M. Hojo, T. Ueda, M. Yamasaki
May 29, 1999
Citations
0
Influential Citations
20
Citations
Journal
The Journal of organic chemistry
Abstract
M + or M 2+ . In the present paper, we report on observation by 1 H NMR of the formation of stable carbocations from 4-methoxy-substituted trityl chlorides ((4-MeOC6H4)nPh3-nCCl) at higher concentrations, i.e., a preparative level, in the presence of alkali metal and alkaline earth metal perchlorates in acetonitrile at 25 °C. The carbocations are isolated as perchlorate salts from acetonitrile solutions. Metal precipitates formed in the solution are characterized by chemical and instrumental analyses, and a novel salt, BaCl + ClO4 - , is proposed. Also, if carbocations are stabilized in the presence of alkali metal and alkaline earth metal ions, solvolysis reaction rates in SN1 should be promoted. This hypothesis has been verified by the exponential increases in SN1 solvolysis rates of aliphatic halides in the presence of metal salts. 3 We have proposed that “isolated” water molecules (HOH), which are converted from bulk waters by concentrated salts, may behave just like “ethers” (ROR). The main purpose of the present study is to definitively demonstrate that alkali metal and alkaline earth metal ions can take part directly in the chemical reactions in solution. The NMR spectra of triarylmethyl cations have been reported by Moodie et al. 4 The conformational equilibria in trityl cations have been established by 19 F NMR studies. 5 The reversible reaction of trityl tetrafluoroborate