r 6 is selected from the group consisting of r 1 har hetcy and or 11 wherein r 1 is as originally defined r 11 is r 1 or har and r 12 is c 1 6 alkyl aryl or har said aryl and har being optionally substituted with 1 4 r 13 groups or r 11 and r 12 are taken in combination with the atom to which they are attached and represent a 5 6 membered ring optionally substituted with 1 2 r 13 groups within this aspect of the invention all other variables are as originally defined in another aspect of the invention a compound of formula i is disclosed wherein r 13 is selected from the group consisting of halo c 1 4 alkyl c 3 7 cycloalkyl aryl har hetcy and or 15 wherein r 15 is h said alkyl cycloalkyl aryl har and hetcy being optionally substituted with 14 substituents selected from r 18 and r 18 is halo c 1 4 alkyl aryl or co 2 c 1 4 alkyl within this aspect of the invention all other variables are as originally defined in yet another aspect of the invention that is of particular interest a compound of formula i is disclosed wherein r 1 is selected from the group consisting of h c 1 10 alkyl c 3 6 cycloalkyl and phenyl said alkyl and phenyl being optionally substituted with 1 3 substituents selected from r 13 r 2 is h m is 0 and n is 2 or 3 or m is 1 and n is 1 or 2 such that the sum of.