Trends in the Spin States and Mean Static Dipole Polarizability of the Group VIIIA Metallocenes

Abstract

By using density functional theory, spin states, geometries, and mean static dipole polarizabilities of group VIIIA metallocenes M(C5H5)2 (M = Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, and Pt) are examined. For all metallocenes studied, comparison of the polarizability of the accessible spin states reveals that the lowest polarizability was found for the spin ground state. Therefore, our findings indicate that the minimum polarizability principle might be useful in determining the ground state multiplicity for transition metal metallocenes. The metallocenes from the group 8 and group 9 possess the same multiplicity, singlet and doublet, respectively. Additionally, one observes that the polarizability increases monotonically with the atomic number of the central metal atom for metallocenes from the same column. The B3LYP/ADZP is one of the most reliable procedure tested so far to predict the static dipole polarizability of the complexes studied here, with mean absolute deviation from the experimental data smaller than 1.8 au.

Molecules under external electric field: On the changes in the electronic structure and validity limits of the theoretical predictions

“…To obtain accurate results of the electrical properties, the ab initio level of theory must to be as high as possible and the basis set must be sufficiently flexible to describe the distortion of the external orbitals when the electric field is applied . However, the computational cost can be a prohibitive barrier and should also be considered.…”

“…Therefore, a deeper understanding on the electric response properties of molecular systems becomes highly desirable, not only from a basic science point of view, but especially also from a technological development perspective. In this scenario, one can highlight numerous of theoretical papers devoted to assess electric field induced changes on molecular properties, such as structural,vibrational, electronic state, optical, magnetic and electric …”

Size and shape effects on the stability, electronic structure, and Raman spectroscopy of (SrO)n nanoclusters

“…The same analyses can be done for BE. Although the MPP fails in some cases [16, 18], the connection among the polarizability, SOE, and BE presented above for the majority of the systems is indicative of the good accuracy of the polarizability calculated here.…”

“…The static dipole polarizability represents one of the most important observables for understanding both electric and optical properties of molecular systems [16,18,45,46,50,51]. It is defined as the negative of the second derivative of the energy respective to the external electrical field.…”

“…Thus, the analysis of the various isomers, which can be very close in energy, represent an important issue and properties such as binding energy, the energy of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), second‐order energy, ionization potential, electron affinity, and isotropic polarizability can help to shed light on the stability of the low‐lying energy isomers [12–15]. Furthermore, it is well known that metal clusters can present relatively small energy splitting between the accessible spin states, turning the search for the global minimum even more challenging [16–18]. It is worth noting that different levels of theory can lead to contrasting ground spin‐state structures and, consequently, discrepant electronic properties [2, 11].…”