The intramolecular E center dot center dot center dot N (E= Se, Te) interactions between the selenium (and tellurium) and the nitrogenatom in four series of o-substituted organochalcogen compounds have been analyzed using density functional theory. The nature and the strength of this interactions and their dependence on substituents and the rigidity are predicted using B3LYP/6-31 G(d)/LanL2DZ method. The strength of these E center dot center dot center dot N interactions are found to be dependent on the nature of E- X (X= CI, Br, I, SPh, CH2Ph; Ph: Phenyl) acceptor orbitals and follows the order I > Br > CI > SPh > CH2Ph. The Natural Bond Orbital (NBO) analysis using DFF methods points to nN ->sigma*(E-X) electron delocalization as the key contributing factor toward E center dot center dot center dot N nonbonding interactions. Both NBO and AIM methods suggest that the intramolecular interaction in these compounds is dominantly covalent in nature. Studies on the effect of solvent on the E center dot center dot center dot N interactions show that polar solvent stabilizes these interactions by shortening the E center dot center dot center dot N distances. (C) 2013 Elsevier B.V. All rights reserved.