S1 Electronic Supplementary Information (ESI) for the manuscript: Nucleophilicity and electrophilicity of the C(sp 3 )H bond: methane and ethane binary complexes with iodine Alberto Baggioli, Stefano V. Meille, Antonino Famulari Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Politecnico di Milano, via Mancinelli 7, I-20131 Milano, Italia. Content: Results of a Natural Bond Orbital (NBO) analysis carried out on each of the complexes discussed. For each complex, Cartesian coordinates of the equilibrium geometry and atom labelling is also listed. E (2) refers to the second order perturbation energy, reported in kcal mol ‒1 , associated with electron density delocalization from a high occupancy natural bond orbital from a low occupancy one; ΔND and ΔNA refer to the occupancy change of the donor and acceptor orbitals respectively, relative to the occupancy of the same orbital in the isolated molecule, reported in atomic units. Symmetry-related multiplicity is explicitly marked (e.g. ×2 , ×3 ). complex M1 S2 complex M2 S3 complex M3 S4 complex E1 S5 complex E2 S6 complex E3 S7 complex E4 S8 Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics. This journal is © the Owner Societies 2017