Photoelectron spectroscopy of AlnS1− clusters (n=1−9)

Abstract

Photoelectron spectra of AlnS−1 (1≤n≤9) cluster anions were measured at the photon energies of 3.49 and 4.66 eV, using a magnetic bottle electron spectrometer having ∼60 meV resolution. AlS− has an electron affinity of as large as 2.6 eV, attributed to large stability by six bonding electrons. A new electronic state, A′ 2Π, was found 0.4 eV above the AlS ground state, which is in agreement with theoretical calculations. AlnS−1 cluster anions are produced efficiently up to n=5, but the production of larger cluster sizes is found difficult. The mass distribution of AlnS−1 cluster anions and electron binding energy can be explained by a geometric structure obtained by theoretical calculation.

Communications: Investigation of the superatomic character of Al13 via its interaction with sulfur atoms

“…ter anions estimated from the photoelectron spectra are listed in Table S1. 11 Note the photoelectron spectra of small aluminum-sulfur clusters, such as Al n S − ͑n =1-9͒ and Al n S m − ͑n Յ 5, m Յ 3͒, have also been reported by Nakajima et al, 12,13 our spectra are consistent with their work. Figure 3 shows the variation in VDEs and ADEs with the number of aluminum atoms ͑n͒ in Al n S − and Al n S 2 − clusters.…”

“…Thus, isomer 1A might be the most possible isomer detected in our experiments. The structure of Al 12 unit in isomer 1A is very different from the structures of bare Al 12 or Al 12 − . [15][16][17] For the Al 12 S 2 − cluster, the sulfur atoms also prefer to occupy the exterior sites.…”

“…Since the electron affinity of Al 13 is much higher than that of sulfur atom ͑2.08 eV͒, we would expect most of the negative charge in Al 13 S − cluster to be localized on Al 13 . We investigated the charge distributions of Al 12 S − and Al 13 S − , and found that the excess electron is mainly localized on the Al n core, with about 0.65e on Al 12 and approximately from 0.60e to 0.65e on Al 13 . Al 13 is not very different from Al 12 in this case.…”

Photoelectron spectroscopy of transition metal-sulfur cluster anions

“…Since photodetachment is a process of transition from the ground state of anions into the ground state or electronic excited states of the corresponding neutrals, therefore, the electronic properties of the neutral clusters are readily observed from the photoelectron spectra. While the most works on anion PES have been reported for pure elemental and molecular clusters [7], and for solvated anions of the type of A − (X) n (X is solvent molecules) [10,11], there is an increasingly recent interest on the study of binary cluster anions of the type of A n B − m [12,13], in which A and B can be a metal or nonmetal element or both.…”

“…Since photodetachment is a process of transition from the ground state of anions into the ground state or electronic excited states of the corresponding neutrals, therefore, the electronic properties of the neutral clusters are readily observed from the photoelectron spectra. While the most works on anion PES have been reported for pure elemental and molecular clusters [7], and for solvated anions of the type of A − (X) n (X is solvent molecules) [10,11], there is an increasingly recent interest on the study of binary cluster anions of the type of A n B − m [12,13], in which A and B can be a metal or nonmetal element or both.Among the binary clusters, the study of transition-metal sulfides has attracted broad attention over the past decades because of their solids exhibiting a variety of electronic and structural characteristics [14]. The layered structures of some metal sulfides lead to unique properties of conductivity [15][16][17] and lubrication (MoS 2 ) [18].…”