Noncovalent effects in the coordination and assembling of the[Fe(bpca)2][Er(NO3)3(H2O)4]NO3 system

摘要

In this work we perform a detailed analysis of the non-covalent effects that build the lattice of the [Fe(bpca)2][Er(NO3)3(H2O)4]NO3 compound, made of cationic d units [Fe(bpca)2]+,(where Hbpca is bis(2-pyridilcarbonyl)amine), neutral f complexes [Er(NO3)3(H2O)4], and the NO3- counter-ion. All these units are interlinked by hydrogen bonds, their assembling benefiting also from electrostatic effects. A particularly interesting sub-ensemble of the crystal is the linear chain formed by the lanthanide units. Going beyond the usual qualitative description of the supramolecular assembling, we performed electron structure calculations on appropriate models related to the experimental structures. The formation energies of d and f coordination bonds are estimated in semi-quantitative manner, being compared with the intermolecular ones, due to hydrogen bonding and dipolar interactions.