The primary reaction products of laser-ablated uranium atoms with dihydrogen (UH, UH2, UH3, UH4, U2H2, and U2H4) have been isolated for the first time in solid argon and identified by the effects of isotopic substitution on their infrared spectra. Calculations, using DFT methods, have been performed to provide theoretical support for the spectral assignments. The molecules U(μ-H2)U and U2H4 represent the first examples of an actinide-actinide bond.

Group 6 metal atoms, generated by laser ablation, react with CO2 to give the insertion products OMCO and O2M(CO)2 (M = Cr, Mo, or W) which have been isolated in argon matrices and identified by the effects of isotopic substitution on their infrared spectra. These assignments have been supported by DFT calculations, and the theoretical and experimental spectra are in excellent agreement. Other products include the molecules O2MCO, MO, and MCO and the CO2 complex Cr (η1-OCO) which, upon irradiation with UV-light, will photoisomerize to give OCrCO, an interesting example of photoactivation of CO2.

The primary reaction products of laser-ablated thorium atoms with dihydrogen, ThH, ThH2, ThH3, and ThH4 have been isolated for the first time in an argon matrix and identified by the effects of isotopic substitution on their infrared spectra. DFT calculations provide firm theoretical support for the spectral assignments.

The reactions of laser-ablated thorium and uranium metals in condensing pure dinitrogen streams as well as argon/dinitrogen mixtures have provided spectroscopic evidence for the presence of several previously uncharacterized actinide metal nitrides and dinitrogen complexes. Infrared spectra of the matrix isolated product species indicate that thorium and uranium atoms have a significant bond weakening effect on dinitrogen upon initial complexation and in some cases complete dinitrogen bond cleavage is observed. In the reactions of laser-ablated thorium and uranium atoms with pure dinitrogen, the primary products are the metal mononitride (M-N), the metal dinitride (N–M–N), and in the uranium reactions, two dinuclear products U(μ-N)2U and NU(μ-N)2U. In the reactions of thorium with dinitrogen in argon, the primary products are N–Th–N, Th(μ-N)2Th, and the dinitrogen complexes Th-η1-N2 and Th-η1:η1-(N2)2. The complete ground-state electronic structure and vibrational spectrum of each product molecule has been modeled using quasirelativistic density functional calculations in order to lend support to the spectral assignments and to give insight into the electronic structure of these new species.

Laser-ablated molybdenum and tungsten atoms were reacted with dioxygen and 18O-substituted dioxygen. The products of these reactions were isolated in solid argon matrices at 10 K and studied by matrix infrared spectroscopy. Analysis of spectra enabled identification of reaction products, which included MoO2, (O2)MoO2, MoO3, WO, WO2, (O2)WO2, and WO3. Resolution of isotopic splitting due to natural isotopic abundance of the metal verified the presence of a single metal atom in these molecules and allowed for calculation of bond angles for the molybdenum and tungsten dioxide molecules and their dioxygen complexes.