The CCl3+ and CBr3+ cations have been synthesized by oxidation of a halide ligand of CCl4 and CBr4 at -78 degreesC in SO2CIF solvent by use of [XeOTeF5][Sb(OTeF5)(6)]. The CBr3+ cation reacts further with BrOTeF5 to give CBr(OTeF5)(2)(+), C(OTeF5)(3)(+), and Br-2. The [XeOTeF5][Sb(OTeF5)(6)] salt was also found to react with BrOTeF5 in SO2ClF solvent at -78 degreesC to give the Br(OTeF5)(2)(+) cation. The CCl3+, CBr3+, CBr-(OTeF5)(2)(+), C(OTeF5)(3)(+), and Br(OTeF5)(2)(+) cations and C(OTeF5)(4) have been characterized in SO2ClF solution by C-13 and/or F-19 NMR spectroscopy at -78 degreesC. The X-ray crystal structures of the CCl3+, CBr3+, and C(OTeF5)(3)(+) cations have been determined in [CCl3][Sb(OTeF5)(6)], [CBr3][Sb(OTeF5)(6)].SO2ClF, and [C(OTeF5)(3)][Sb(OTeF5)(6)].3SO(2)ClF at -173 degreesC. The CCl3+ and CBr3+ salts were stable at room temperature, whereas the CBrn(OTeF5)(3-n)(+) salts were stable at 0 degreesC for several hours. The cations were found to be trigonal planar about carbon, with the CCl3+ and CBr3+ cations showing no significant interactions between their carbon atoms and the fluorine atoms of the Sb(OTeF5)(6)(-) anions. In constrast, the C(OTeF5)(3)(+) cation interacts with an oxygen of each of two SO2ClF molecules by coordination along the three-fold axis of the cation. The solid-state Raman spectra of the Sb(OTeF5)(6)(-) salts of CCl3+ and CBr3+ have been obtained and assigned with the aid of electronic structure calculations. The CCl3+ cation displays a well-resolved Cl-35/Cl-37 isotopic pattern for the symmetric CCl3 stretch. The energy-minimized geometries, natural charges, and natural bond orders of the CCl3+, CBr3+, Cl-3(+), and C(OTeF5)(3)(+) cations and of the presently unknown CF3+ cation have been calculated using HF and MP2 methods have been compared with those of the isoelectronic BX3 molecules (X = F, Cl, Br, I, and OTeFs). The C-13 and B-11 chemical shifts for CX3+ (X = Cl, Br, I) and BX3 (X = F, Cl, Br, I) were calculated by the GIAO method, and their trends were assessed in terms of paramagnetic contributions and spin-orbit coupling.