Alkyl-2,2,2-trifluoroethyl selenides, RSeCH 2CF 3 (R=CH 3, C 2H 5, n-C 3H 7, n-C 4H 9, s-C 4H 9, t-C 4H 9) have been prepared in good yields by reacting alkyl selenolate anions RSe −, generated by the reduction of dialkyl diselenides with metallic sodium in liquid ammonia, with 1-iodo-2,2,2-trifluoroethane. Some of these bivalent selenides have been oxidized to their corresponding tetravalent selenium compounds, viz. CF 3CH 2(R)SeX 2 (X=Cl or Br) with halogens. The compounds have been characterized by elemental analysis, IR, 1H, 13C{ 1H}, 19F and 77Se{ 1H} NMR and mass spectral studies.