Abstract: The invention provides a compound and tautomeric forms thereof having the formula: wherein Rf1 is selected from the group consisting of hydrogen, a straight chain, branched secondary or branched tertiary C1-C20 perfluoroalkyl group optionally containing ether or thioether linkages and C1-C10 perfluoroalicyclic group optionally containing ether or thioether groups; Rf2 is a straight or branched C1-C20 perfluoroalkylene group optionally substituted with ether and thiother linkages; and X is selected from the group consisting of fluorine and The invention also provides perfluoroelastomeric compositions cured with the perfluoroimidoylamidines of the invention as well as combinations of perfluoroimidoylamidines and other curing agents.