Pentacoordinated pyramidal structures and bonding properties of WN10−/0: anion photoelectron spectroscopy and theoretical calculations

Abstract

Anion photoelectron spectroscopy and theoretical calculations were used to investigate the structural and bonding properties of WN₁₀^−/0. The electron affinity of WN₁₀ is measured to be 1.582 ± 0.030 eV. The frequency of the NN stretch in WN₁₀ is measured to be 2170 ± 80 cm⁻¹, which is red-shifted with respect to that of the dinitrogen molecule indicating that the NN bonds are weakened in WN₁₀. The theoretical adiabatic detachment energy (ADE) and vertical detachment energy (VDE) of WN₁₀⁻ obtained by calculations at the CCSD(T)/CBS level agree well with experimental results. The structures of WN₁₀^−/0 are C_4v symmetric pentacoordinated pyramidal structures with five end-on dinitrogen ligands. Our experiments show that the peak of WN₁₀⁻ is dominant in the mass spectrum of anionic WN_n, whereas the mass peak of WN₁₂⁺ is dominant in the mass spectrum of cationic WN_n, implying that the stabilities of WN_n clusters are strongly related to their charge states.