Ab initio study of the static dipole polarizability of neutral and charged naphthalene

Abstract

SUMMARYWe present an ab initio SCF-MO study of the static dipole polarizability of some neutral and charged species of naphthalene (C10H8) q , (q = −2, −1, 0, +1, +2). The charged species involve additions and removals of electrons to and from the HOMO and LUMO π-electron orbitals. The polarizability calculations were performed using the Coupled Perturbed Hartree-Fock method, and in addition, we used direct analytical differentiation of the energy expression. We used a series of split valence basis sets augmented with sp diffuse and polarized functions STO/6-31+G(md,np, (m = n = 1, 2, 3), and all geometries were fully optimized. Molecular structure optimizations were generally started from the geometry predicted for neutral naphthalene with D2h symmetry at the HF/6-31G** level of theory.The Hartree-Fock results indicate that the anisotropies of the components of the dipole polarizability tensor of neutral naphthalene (q = 0) are in agreement with our own previous theoretical calculations and with the experimental values corresponding to laser Stark spectroscopy in a naphthalene molecular beam. This agreement with experimental results can be further improved with extension of the number of polarized functions in the basis set.We also analyse the effect of the negative and positive charges on the naphthalene molecule on the polarizability tensor components. The variation of molecular geometry also plays a part in these changes.

Analytic calculations of nonlinear mixed electric and magnetic frequency-dependent molecular properties using London atomic orbitals: Buckingham birefringence

“…Since we are resorting to an approach where electron correlation effects are neglected, we refrain from going into a detailed discussion of the comparison of the first-order (the molecular dipole and quadrupole moments) and of the linear response properties-a(o), A(o) and G 0 (o)-with other computational results or experiment. Ab initio studies of the electric dipole polarizability 74 and quadrupole moment 75 of naphthalene can be found in the literature. The Buckingham birefringence of furan was the subject of ref.…”

Static and Dynamic Polarizabilities of Conjugated Molecules and Their Cations

“…Static isotropic polarizabilities of molecular ions have been studied theoretically, although not as extensively as for neutral molecules. For example, the static polarizabilities of the molecular ions of naphthalene have been calculated , for charge states of the ion ranging from +2 to −2 and varies from 15 to 25 Å 3 . However, it is dynamic polarizabilities (of both neutral molecules and their cations) that are primarily relevant in the investigations of laser−molecule interaction.…”

A microspectroscopic insight into the resistivity switching of individual Ag–TCNQ nanocrystals

“…However, an absolute quantification of affected molecules based on Raman spectroscopy is problematic even with the clear shift observed, due to dissimilar polarizability tensors of neutral and negatively charged molecules. 25…”