The topological analysis of the electron localisation function (ELF) for a variety of RHC=NO iminoxy radicals shows that Z to E isomerisation results in a redistribution of electron density from the N and O lone electron pairs to the N-O and C=N bonds. Substitution of R by more electronegative group is associated with increase of (S) for V-1(O) boolean OR V-2(O) and decrease for V(N). The mean electron population of V(R,C) basin decreases with growing electronegativity of R. Dependence of A(iso)(H-1) hyperfine coupling on the R substituent may be explained as a consequence of an electron density delocalisation between the C-H and C-R bonds: V(C, H) double left right arrow V(C. R).