Results

101 - 123 of 123
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Phenylchlorocarbenes, produced by photolysis of the parent diazirines, have a very limited lifetime in alkane solvents. The rate of disappearance of p-methyl- and p-chlorophenylchlorocarbenes has been measured in iso-octane, cyclohexane and n-hexane as well as in benzene for comparison. The rate con...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
When photolysis of arylchlorodiazirines is performed in the presence of either alkyl- or allyl-substituted amines, either N-alkyl- or N-allyl-substituted amines result as the sole high-yield (64-93%) products. Photolysis in the presence of phenylallylamine produces a rearranged product in poor yield...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
The formation of a metastable carbene-diazirine ylide (CDY), characterized by an UV absorption spectrum in the range of 270-290 nm and yielding azine by rearrangement, is shown to be a general process in the photolysis of diazirines. However, the yield of formation and the lifetime of CDY greatly de...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Laser flash photolysis studies on alpha-methylbenzylchlorodiazirine, n-propylchlorodiazirine, and isopropylchlorodiazirine have been carried out at low temperatures, ranging from 170 to 230 K. The present results, together with those previously obtained with benzylchlorodiazirine and methylchlorodia...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
3-Substituted indolizines have been obtained in a one-step procedure from the reaction of chlorocarbenes with 2-vinylpyridine.
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
The stereochemistry of 1,2-H migration in ethylchlorocarbene (1) and chloromethylchlorocarbene (2) has been studied by ab initio methods. Geometries of the ground and transition states of a conformational equilibrium and the 1,2 rearrangement were optimized at the DFT (B3LYP) and MP2 levels of theor...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
An ultraviolet photoelectron (PE) spectrometer apparatus that utilizes a tuneable 50 W CW CO2 laser as a directed heat source was used to study the vacuum pyrolysis of diazoacetophenone (la) and its p-methyl, p-methoxy, p-chloro, and p-nitro analogues Ib, Ic, Id, and le. Analysis of the pyrolysate w...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
The first direct determination of a 1,2-chlorine atom shift in a chlorobenzylcarbene was achieved by nanosecond laser flash photolysis. Arrhenius activation parameters of E(act) = 3.39 +/- 0.14 kcal mol-1 and log [A(s-1)] = 10.98 +/- 0.14 were obtained for 1,2-chlorine migration in alpha-methyl-alph...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
Nanosecond laser flash photolysis (lambda = 355 nm) of an aqueous solution of 3-chloro-3-p-chlorophenyldiazirine in isooctane produces a transient absorption at 310 nm due to the formation of the carbene: In the presence of 2-vinylpyridine, a second transient with a broad absorption band peaking at ...
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]
The rate constant for the reaction of benzylchlorocarbene with HCl is 4.7 x 10(9) dm3 mol-1 s-1.
[Page generation failure. The bibliography processor requires a browser with Javascript enabled.]