Distinct chemical reaction networks (CRNs) may lead to the same dynamics; this fact has been termed the fundamental dogma of chemical kinetics. We use Lie algebra of derivations to construct a tangent space along trajectories of vector fields, induced by CRNs, such that their dynamical structure is preserved via the construction of a diffeomorphic map Phi. Thus, given two CRNs, it is possible to express the states (i.e. chemical species concentration) of one CRN as function of the other and vice versa, via the composition of their diffeomorphic maps. We call these map compositions the dynamical equivalence. (C) 2012 Elsevier Ltd. All rights reserved.