title: Contrasting preferences of N and P substituted heteroaromatics towards metal binding: probing the regioselectivity of Li+ and Mg2+ binding to (CH)(6-m-n)N(m)P(n).
abstract: High level ab initio and hybrid DFT methods have been employed to investigate the interactions of metal ions (Li(+) and Mg(2+)) with N and P substituted six membered heteroaromatics (CH)(6-m-n)N(m)P(n). The binding energy (BE) of metal ions with the N and P substituted heteroaromatics has been computed at the CCSD(T)/cc-pVTZ//MP2/cc-pVTZ level with counterpoise correction. In the present study we systematically examined the preferential modes of binding of metal ions to the heteroaromatics. N-Substituted heteroaromatics show a strong preference for cation-σ mode of binding whereas the P-substituted heteroaromatics prefer cation-π mode of binding with the metal ions. Energy decomposition analysis (EDA) using the DFT-SAPT scheme has been carried out to analyse the contribution of various energy components to the BE. The results illustrate that for the cation-π complexes, the contribution of the induction term is more whereas in the case of cation-σ there is a competition between induction and electrostatic terms in the interaction energy.
authors.affiliation: Molecular Modeling group, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India.
authors.forename: Bhaskar
authors.initials: B
authors.lastname: Sharma
authors.forename: Deivasigamani
authors.initials: D
authors.lastname: Umadevi
authors.forename: G
authors.initials: G
authors.lastname: Narahari Sastry
mesh_terms: D001665:Binding Sites; D002412:Cations / Q000737:chemistry*; D004583:Electrons; D008094:Lithium / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D002412:Cations; D011084:Polycyclic Aromatic Hydrocarbons; D008094:Lithium; D008274:Magnesium