The infrared spectrum of (\mathrm{CF}{2} \mathrm{O}{2}) has been studied in the (800-1600 \mathrm{~cm}^{-1}) region with a resolution of ca. (0.003 \mathrm{~cm}^{-1}). Rotational fine structure was resolved, and the supposed cyclic difluorodioxirane structure with (C_{2 v}) symmetry, (\kappa=-0.0632), was confirmed. The (\nu_{1}) and (v_{2}) bands, which reveal (a) type structure and are centered at 1466.591 and (917.905 \mathrm{~cm}^{-1}), respectively, and the (c)-type band (\nu_{8}) centered at (1062.102 \mathrm{~cm}^{-1}) have been analyzed employing Watson's (A)-reduced Hamiltonian in the (I^{\prime}) representation. For each of these bands. between 4100 and 5600 lines were fitted, with (\sigma=3.5-4 \times 10^{-4} \mathrm{~cm}^{-1}). No perturbations were found. Ground state constants of the novel (\mathrm{CF}{2} \mathrm{O}{2}) molecule were determined for the first time from a fit of ca. 7500 ground state combination differences formed from transitions belonging to (\nu_{1}, v_{2}), and (\nu_{8}), which were fitted with (\sigma=4 \times) (10^{-4} \mathrm{~cm}^{-1}). The rotational constants (A_{0}=0.26575541(28) \mathrm{cm}^{-1}, B_{0}=0.21095653(14) \mathrm{cm}^{-1}), and (C_{0}=0.16266791(15) \mathrm{cm}^{-1}) were determined. Assuming a (C-F) bond length of (131.5 \mathrm{pm}), the structural parameters (d(\mathrm{CO})=134.9 \mathrm{pm} . d(\mathrm{OO})=157.6 \mathrm{pm}), and (\angle(\mathrm{FCF}) 109.05^{\circ}) were derived. á 1994 Academic Press. Inc.