INVESTIGATION OF SOME TETRAMETHYLGUANIDINIUM SALTS

Tetramethylguanidium perchlorate and nitrate have been prepared and purified. Solutions of the fluoride salt have also been prepared but this salt spontaneously decomposes to the bifluoride salt upon drying. Osmotic and activity coefficients are reported for the perchlorate, nitrate, and fluoride salts. Raman spectral data are also presented for the perchlorate salt. Both types of data indicate that the perchlorate is essentially completely associated in aqueous solutions more concentrated than 1.5-2.0 m. Raman spectra of the perchlorate anion show it to be extremely insensitive to association although the bands in the NH2 stretching region of the salt are almost completely absent. Structures with bridging protons are proposed for the perchlorate and bifluoride salts to account for this behavior. © 1979 American Chemical Society.