Resonant two-photon ionization spectroscopy of jet-cooled Pt2

Abstract

The gas phase optical spectrum of jet-cooled Pt2 has been investigated over the range of 11 300 to 26 300 cm−1 using resonant two-photon ionization spectroscopy in combination with time-of-flight mass spectrometry. Numerous vibronic bands are observed. Analysis of the data gives the location of some 26 excited electronic states, which are characterized by the frequencies of their origin bands, vibrational frequencies, and anharmonicities. Variation of the second color in a two-color resonant two-photon ionization scheme has determined the ionization threshold of Pt2 to be 8.68±0.02 eV. The observation of the onset of predissociation, characterized by a sharp drop in excited state lifetime, places the dissociation energy of Pt2 at 3.14±0.02 eV. In combination with the Pt atomic ionization potential of 8.8±0.2 eV, these results give the bond strength of Pt+2 as D0(Pt−Pt+)=3.26±0.24 eV. The strength of the chemical bond in Pt2, as compared to Au2, demonstrates that there are significant 5d contributions to the chemical bonding in Pt2.

Investigation of the use of density functionals in second‐ and third‐row transition metal dimer calculations

“…The Pt 2 molecule also contains much more relativistic effect, including spin-orbit coupling. Experiments suggest two candidates for the dissociation energy: D e = 3.14 ± 0.02 eV, 50 and 3.71 ± 0.16 eV. 51 The ab initio CASPT2 method favors 3.71 ± 0.…”

Structural and electronic properties of the Ptn–PAH complex (n = 1, 2) from density functional calculations

“…The results of the relative energy, E rel (the energy relative to the lowest spin-state), binding energy and bond length for different spin multiplicities of Pt atom and dimer are shown in Table 1. The spin multiplicities have a large effect on 95 . Adopting a valence bond approach, the bonding in transition-metal dimers can be described as a multiple bond formed between two atoms in a d n s state.…”

Cavity ringdown laser absorption spectroscopy and time-of-flight mass spectroscopy of jet cooled platinum silicides

“…A large number of other platinum containing diatomic molecules have recently been investigated experimentally, including PtS, 5 PtC, 6 PtN, 7 PtO, 8 and Pt 2 . 9 In this article, following our recent work on the coinage metal silicides ͑MSi, where MϭCu, Ag, Au͒, [10][11][12] we present the results of a study of jet-cooled platinum silicide clusters using cavity ringdown laser absorption spectroscopy ͑CRLAS͒ and time-of-flight mass spectroscopy ͑TOFMS͒, including the first spectroscopic characterization of the gas phase diatomic PtSi molecule.…”