Thus, these two are tautomers. Eclipsed and staggered ethane are two conformations of ethane. (+) 2-butanol and (-)2-butanol are enantiomers as these are non-superimposable mirror images.
CH3NHC3H7
(methyl−n−propylamine)
and
C2H5NHC2H5
(diethylamine)
Due to difference in the nature of alkyl groups attached to the same functional group, these are called metamers.