Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Photoelimination from Organohalogen Compounds

2 Photoeliminations from Organohalogen Compounds. The 4-band photodissociation of methyl iodide to CH3 and I fragments has been studied in detail [Pg.314]

Multiphoton dissociation of CHsBr at 248 and 193 nm generates electronically excited CH( 4 and the quenching of this species by alcohol, [Pg.315]

Isotope-selective IR multiphoton photodissociation of CF3I has been examined as a means of achieving C enrichment, and about 400-fold enrichment has been reported following a single laser pulse in a short-path gas dynamic flow system. Multiphoton IR dissociation of CHCIF2 has been shown to [Pg.315]

Studies of the photodissociation dynamics of chlorinated benzene derivatives have been reviewed. Photodissociation of chlorobenzene at 266 nm has been investigated by the crossed laser-molecular beam technique, and a hot molecule mechanism is considered probable. Similar studies have been carried out for bromobenzene and p-bromotoluene, which show that for each of these molecules the dissociation is fast and the transition dipole moment is almost perpendicular to the C-Br bond. In deoxygenated aqueous solutions, 254 nm photolysis of chlorobenzene yields phenol and chloride ions as the main products, along with benzene, phenylphenols and biphenyl.lodo-benzene adsorbed on sapphire(OOOl) at 110 K undergoes C-I bond cleavage when irradiated at 193 nm.  [Pg.317]

Photolysis of 5-chloro-2-hydroxybenzonitrile (70) in aqueous solution gives the triplet carbene (71), which can be detected by transient absorption spectroscopy (X,max at 368 and 385 nm). The carbene was recognized by its reactions, e.g. with O2, to produce the corresponding carbonyl O-oxide (A ax at 470 nm), and with propan-2-ol to give 2-cyanophenoxyl radical. In deoxygenated solutions the main stable products are 2,5-dihydroxybenzonitriIe and two substituted biphenyls. [Pg.317]

2 Photoeliminations from Organohalogen Compounds. - A theoretical study [Pg.189]

The IR multiphoton dissociation of CF3H, pre-excited to the second C-H stretch overtone, has been examined with a view to developing a laser isotope-separation method for C. This single stage process resulted in a C2F4 product [Pg.191]

The allyl cation (CH2 = CHCH2 ) has been observed by resonance Raman spectroscopy following UV photodissociation of cyclopropyl bromide in acetonitrile.  [Pg.193]

As reported in Section 2 above, an attempt to use the pyrazolinedione (5) as a photochemical source of difluorocarbene failed on account of the instability of [Pg.193]

The photodissociation of bromobenzene in solution has been investigated with ultrafast transient absorption spectroscopy, following excitation at 266 nm. The main kinetic feature in acetonitrile was a 9 ps decay that was assigned to predissociation similar decays were observed in hexane, dichloromethane and tetrachloromethane. Laser-aligned iodobenzene have been photodissociated into phenyl radicals and iodine atoms with a 1.5 ps laser pulse at 266 nm, and the yield of iodine photoproducts detected by resonant multiphoton ionization. Significant yield enhancements were observed when the dissociation laser was polarized parallel instead of perpendicular to the alignment laser polarization. [Pg.193]


Photoeliminations from Organohalogen Compounds. A review has been published of the photobehaviour of alkyl, aryl, benzylic and homobenzylic halides in solution and of alkyl halides in the gas phase. ... [Pg.220]




SEARCH



Organohalogen

Organohalogen compounds

Organohalogenated compounds

Photoeliminations from Organohalogen Compounds

Photoeliminations from Organohalogen Compounds

Photoeliminator

© 2024 chempedia.info