Infrared spectroscopy and density functional calculations on titanium-dinitrogen complexes

Abstract

Titanium-nitrogen complexes were generated by laser ablated titanium (Ti) atoms and N-2 gas molecules in this study. These complexes were isolated on the pre-deposited solid Ar matrix on the pre-cooled KBr window (T similar to 5.4 K), allowing infrared spectra to be measured. Laser ablation experiments with N-15(2) isotope provided distinct isotopic shifts in the infrared spectra that strongly implicated the formation of titanium-nitrogen complexes, Ti(NN)(x). Density functional theory (DFT) calculations were employed to investigate the molecular structures, electronic ground state, relative energies, and IR frequencies of the anticipated Ti(NN)(x) complexes. Based on laser ablation experiments and DFT calculations, we were able to assign multiple Ti(NN)(x) (x = 1-6) species. Particularly, Ti(NN)(5) and Ti(NN)(6), which have high nitrogen content, may serve as good precursors in preparing polynitrogens. (C) 2018 Elsevier B.V. All rights reserved.