atoms in the moiety i e the prefix c i j defines the number of carbon atoms present from the integer u201c i u201d to the integer u201c j u201d inclusive thus c 1 4 alkyl refers to alkyl of one to four carbon atoms inclusive or methyl ethyl propyl butyl and isomeric forms thereof as stated above aryl het c 1 4 alkyl c 1 12 alkyl c 2 12 alkenyl c 2 12 alkynyl c 3 8 cycloalkyl c 3 8 cycloalkenyl q and phenyl may be substituted as appropriate aryl is preferably substituted with c 1 4 alkyl c 1 4 alkoxy phenyl o phenyl het o het halo such as fluoro chloro bromo oh u2014 no 2 u2014 cn u2014 cf 3 u2014 n r 3 2 such as u2014 n c 1 4 alkyl 2 u2014 sr 3 u2014 so 2 c 1 4 alkoxy u2014 ch 2 h het u2014 c u2550 o r 3 or u2014 nhc u2550 o r 3 het is preferably substituted with c 1 4 alkyl pheny phenoxy or halo c 1 12 alkyl is preferably substituted with one to three halo cn u2014 no 2 or u2014 cf 3 u2014 n r 3 2 such as u2014 n c 1 4 alkyl 2 u2014 sr 3.