Intermolecular force effects on geminate combinations

Frisch, H. L.; Kuivila, Henry G.

doi:10.1021/ja00464a017

Cited by 4 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reaction mixture was worked up after 0.5 h by adding water and extracting with petroleum ether. The ether extracts were washed repeatedly with water, then dried (MgS04) and concentrated to yield 0.38 g of crude product: NMR (CDC13) 0.06 (s, Me4Sn), 0.22 (s, 2J(SnCH) = 49 Hz, V(SnSnCH) = 16 Hz, (Me3Sn)2), 0.33 (s, 27(SnCH) not detectable owing to weak resonance, tentatively assigned to ÁrSn(C//3)3), and 1.55 (s, COH(C//3)2, reduction and/or substitution product).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Nucleophilic aromatic substitution by organostannylsodiums. A second-order reaction displaying a solvent cage effect

Wursthorn¹,

Kuivila²,

Smith³

1978

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Results of a study of mechanistic aspects of the reaction of triorganostannylsodiums with halobenzenes are reported. The reaction in tetraglyme, which is first order in each reactant, is unusually fast for an unactivated nucleophilic aromatic substitution, and provides high yields of arylstannanes, R3SnAr. Minor amounts of R3SnAr2 and R4Sn are also formed by a mechanism which is presumed to involve initial dissociation of R3SnNa into (RzSn) and RNa. Reduction product, ArH, is formed when effective proton donors are present in the reaction mixture. ArD is formed when 2-propanol-4 is present, indicating that aryl anions are intermediates. The initial step in the proposed mechanism of the reaction between the aryl halide and organostannylsodium results in the formation of caged species, which may react in the cage to form substitution product, ArSnR3, or diffuse from the cage as ArNa and R3SnX, which may react with each other to form more substitution product or with other species present in the bulk of the solvent. This concept of the mechanism is based on the results of proton trapping, which shows a saturation effect, and on the effect of solvent viscosity on the fractions of ArH and ArSnR3 formed in the presence of tertbutyl alcohol. Study of the course of reactions of trimethylstannylsodium with aryl bromides bearing intramolecular traps such as ketone carbonyls and hydroxyl groups provides support for the mechanism proposed. The order of reactivities of aryl halides is Arl > ArBr > ArCl > ArF.

show abstract

Section: Methodsmentioning

confidence: 99%

“…In fact, if one assumes that the field between the particles is very strong compared with thermal fluctuation forces leading to diffusion a different relationship would apply. 16 As shown in eq 2 the dependence of the yield function is on the reciprocal of the cube root of the product of viscosity and dielectric constant. A test of the relationships 2a and…”

mentioning

confidence: 99%

Nucleophilic aromatic substitution by organostannylsodiums. A second-order reaction displaying a solvent cage effect

Wursthorn¹,

Kuivila²,

Smith³

1978

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

ChemInform Abstract: INTERMOLECULAR FORCE EFFECTS ON GEMINATE COMBINATIONS

Frisch¹,

Kuivila²

1978

Chemischer Informationsdienst

View full text Add to dashboard Cite

Analyses of In-Cage Singlet Radical-Pair Motions from Irradiations of 1-Naphthyl (R)-1-Phenylethyl Ether and 1-Naphthyl (R)-2-Phenylpropanoate in n-Alkanes

Weiss

2005

J. Org. Chem.

View full text Add to dashboard Cite

[reaction: see text] The regio- and stereochemistries of photo-Claisen reactions of 1-naphthyl (R)-1-phenylethyl ether ((R)-2), in combination with photo-Fries and photo-Claisen-type reactions of 1-naphthyl (R)-2-phenylpropanoate ((R)-1), have been investigated in n-alkanes of different viscosities and at several temperatures. Analyses of the results provide detailed information about the in-cage motions of the singlet prochiral 1-naphthoxy/1-phenylethyl radical pairs (radical-pair B) that are formed directly from (R)-2 and indirectly from (R)-1 via decarbonylation of singlet chiral 1-naphthoxy/2-phenylpropanoyl radical pairs (radical-pair A). In hexane at 23 degrees C, the photo-Claisen products from irradiations of (R)-2 retain up to 31% enantiomeric excess (ee), but the ees of the same photoproducts from (R)-1 are near 0%. This disparity is attributed to differences between the initial orientations of the constituent radicals of radical-pair B at the moment of their "birth". The regio- and stereoselectivities reach plateau values as the solvent viscosity increases, indicating that the relationships between the rates of radical-radical bond formation and either translational or tumbling motions within a solvent cage reach an asymptotic limit. Detailed analyses are presented of the various motions that are in competition within a solvent cage during the very short lifetimes of the radical pairs. The data, in toto, present interesting insights into how radical pairs move during short periods and over short distances when their solvent cages have walls of varying flexibility.

show abstract

Intermolecular force effects on geminate combinations

Cited by 4 publications

References 3 publications

Nucleophilic aromatic substitution by organostannylsodiums. A second-order reaction displaying a solvent cage effect

Nucleophilic aromatic substitution by organostannylsodiums. A second-order reaction displaying a solvent cage effect

ChemInform Abstract: INTERMOLECULAR FORCE EFFECTS ON GEMINATE COMBINATIONS

Analyses of In-Cage Singlet Radical-Pair Motions from Irradiations of 1-Naphthyl (R)-1-Phenylethyl Ether and 1-Naphthyl (R)-2-Phenylpropanoate in n-Alkanes

Contact Info

Product

Resources

About