CH2???CH2???, ???CH2???CH2???CH2???, ???CH(CH3)???CH(CH3)??? and ???CH2???CH(alkyl) wherein said alkyl has from 1 to about 10 carbon atoms; and Ar is a member selected from the group consisting of phenyl, substituted phenyl, thienyl, halothienyl, naphthyl and fluorenyl, wherein ???substituted phenyl??? has the meaning of a phenyl radical having thereon from 1 to 3 substituents selected independent