| abstract |
A compound of structural formula V: ** Formula ** in which M is chosen from the group consisting of (+) - camphor-10-sulfonic acid, 2,2-dichloroacetic acid, 2-hydroxyethanesulfonic acid, acetic acid, aspartic acid benzenesulfonic acid, citric acid, cyclamic acid, di (tert-butyl) naphthalenesulfonic acid, dodecyl sulfonic acid, ethanesulfonic acid, formic acid, fumaric acid, glutamic acid, glycerophosphoric acid, glycine, hydroboric acid, hydrobromic acid, hydrochloric acid, lactic, maleic acid, malic acid, methanesulfonic acid, naphthalene-2-sulfonic acid, nitric acid, oxalic acid, phosphoric acid, p-toluenesulfonic acid, pyruvic acid, saccharin, succinic acid, sulfuric acid, tartaric acid and thiocyanic acid; to a fractional or integer number between about 0.5 and about 3.5, inclusive; and b is a fractional or integer number between about 0 and about 5, inclusive. |