Abstract
Ab initio calculations were employed to investigate M(+)-RG2 species, where M(+) = Ca, Sr, Ba, and Ra and RG = He-Rn. Geometries have been optimized, and cuts through the potential energy surfaces containing each global minimum have been calculated at the MP2 level of theory, employing triple-ζ quality basis sets. The interaction energies for these complexes were calculated employing the RCCSD(T) level of theory with quadruple-ζ quality basis sets. Trends in binding energies, De, equilibrium bond lengths, Re, and bond angles are discussed and rationalized by analyzing the electronic density. Mulliken, natural population, and atoms-in-molecules (AIM) population analyses are presented. It is found that some of these complexes involving the heavier group 2 metals are bent whereas others are linear, deviating from observations for the corresponding Be and Mg metal-containing complexes, which have all previously been found to be bent. The results are discussed in terms of orbital hybridization and the different types of interaction present in these species.
Highlights
Weak electrostatic interactions have been studied abundantly in the past two decades, both experimentally and theoretically
The explanation for the difference in the equilibrium geometry for the Group 2 containing species was the occurrence of sp hybridization of the outermost occupied s orbital on the metal centre
Quantum chemical calculations reported in the same work confirmed that a bent equilibrium structure was preferred at the MP2/aug-cc-pVQZ level of theory; because of basis set superposition error, and the very small energy differences, this was not considered a conclusive result by the authors
Summary
Weak electrostatic interactions have been studied abundantly in the past two decades, both experimentally and theoretically. The explanation for the difference in the equilibrium geometry for the Group 2 containing species was the occurrence of sp hybridization of the outermost occupied s orbital on the metal centre. In the present work we extend our previous study to the M+-RG2 complexes containing a heavier Group 2 metal cation (M = Ca–Ra), to examine if these bent geometries persist. Quantum chemical calculations reported in the same work confirmed that a bent equilibrium structure was preferred at the MP2/aug-cc-pVQZ level of theory; because of basis set superposition error, and the very small energy differences, this was not considered a conclusive result by the authors.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
