Electron-spin resonance studies of the titanium cation (Ti+,3d3,4F) in rare gas matrices at 4 K: A crystal field interpretation
Knight, L. B.; Keller, K. A.; Babb, R. M.; Morse, M. D. Electron-spin resonance studies of the titanium cation (Ti+,3d3,4F) in rare gas matrices at 4 K: A crystal field interpretation. J. Chem. Phys. 1996, 105, 5331-5331.
Electron-€spin resonance studies of laser-€ablated titanium metal isolated in neon and argon display an intense feature which exhibits a symmetric, narrow line and a large matrix-€dependent g shift. On the basis of a number of experiments, this is assigned to a matrix isolated 3d 3,4 F Ti+ ion in an octahedral matrix environment. Although the ground state of the gas-€phase Ti+ ion is 3d 24s 1,4 F, the assignment to the 3d 3,4 F state is supported by the small hyperfine structure which is observed. The neon magnetic parameters are: g=1.934(1) and A(47Ti)=64(1) MHz; for argon, g=1.972(1) and A=56(1) MHz. This unusual stabilization of an excited atomic state by a rare gas matrix is consistent with ab initio studies, and has been previously found for atomic nickel. A crystal-€field study of the expected behavior of a d 3,4 F ion isolated in a tetrahedral, octahedral, or cuboctahedral environment supports the assignment to an octahedral Ti+(Rg)6 species, and using the atomic spin-orbit parameter, Î¶ permits accurate values of Dq to be derived from the measured g values. Finally, it is also noted that for small values of Dq/(Dq+Î¶), or for a d 3,4 F ion in a tetrahedral environment, an as yet unobserved, unequal Zeeman splitting of the fourfold degeneracy occurs, causing a departure of the Zeeman energies from the standard formula of E Zeeman=Î² eH 0 gM, with M=-±3/2, -±1/2. For these situations it becomes necessary to define two values of g, corresponding to the more strongly (g 3/2) and less strongly (g 1/2) affected Zeeman levels, respectively.
Journal of Chemical Physics