxygen substituent (8). In our cases, the position of the naphthalene substituent does not affect the regioselectivity.…”

Section: Discussionmentioning

confidence: 51%

“…In the 'H spectrum the 5-and 6-hydrogen signals both appear as double doublets, coupled to each other, and separately to the 4-proton, as found in other related photoproducts containing the dihydronaphthalene skeleton (6)(7)(8). Of the hydrogens in the 11-and 12-methylene groups, one proton signal lies at a lower field than any of the others, and is assigned to the 12-exo hydrogen as it is in the deshielding zone of the fused benzene ring.…”

Section: Photochemical Rearrangementsmentioning

confidence: 59%

Photochemistry of substituted cyclic enones. Part 6. Photochemical reactions of 5-arylmethyl-3-phenylcyclopent-2-enones. A photostationary state

Clements¹,

McMurry²

1987

Can. J. Chem.

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. Can. J. Chem. 65, 18 10 (1987).Photolysis of 5-(1-and 2-naphthylmethy1)-3-phenylcyclopent-2-ens affords [2 + 21 cycloaddition products, the 7,8-and 5,6-benzo-fused l0-phenyltetracyclo[7.2.1.03~10.04~9]dodeca-5,7-dien-2-ones respectively, in equilibrium with the starting enones. A similar dibenzo-fused photoproduct is formed from the corresponding 9-phenanthrylmethyl substituted cyclopentenone. The photoproducts revert to the respective enones on acid treatment, or pyrolysis, and on photolysis. La photolyse des (naphtyl-1 ou -2 methyl)-5 phenyl-3 cyclopentine-2 ones conduit i des produits de cycloadditions [2 + 21, soit respectivement les benzo-7,8 ou -5,6 phenyl-10 tttracyclo[7.2.1 .03.10.04.9] dodCcadi&ne-5,7 ones-2, qui sont en tquilibre avec les Cnones de depart. Si l'on part de la cyclopent~none correspondante substitute par une phtnanthryl-9 mtthyle, il se forme un photoproduit similaire qui est fusionni i un dibenzo. Par traitement avec des acides, par pyrolyse ou par photolyse, les photoproduits se retransforment dans leurs hones respectives.[Traduit par la revue]In recent publications (1, 3, 4) we have described the photochemical intramolecular cyclisation of 5-ally1 and substituted 5-allylcyclopentenones. In all these cases the reactions were regiospecific, as far as the direction of addition, but in the case of the compounds with cinnamyl side chains there was loss of stereoselectivity of the phenyl substituent. We wished to discover whether aromatic "double bonds" could be incorporated into cycloaddition products and, if so, whether the regiospecificity would be affected. Furthermore, to our knowledge, no example is known where enone adds onto a naphthalene ring although, where two naphthalene rings are linked by a suitable chain, then photoaddition of the two rings is found (5). SvnthesisThe 5-arylmethyl-3-phenylcyclopentenones were synthesised by standard routes (Scheme 1). The ring closure of the diketo esters involves the hydrolysis of the ester and decarboxylation of the keto acid, followed by cyclisation of the resultant 1,5-diketone. In this way, 5-benzyl-, 5-(1-naphthylmethy1)-, 5-(2-naphthylmethy1)-, and 5-(9-phenanthrylmethy1)-3-phenylcyclopentenones (la-d) were prepared.

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“…90% yeild. Refluxing of the adduct (2) with potassium tert-butoxide in tert-butanol (the conditions used by McCullough et al) afforded 2-carbamoy1-1,2-dihydrocyclobuta[a]naphthalene (4) in ca. 20% yield.…”

Section: Synthesis Of 2-cyano-12-dihydrocyclobuta[a]naphthalene and mentioning

confidence: 99%

“…Hence, we first re-examined the base-catalyzed elimination of methanol from the adduct (2). As a result, it was found that use of dry benzene instead of tert-butanol as a solvent, and a reduction in the reaction time, resulted in a satisfactory result.…”

Section: Synthesis Of 2-cyano-12-dihydrocyclobuta[a]naphthalene and mentioning

confidence: 99%

Cycloadditions in syntheses. XXXV. 2-Cyano-1,2-dihydrocyclobuta[a]naphthalene and its derivatives: synthesis and reaction with olefins.

Sato

Suzuki

Morisawa

et al. 1987

CHEMICAL & PHARMACEUTICAL BULLETIN

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Medium effects and quantum yields in the photoaddition of naphthalene and acrylonitrile. Chemical evidence on an exciplex structure

Cited by 47 publications

References 9 publications

Naphthonitrile-alkene exciplexes. Comparison of bimolecular and bichromophoric cases: effects of linking on fluorescence and photochemistry

Naphthonitrile-alkene exciplexes. Comparison of bimolecular and bichromophoric cases: effects of linking on fluorescence and photochemistry

Photochemistry of substituted cyclic enones. Part 6. Photochemical reactions of 5-arylmethyl-3-phenylcyclopent-2-enones. A photostationary state

Cycloadditions in syntheses. XXXV. 2-Cyano-1,2-dihydrocyclobuta[a]naphthalene and its derivatives: synthesis and reaction with olefins.

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