Propyl ions, decomposition

The yields calculated using these assumptions are in satisfactory agreement with the experimental values, as illustrated in Table 18. The observation that, among all the fragmentation processes induced by the decay, only reaction (27) is prevented by collisional deactivation, supports the view that the excitation level of the propyl ions that dissociate at 10 torr into allyl ions is low indeed, and that such decomposition is possible for its low energetic requirements. The situation is completely different in the liquid phase. This is indicated, in the first place, by the substantial decrease of the yield of HT, which provides a rough indication... 

Kinetic stability of lithium and the lithiated carbons results from film formation which yields protective layers on lithium or on the surfaces of carbonaceous materials, able to conduct lithium ions and to prevent the electrolyte from continuously being reduced film formation at the Li/PC interphase by the reductive decomposition of PC or EC/DMC yielding alkyl-carbonates passivates lithium, in contrast to the situation with DEC where lithium is dissolved to form lithium ethylcarbonate [149]. EMC is superior to DMC as a single solvent, due to better surface film properties at the carbon electrode [151]. However, the quality of films can be increased further by using the mixed solvent EMC/EC, in contrast to the recently proposed solvent methyl propyl carbonate (MPC) which may be used as a single sol-... 

The mechanism of the acid-catalyzed decomposition of 1-alkyltriazolines has been studied <93JOC2097>. The hydrolytic decomposition of these triazolines in aqueous buffers leads predominantly to 1-alkylaziridines with lesser amounts of 2-(alkylamino)ethanol, alkylamines, and acetaldehyde. The rate of hydrolysis of 1-alkyltriazolines is about twice as fast as that of the analogous acyclic 1,3,3-trialkyltriazenes and varies in the order t-butyl > isopropyl > ethyl > butyl > methyl > propyl > benzyl <92JOC6448>. The proposed mechanism, involving rate-limiting formation of a 2-(alkylamino)ethyldiazonium ion, is shown in Scheme 65. A theoretical study ab initio calculation) of the acid-induced decomposition of 4,5-dihydro-l,2,3-triazolines has also been reported <91JA7893>. 

The formation of novel silicon-rich synthetic zeolites has been facilitated by the use of templates, such as large quaternary ammonium cations instead of Na+. For instance, the tetramethylammonium cation, [(CH3)4N], is used in the synthesis of ZK-4. The aluminosilicate framework condenses around this large cation, which can subsequently be removed by chemical or thermal decomposition. ZSM-5 is produced in a similar way using the tetra-.n-propyl ammonium ion. Only a limited number of large cations can fit into the zeolite framework, and this severely reduces the number of [AIO4] tetrahedra that can be present, producing a silicon-rich structure. 

The rates of losses of C3(H, D)6 from the molecular ions of phenyl-1-propyl-1, l-d2, phenyl-l-propyl-2, 2-dj and phenyl-1-propyl-3, 3, 3-d3 ether showed that hydrogen randomisation did not precede decomposition in the time range from 10ps to 10 ps [86], The losses were initiated by hydrogen transfers from C-l, C-2 or C-3 of the propyl chain to the oxygen atom and, on the basis of the kinetics, it was suggested that the densities of states of the 4-, 5- and 6-membered cyclic transition states were similar. 

The evidence suggests that 2-propanamine interacts with the protons associated with the framework Fe atoms to form 2-propyl ammonium cations which maintain 2-propanamine in the zeolite to high temperatures. Above approximately 600K, the decomposition rate for these cations to form propene and ammonia becomes appreciable. The decomposition reaction is very similar to the Hofmann elimination reaction found for quaternary ammonium salts and provides indirect evidence that ammonium ions are involved in the reaction. When Fe is removed from the framework of the molecular sieve, the associated proton site is lost, along with the capability for forming the ammonium ion and carrying out the reaction at that site. 

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