The mathematical properties of isomers numbers of substituted -based compounds presented in this paper includes : -(1) the formulation of 4-dimensional permutomers count vectors
and 5-dimensional itemized isomers count vectors IICV= which satisfy the dot product PCV = . (2)- The expansion of this equation to obtain the denumerants of
type mapping permutomers numbers as sum of symmetry itemized isomers numbers scaled by the markaracters
of . (3)-The collection of 4 and 5 entries and generating respectively, permutomers count matrices and itemized isomers count matrices that construct two associated vector spaces
of isomers numbers for such series of molecules.