| 摘要 |
<p>A compound having the general formula IN WHICH R1 , R2, R3 and R4 may be the same or different and represent hydrogen, a straight or branched chain alkyl radical having 1 to 20 carbon atoms, an aralkyl radical having 7 to 20 carbon atoms which may be substituted by one or more alkyl groups having 1 to 4 carbon atoms, or may be of the type: WHEREIN R5 and R6 are each a hydrogen atom or a methyl group, and each R represents the others of R1, R2, R3 and R4, an alkenyl radical having 2 to 20 carbon atoms; a cycloalkyl radical having 5 to 12 carbon atoms which may be substituted by one or more alkyl groups having 1 to 4 carbon atoms; an aryl radical having 6 to 10 carbon atoms; an alkaryl radical having 7 to 12 carbon atoms; a cyclohexyl alkyl radical in which the alkyl moiety has 2 or 3 carbon atoms and the cyclohexenyl ring may contain a methyl group as substituent; an alkenyl cyclohexyl radical in which the alkenyl moiety has 2 or 3 carbon atoms and the cyclohexyl ring may also contain a methyl group as substituent; or a group -OR7 wherein R7 represents an alkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 5 to 12 carbon atoms, optionally substituted by one or more alkyl groups having 1 to 4 carbon atoms, an aryl radical having 6 to 10 carbon atoms or an alkenyl radical having 3 to 20 carbon atoms; or any two adjacent radicals R1, R2, R3 and R4 may be joined together to form an aryl ring which may be substituted by one or more alkyl groups having 1 to 20 carbon atoms; X represents an anion; and n is the valency of X, is useful for the extraction of metals from aqueous solutions.</p> |
