Ethylene tetraphenyl

METHYL-, HYDROCHLORIDE, 31, 37 Ethyl benzolacetate, 32, 85 O-Ethylcaprolactim, 31, 73 Ethyl chloroacetate, 30, 7 Ethyl /9-chloroisocrotonate, 32, 78 Ethyl cyanoacetate, 32, 45 Ethyl dichloroacetate, 32, 47 Ethylene, 32, 100 Ethylene, tetraphenyl-, 31,104... 

METHYL-, HYDROCHLORIDE, 31, 37 N-methyl-1,2-diphenyl-, 34, 64 Ethyl benzoylacetate, 32, 85 Ethyl bromide, 34, 58 O-Ethylcaprolactim, 31, 73 Ethyl chloroacetate, 30, 7 34, 54 Ethyl chloropluoroacetate, 34, 49 Ethyl /3-chloroisocrotonate, 32, 78 Ethyl cyanoacetate, 32, 45 Ethyl dichloroacetate, 32, 47 Ethyl enanthylsuccinate, 34, 51 Ethylene, 32, 100 Ethylene, tetraphenyl-, 31,104 Ethylene chloride, 34, 85, 86 Ethylene chlorohydrin, 30, 11 33, 11 Ethylene dibromide, 30, 35 Ethylene diisothiuronium bromide, 30, 36... 

Ethylene, tetraphenyl-, 31,104 Ethylenimine, 30, 38 toxic properties of, 30, 40 Ethyl glycidyl ether, 31, 3 Ethyl iodide, 31, 34 Ethyl lactate, 31, 59, 60 5-Ethyl-2-methylpyridine, 30, 41 Ethyl phenylcyanoacetate, 30, 43, 80... 

Whether the second step does take place depends on a number of factors. The electron affinity of the M ion must be sufficiently great, and this point can be appreciated by considering a few examples. Electron transfer to stilbene or tetraphenyl ethylene leads to the formation of negative ions which in turn rapidly ac-... 

In fact, the stabilization of the diion formed from tetraphenyl ethylene is so great that the monoion cannot be isolated. On the other hand, the stabilization of the diion of stilbene is less pronounced, and hence both the monoionic and the diionic species are observed. In contrast to these cases, the addition of a second electron to the styrene" ion or to the 1,1 diphenyl ethylene- ion would yield a diion possessing one unstabilized end charge, i.e.,... 

Groups of reportedly photochromic systems which deserve further study include (a) disulfoxides (123,124), (b) hydrazones (125-129), (c) osazones (130-133), (d ) semicarbazones (134-143), (e) stilbene derivatives (144), (/) succinic anhydrides (145-148), and (g) various dyes (149,150). A number of individual compounds also remain unclassified as to their mechanism of photochromic activity. These include o-nitro-benzylidine isonicotinic acid hydrazide (151), 2,3-epoxy-2-ethyl-3-phenyl-1-indanone (152), p-diethyl- and p-dimethyl-aminophenyli-minocamphor (153), brucine salts of bromo- and chloro-nitromethionic acid (154), diphenacyldiphenylmethane (155,156), 2,4,4,6-tetraphenyl-1,4,-dihydropyridine (155,156), 2,4,4,6-3,5-dibenzoyltetrahydropyran (155,156), o-nitrobenzylidenedesoxybenzoin (157), p-nitrobenzylidene-desoxybenzoin (157), N-(3-pyridyl)sydnone (158,159), tetrabenzoyl-ethylene (160), and the oxidation product of 2,4,5-triphenylimidazole (161,162). 

Orthoesters. As model experiments (1) phenyl Cellosolve and tetraphenyl orthocarbonate, and (2) hydroxyethyl benzoate and tetra-phenyl orthocarbonate reacted at 275°C. Diphenyl carbonate was obtained from the latter reaction but not from the former. The facts that the distillate from the latter reaction contained ethylene oxide and that diphenyl carbonate was formed quantitatively from the reaction of carboxylic acid and tetraphenyl orthocarbonate suggest the following reaction mechanism ... 

Tetraphenyl dimethylene ditelluronium dibromide lost ethylene on heating forming diphenyl tellurium dibromide11. 

According to Wittig and Lupin,160 the cyclic peroxide (151) is formed when a suspension of 1,4-dipotassium 1,1,4,4-tetraphenyl-butane in ether is treated with dry oxygen. The peroxide (152) is formed, though in small quantities, during the autoxidation of di-(p-anisyl)ethylene in benzaldehyde, by combination of two molecules of... 

As a rule dipyrylenes are characterized by chemical and thermal stability, but under special conditions cleavage of the ethylene bond can be achieved. Thus, on heating with thionyl chloride followed by treatment with water, the tetraphenyl derivative (52c) is converted into 2,6-diphenyl-4l/-pyran-4-one.50,108 Only decomposition products were isolated with the corresponding methoxyphenyl derivative (52d). 

Duboisia samples have been analysed for scopolamine and hyoscyamine, using g.l.c. by a slope ratio method and by methods employing homatropine, tetraphenyl-ethylene, and phenylacetyltropine as internal standards. The alkaloids were converted into their trimethylsilyl ethers with hexamethyldisilazane scopolamine was the major component, followed by hyoscyamine and norhyoscyamine, meteloidine, phenylacetyltropeine, and valeroidine, tigloidine, valtropine, butropine, and acetyl-tropine, together with some anabasine and nicotine as non-tropane bases. 

Reaction with diazo compounds. Trilyl perchlorate Is a very efficient catalyst for the decomposition of diphenyidiazomethane with dimerization to tetraphenyl-ethylene. The reagent reacts with ethyl diazoacetate in acetonitrile to give ethyl... 

CrO -AciO-AcOH. This reagent, diacetyl chromate, oxidizes tetraphenyl-ethylene largely to benzopinacol carbonate and tetraphenylethylene oxide, with a minor amount of benzophenone. ... 

The same ylide reacts analogously, but less effectively when exposed to benzonitrile oxide 4,4-ethylene-3,5,5,5-tetraphenyl-l,2,5-oxazaphospholidine was obtained in 61% yield.This heterocycle is unstable when treated with iodomethane. 

What we consider as the first unequivocal evidence for such an insertion reaction has now been demonstrated by D. A. Bright and A. M. Aaronson (24). Under carefully controlled conditions, they added ethylene oxide to tetraphenyl pyrophosphate to form and to identify as the sole reaction product ethylene glycol bis (diphenyl phosphate). This is illustrated in Fig. 8. The reaction proceeds at 70 °C when ethylene oxide is added to molten... 

Figure 9. An evaluation of the response of the photodiode arrays signal as a function of light intensity of 50ps duration. The light intensity was varied with a neutral density filter. The light was created by exciting a solution of tetraphenyl ethylene in hexane with 30-ps, 355-nm light pulses. This molecule is known to have a fluorescence lifetime of 6 3 ps in these environments.

Wurtz coupling catalyst. Muller and Roscheisen1 noted that low yields in the Wurtz coupling of two molecules of a benzyl halide may be because the reaction proceeds in part at least in heterogeneous phase on the surface of the metal. They found that tetraphenyl ethylene forms a disodium adduct which is sufficiently soluble in THF or glyme for the efficient coupling of 2 moles of benzyl chloride ... 

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