DFT calculations of Ti-based molecules clustering with Ar for laser-based enrichment of stable isotopes

Within PRISMAP, the European medical radionuclides program, we are investigating the possible enrichment of titanium and calcium stable isotopes by means of Separation of Isotopes by Laser Assisted Retardation of Condensation (SILARC). Titanium or calcium-containing molecules are injected in a gas cell containing argon as a buffer gas and released via a nozzle creating a supersonic jet. The temperature drops to similar to 15 K, at which point argon atoms cluster around the molecules. If an isotopomer can be selectively excited by an infrared laser, the clusterization can be prevented and the molecule experiences a drag force through the jet, physically separating it from the clusters. As a first step in this development, Density Functional Theory (DFT) calculations have been performed on titanium-containing molecules, to determine the ground-state configuration of the molecules (geometry and spin state), their interaction with Ar, and to calculate the frequencies of their vibrational modes as a function of Ti isotope. Isotope-selective transitions were identified, mostly in the mid-infrared region. In this contribution, the results from those calculations for simple molecules (TiFx (x = 1-4)) and complex molecules (Ti[OEt]4, Ti[OPr(])4, C10H2TiF12O4) are reported.

Automated summary

Within the European medical radionuclides program PRISMAP, the possible enrichment of titanium and calcium stable isotopes through SILARC is investigated. In this process, titanium or calcium-containing molecules are injected into a gas cell with argon as a buffer gas and released via a nozzle to create a supersonic jet. By selectively exciting an isotopomer with an infrared laser, the molecule can be physically separated from the clusters formed by argon atoms. Density Functional Theory calculations have been performed on titanium-containing molecules to determine their ground-state configuration, interaction with argon, and calculate the frequencies of their vibrational modes.