Compounds with (NHC)→E coordination bond are being generated and their chemistry is being explored over the past 15 years (NHC= N-heterocyclic carbenes, E = main group elements). Many examples of species with N-heterocyclic olefins (NHOs) are known, which exhibit umpolung chemistry. Increasing number of chemical species, which carry NHC as a functional unit, are being reported. There is a need to understand their electronic structure. Alkylated imidazole oximes (cationic, found useful in medicinal chemistry) ((NHC)-C(H)=N-OH(+)) carry NHC unit as a functional group. Similarly, the corresponding nitroso-N-heterocyclic olefins ((NHC)=C(R)-N=O) also carry NHC as a functional unit. It is important to establish the interaction between the NHC unit and the rest part of the molecule in these species. Density functional (DFT) study has been carried out to explore the electronic structure details of a few oximes and nitroso NHOs. The results indicate that a structure with NHC→C coordination interaction can be considered as one of the resonance structures of these species.