An integrated instrument of DUV-IR photoionization mass spectrometry and spectroscopy for neutral clusters

Abstract

We have developed an integrated instrument combining deep ultraviolet laser ionization mass spectrometry (DUV-LIMS) and infrared multiphoton dissociation (IR-MPD) spectroscopy, abbreviated as DUV-IR. The 177.3 nm DUV laser (7 eV single-photon energy) has short pulse duration (15 ps) and appropriate pulse energy (∼20 µJ), which is found to be highly efficient for low-fragment photoionization of neutral metal clusters and molecules. A home-made cluster source is designed with an adjustable formation channel suitable for the generation of different cluster series. The well-aligned components of the reflection time-of-flight mass spectrometer, as well as the coaxial design of DUV laser and molecular beam, bring forth high sensitivity and high resolution of the DUV-LIMS. Taking these advantages, well-resolved neutral Vn (n = 1–43) and (Benzene)n (n = 1–25) clusters have been generated free of fragmentation. In addition to the generation and detection of neutral clusters, a fast-flow reaction tube is also designed downstream of the cluster source allowing to study their reactivity. In particular, a broad-range tunable IR laser (1.3–16 µm) is coupled with the DUV laser to attain IR-MPD spectroscopic analysis. This integrated system offers a general protocol to prepare various clusters to study their gas-phase reactivity and to determine their structures.

Superatomic Signature and Reactivity of Silver Clusters with Oxygen: Double Magic Ag 17 – with Geometric and Electronic Shell Closure

“…The experiments were conducted on a customized reflection time-of-flight mass spectrometer (Re-TOFMS) in combination with a laser evaporation (LaVa) source coupled with a fast-flow tube reactor. 30,31 A pulsed laser (532 nm, Nd 3+ :YAG, 15-20 mJ•pulse −1 , and 10 Hz) was used to generate the Ag n -(n = 10-34) clusters. The cluster ions generated in the gas channel were expanded and grown through a nozzle with an internal diameter of 1.5 mm, and then interacted with the reactant gas (O 2 seeded in He) in a compact fast-flow reactor (length ∼60 mm) with an instantaneous gas pressure at ∼55 Pa, that is, multiple collisions up to a few hundreds.…”

Tetrahedral Pt10– Cluster with Unique Beta Aromaticity and Superatomic Feature in Mimicking Methane

“…This study is based on a homemade reflection time-of-flight mass spectrometer (Re-TOFMS) combined with the newly developed pulsed laser vaporization cluster source (LaVa) ,− and a customized compact flow tube reactor. − A pulsed 532 nm Nd:YAG laser (10 Hz) with an energy of 15–35 mJ per pulse was used to generate the pure platinum clusters with good mass resolution via a cluster formation nozzle of 35 mm length (Φ = 1.35 mm) by ablation of a platinum disk (Φ = 16 mm, 99.99% purity) in the presence of a He carrier gas (1.0 MPa, 99.999% purity) which is controlled by a pulsed general valve (Parker, Serial 9). To obtain the continuous and stable Pt clusters, the Pt disk is set for a translational and rotational motion controlled by an eccentric gear set.…”

Plasma-Assisted Chain Reactions of Rh3+ Clusters with Dinitrogen: N≡N Bond Dissociation

“…This study is based on a customized reflection time-of-flight mass spectrometer (Re-TOFMS) 65 with a homemade laser vaporization (LaVa) source. A pulsed 532 nm Nd:YAG laser (10 Hz) is employed for the ablation of rhodium disk (Φ = 16 mm, 99.95%) in the presence of 5% N 2 seeded in a He carrier gas (99.999%, 10 atm) which is controlled by a pulsed general valve (Parker, Serial 9).…”