A Theoretical Study of Binary and Ternary Hydride-Bonded Complexes N(Beh2)...X with N = 1 or 2 and X = K+ or Ca+2

A theoretical study of hydride bonds formed between beryllium hydride and alkaline earth metal cations is presented. B3LYP/6-311++G(d,p) calculations were used for determining the optimized geometries of the BeH2...K+, BeH2...Ca+2, BeH2...K+...BeH2, and BeH2...Ca+2...BeH2 hydride-bonded complexes, where among them the first are binaries, whereas the last ones are ternaries with the calcium (Ca+2) and potassium (K+) ions mediating the interactions with the beryllium hydride (BeH2). A detailed structural analysis were performed, by which the yielded profiles are in good agreement with results of the infrared vibrational spectrum, mainly in regards to the existence of red-shifted modes followed by enlarged absorption intensity ratios of the B-H bonds of the binary complexes. The capability of either donating or accepting of protons among BeH2, K+, and Ca+2, is currently treated in conformity with Lewis’s acid/base theory, but is also interpreted through the application of the Quantum Theory of Atoms in Molecules (QTAIM), whose formalism consents in the molecular modeling of concentrations and depletions of charge density ruled by the Laplacian shapes, charge transference fluxes, as well as by the local virial theorem of the electronic density with quantification of the kinetic and potential energies along the bonds and interactions.