The new compound trifluoroacetylsulfenyl trifluoroacetate, CF3C(O)SOC(O)CF3, which possesses two identical carbonyl substituents attached to the S-O bond, has been synthesized. The IR and UV spectra of the gas phase as well as the C-13 NMR spectrum of the solution in CDCl3 were recorded and assigned. Quantum chemical calculations were performed with the ab initio methods HF and MP2 and the density functional approach B3LYP. The 6-31G* basis set was chosen in all calculations. The molecule possesses a skew structure, and according to all computational methods, the syn-syn structure (C=O bonds of both C(O)CF3 groups synperiplanar to S-O bond) represents the most stable conformer. In agreement with the quantum chemical calculations, the presence of small amounts (less than or equal to5%) of a second conformer (anti-syn) cannot be excluded on the basis of the IR spectrum. The calculated values for the torsional angle around the S-O bond (delta(C-S-O-C)) of the syn-syn form are smaller than 80degrees (72-78degrees). Comparison with theoretical results for the corresponding disulfide CF3C(O)SSC(O)CF3 and peroxide CF3C(O)OOC(O)CF3 indicates that the structural properties of sulfenyl compounds are more similar to those of disulfides than to those of peroxides.