The 2,2,2-crypt salts of the TI4Se84- and [TI2Se42-](infinity)(1) anions have been obtained by extraction of the ternary alloy NaTI0.5Se in ethylenediamine (en) in the presence of 2,2,2-crypt and 18-crown-6 followed by vapor-phase diffusion of THF into the en extract. The [2,2,2-crypt-Na](4)[TI4Se8](.)en crystallizes in the monoclinic space group P2(1)/n, with Z = 2 and a = 14.768(3) angstrom, b = 16.635(3) angstrom, c = 21.254(4) angstrom, beta = 94.17(3)degrees at -123 degrees C, and the [2,2,2-crypt- Na](2)[TI2Se4](infinity)(1.)en crystallizes in the monoclinic space group P2(1)/c, with Z = 4 and a = 14.246(2) angstrom, b = 14.360(3) angstrom, c = 26.673(8) angstrom, = 99.87(3)degrees at -123 degrees C. The TIIII anions, TI2Se66- and TI3Se75-, and the mixed oxidation state TII/TIIII anion, TI3Se65-, have been obtained by extraction of NaTI0.5Se and NaTISe in en, in the presence of 2,2,2-crypt and/or in liquid NH3, and have been characterized in solution by low-temperature Se-77, (TI)-T-203, and (TI)-T-205 NMR spectroscopy. The (1)J((TI)-T-203,205-Se-77) and (2)J((TITI)-T-203,205-T-213,205) couplings of the three anions have been used to arrive at their solution structures by detailed analyses and simulations of all spin multiplets that comprise the (TI)-T-205,203 NMR subspectra arising from natural abundance (TI)-T-205,203 and Se-77 isotopomer distributions. The structure of TI2Se66- is based on a TI2Se2 ring in which each thallium is bonded to two exo-selenium atoms so that these thalliums are four-coordinate and possess a formal oxidation state of +3. The TI4Se84- anion is formally derived from the TI2Se66- anion by coordination of each pair of terminal Se atoms to the TIIII atom of a TISe+ cation. The structure of the [TI2Se42-](infinity)(1) anion is comprised of edge-sharing distorted TISe4 tetrahedra that form infinite, one-dimensional [TI2Se42-](infinity)(1) chains. The structures of TI3Se65- and TI3Se75-are derived from TI4Se4-cubes in which one thallium atom has been removed and two and three exo-selenium atoms are bonded to thallium atoms, respectively, so that each is four-coordinate and possesses a formal oxidation state of +3 with the remaining three-coordinate thallium atom in the +1 oxidation state. Quantum mechanical calculations at the MP2 level of theory show that the TI2Se66-, TI3Se65-, TI3Se75-, and TI4Se84- anions exhibit true minima and display geometries that are in agreement with their experimental structures. Natural bond orbital and electron localization function analyses were utilized in describing the bonding in the present and previously published TI/Se anions, and showed that the TI2Se66-, TI3Se65-, TI3Se75-, and TI4Se84- anions are electron-precise rings and cages.