Anion photoelectron spectroscopy and chemical bonding of ThO2− and ThO3−

Abstract

We conducted a study of electronic structures and chemical bonding of gaseous ThO and ThO using velocity-map imaging and ab initio calculations. The electron affinity of neutral ThO molecule is reported for the first time with the value of 1.21(5) eV. We obtained a vibrationally resolved photoelectron spectroscopy of ThO and observed the symmetric stretching frequency of 824(40) cm for neutral molecules. One hot band transition is observed in the spectrum of ThO, which allows the measurement of symmetric stretching mode for ThO. The ground state of ThO is A with C symmetry: the detachment of an electron from the singly occupied molecular orbital (SOMO) results in the ground state of ThO. Kohn-Sham molecular orbital analyses reveal an σ and two weak π bonds for Th-O multiple bonds in ThO. Global minimum search methodology combined with quantum chemical calculations are used to find the minima of ThO and ThO, and the adiabatic detachment energy of ThO is calculated to be 3.26 eV at the coupled cluster with singles and doubles plus perturbative triples level. Our theoretical calculations suggest that the ground state of ThO is A' with a symmetry of C, while the most stable ThO is A with C symmetry; thus, the transition from ThO to ThO undergoes a significant geometry reorganization. Molecular orbital analyses suggest that the SOMO of ThO is mainly participated by O 2p and O to Th back donation was found in HOMO-2 molecular orbital. This investigation will shed some light on the understanding of covalent bonding in Th-contained molecules.

Reactions of Thorium Oxide Clusters with Water: The Effects of Oxygen Content

“…The molecular structure of H 2 O has been well-known, and the ground-state structures of ThO n (n = 1-3) clusters have also been reported in the earlier work. [21][22][23][33][34] Our groundstate geometries are all in agreement with them. The most stable ThO is the closed-shell (C ∞v 1 Σ + ) structure (Figure 1b).…”

“…It can be regarded as attaching an O 2 unit to the ThO moiety. [23] Its triplet analogue (C s 3 A") is 40.1 kcal/mol higher in energy (Figure 1g). The OÀ O bond length in ThO 3 (C s 1 A') is (1.531 Å calculated at the same level).…”

“…Many experimental and theoretical researchers have devoted effort to studying the structures, bonding and reactivity of thorium oxide clusters. [7,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Among them, several studies have revealed the stable structures of thorium oxide clusters. [21][22][23][31][32][33]35] Anionic photoelectron spectra combined with theoretical calculations have been carried out to explore the electronic structures and chemical bonding of the gasphase ThO n À /0 (n = 1-3) clusters.…”

“…[7,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Among them, several studies have revealed the stable structures of thorium oxide clusters. [21][22][23][31][32][33]35] Anionic photoelectron spectra combined with theoretical calculations have been carried out to explore the electronic structures and chemical bonding of the gasphase ThO n À /0 (n = 1-3) clusters. [22][23] They found the linear ThO and its anion were the 1 Σ g + and 2 ~electronic state, respectively.…”

“…[21][22][23][31][32][33]35] Anionic photoelectron spectra combined with theoretical calculations have been carried out to explore the electronic structures and chemical bonding of the gasphase ThO n À /0 (n = 1-3) clusters. [22][23] They found the linear ThO and its anion were the 1 Σ g + and 2 ~electronic state, respectively. Both ThO 2 and its anion had the obtuse isosceles triangle structures with two terminal oxygen atoms.…”