Mass-analyzed threshold ionization and structural isomers of M3O4 (M = Sc, Y, and La)

Abstract

M(3)O(4) (M = Sc, Y, and La) were produced in a pulsed laser-vaporization molecular beam source and studied by mass-analyzed threshold ionization (MATI) spectroscopy and electronic structure calculations. Adiabatic ionization energies (AIEs) of the neutral clusters and vibrational frequencies of the cations were measured accurately for the first time from the MATI spectra. Five possible structural isomers of M(3)O(4) were considered in the calculations and spectral analysis. A cage-like structure in C(3v) point group was identified as the most stable one. The structure is formed by fusing three M(2)O(2) fragments together, each sharing two O-M bonds with others. The ground electronic state of the neutral clusters is (2)A(1) with the unpaired electron being largely a metal-based s character. Ionization of the (2)A(1) state yields a (1)A(1) ion state in a similar geometry to the neutral cluster. The AIEs of the clusters are 4.4556 (6), 4.0586(6), and 3.4750(6) eV for M = Sc, Y, and La, respectively. The observed vibrational modes of the cations include metal-oxygen stretching, metal triangle breathing, and oxygen-metal-oxygen rocking in the frequency range of 200-800 cm(-1).

Structural evolution, sequential oxidation and chemical bonding in tri-yttrium oxide clusters: Y3Ox− and Y3Ox (x = 0–6)

“…Other isomers are no less than 0.12 eV higher in energy as given in supplementary material (Table SI). The ground state of Y 3 O 4 is predicted to be 2 A 1 with C 3v symmetry ( Figure 5d) which is in agreement with the previous report 59 . It is similar to the ground state of Y 3 O 4 − cluster in term of atomic connectivity, except all the corresponding bond distances become a little shorter.…”

“…9e, the HOMO mainly consists of Y 5s character, which is contributed equally by each of the three Y atoms. Similar to the study by Wu,59 each Y atom possesses three valence electrons, and three Y atoms will lose a total of eight electrons to form the Y 3 O 4 À cluster. The orbital analysis indicates that the rest of the 5s electrons are distributed by the three yttrium atoms.…”

Chemistry and physics of dopants embedded in helium droplets

“…In this method, supersonic expansion of the molecules in a carrier gas, such as argon, can help to achieve extremely low temperatures down to 1 K. However, the flow downstream from the nozzle is highly inhomogeneous in density, velocity, and temperature. Therefore, the technique can only be employed for simple kinetic processes like vibrational relaxation and aggregation (Hawley & Smith, 1992; Krasnokutski & Yang, 2007; Krasnokutski et al, 2008; Wu et al, 2012).…”

Lanthanide Oxides: From Diatomics to High-Spin, Strongly Correlated Homo- and Heterometallic Clusters

“…Yang and co-workers measured the mass-analyzed threshold ionization (MATI) spectrum of La 2 O 2 , determining an IE of 4.5795 eV . The IE was lower for the larger La 3 O 4 cluster, 3.4750 eV . Ionization energies and structures of small (La 2 O 3 ) n ·LaO ( n = 1–3) clusters, which are reduced relative to the bulk stoichiometry by one O atom, were measured to be between 2.9 and 3.4 eV, with IEs dropping slightly with increasing n …”