. . . . . "Typically, such salts are derived from compounds of the formula ##STR28## wherein each of R1, R2, R3, R4, R5 and R6 is a hydrogen atom or a carbon-bonded organic group such as a hydrocarbyl group or a substituted hydrocarbyl group wherein the substituent(s) do(es) not materially detract from the predominantly hydrocarbonaceous character of the hydrocarbyl group; X is a sulfur or an oxygen atom and" . . . . . .