Calculation of Acidity Constants of Protonated Weak Organic Bases by a New Method, III* Ethers

Abstract

Abstract It is shown in this paper that a consistent set of values of pKBH⁺ for 24 ethers, in good agreement with the few which have been obtained by other methods, can be calculated from a correlation of the HCl solubility in the ethers with ∑σI of the R groups, and also with the gas phase I.P.'s of the ethers. We find that in solution the order of basicity is ROH>R2O>H2O whereas in the gas phase it is R2O>ROH>H2O. Evidence for complete H+ transfer to R2O is deduced for most cases, but a H-bonding "basicity" occurs for the less basic ethers. A brief review of previously obtained pKBH⁺'s for some ethers, MeOH, and H2O is also presented.