129399-45-7

Upstream product

• 768-60-5 4-methoxyphenylacetylen 

Downstream Products

• 129399-46-8 1-Methoxy-4-[1-(2,2,2-trifluoro-ethoxy)-vinyl]-benzene 

Relevant academic research and scientific papers

Study of the time-resolved IR spectrum of α-arylvinyl cations generated by laser flash photolysis

The characteristic stretching band of the C(sp2)=C(sp)+ moiety in vinyl cations was observed for the first time around 1870 cm-1 by a time-resolved IR spectrometry with 266 nm or 308 nm laser flash irradiation of (4-methoxyphenyl)alkynes in TFE and α-arylvinyl bromide in acetonitrile. The ultraviolet-visible and the IR absorption maxima were affected by the β-substituents.

The generation of vinyl cations and excited triplet states by laser flash irradiation of arylalkynes

Laser flash photolysis of 4-methoxyphenyl (anisyl) substituted alkynes 1 in protic and aprotic solvents was investigated in order to study the generation of the α-anisylvinyl cations 2 by laser flash photoprotonation of the arylalkynes. Cations 2 were generated in 2,2,2-trifluoroethanol, but the excited triplet state of arylalkyne 1 was detected in the aprotic solvents dichloromethane and acetonitrile. Reaction of the cations 2 with sodium azide was investigated and found to be diffusion controlled; reactions of 2 with cyclohexa-1,3-diene were also investigated and found to be appreciably affected by steric hindrance due to the β-substituents. Copyright

Lifetimes and UV-visible absorption spectra of benzyl, phenethyl, and cumyl carbocations and corresponding vinyl cations. A laser flash photolysis study

Benzyl (4-MeO, 4-Me, and 4-methoxy-1-naphthylmethyl), phenethyl (4- Me2N, 4-MeO, 3,4-(MeO)2, 4-Me, 3-Me, 4-F, 3-MeO, 2,6-Me2, parent, and 4- methoxy-1-naphthylethyl) and cumyl (4-Me2N, 4-MeO, 4-Me, parent) cations have been studied by laser flash photolysis (LFP) in 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP). In most cases styrene or α-methylstyrene precursors were employed for the phenethyl and cumyl ions, the intermediate being obtained by solvent protonation of the excited state. Benzyl cations were generated by photoheterolysis of trimethylammonium and chloride precursors. While a 4-MeO substituent provides sufficient stabilization to permit observation of cations in TFE, cations with less stabilizing substituents usually require the less nucleophilic HFIP. Even in this solvent, the parent benzyl cation is too short-lived (lifetime 6H4C+(R)-CH3 (R = Me, Et, i-Pr, t-Bu, cyclopropyl, C6H5, 4-MeOC6H4) were generated in TFE via the photoprotonation route. The alkyl series shows that steric effects are important in the decay reaction. The cation with R = cyclopropyl is a factor of 1.5 less reactive than the cation where R = phenyl. Several vinyl cations have also been generated by photoprotonation of phenylacetylenes. ArC+=CH2 has a reactivity very similar to that of its analog ArC+H-CH3, the vinyl cation being slightly (factors of 2-5) shorter-lived. For the various series of cations, including vinyl, substituents in the aryl ring have a consistent effect on the κ(max), a shift to higher wavelength relative to hydrogen of 15 nm for 4-Me, 30 nm for 4-MeO, and 50 nm for 4-Me2N.

LASER FLASH PHOTOLYSIS OBSERVATION OF THE 1-p-METHOXYPHENYLVINYL CATION BY PHOTOPROTONATION OF p-METHOXYPHENYLACETYLENE. COMPARISON WITH THE 1-p-METHOXYPHENETHYL CATION.

Photolysis of p-methoxyphenylacetylene in trifluoroethanol results in transient 1-p-methpoxyphenylvinyl cation 7 which has been detected by laser flash photolysis (λ = 248 nm).This cation shows remarkably similar behaviour to the 1-p-methoxyphenethyl cati