The preparation of HN(SO2F)(2) was achieved conveniently by fluorination of HN(SO2Cl)(2) with SbF3. Reactions of Hg[N(SO2F)(2)](2) with fluoroalkyl iodides RI (R = i-C3F7CH2CH2 and CF3CH2) gave i-C3F7CH2CH2N(SO2F)(2) (1) and CF3CH2N(SO2F)(2) (2). The chlorination of Hg[N(SO2F)(2)](2) provided a high-yield method of synthesizing the well-known ClN(SO2F)(2). N-alkylation of ClN(SO2F)(2) with fluorinated ethenes CF2=CHal(2) (CHal(2) = CF2, CFCl, and CCl2) resulted in the formation of CF2ClCF2N(SO2F)(2) (3), CF2ClCFClN(SO2F)(2) (4a, major), CFCl2-CF2N(SO2F)(2) (4b, minor), and CCl3CF2N(SO2F)(2) (5). The synthesis of the first perfluoroalkyl-N(SO2F)(2) derivatives CF3N(SO2F)(2) (6), C2F5N(SO2F)(2) (7), n-C3F7N(SO2F)(2) (8), and n-C4F9N(SO2F)(2) (9) was accomplished with moderate-to-good yields by reacting ClN(SO2F)(2) with iodoperfluoroalkanes RFI (R-F = CF3, C2F5. n-C3F7, and n-C4F9). Similarly, Cln(SO2F)(2) reacted with CF3CH2I to give 2. Photolysis of ClN(SO2F)(2) with iodoperfluoroalkanes RFI (RF n-C3F7, and n-C4F9) gave 8 and 9 in low yields. HN(SO2F)(2) belongs to a monoclinic crystal system P2(1) (No. 4) : a = 5.1619(5) Angstrom, b = 7.8153(8) Angstrom, c = 6.8028(7) Angstrom, beta = 100.411(2)degrees, V = 269.92(5) Angstrom(3), Z = 2. HN(SO2Cl)(2) is monoclinic P2(1)/c (No. 14) : a = 7.7331(3) Angstrom, b = 10.0542(2) Angstrom, c = 9.3197(3) Angstrom, beta = 109.495(1)degrees, V = 683.07(4) Angstrom(3), Z = 3. CF3CH2N(SO2F)(2) is orthorhombic P2(1)2(1)2(1) (No. 19) : a = 11.1245(1) Angstrom, b = 28.8003(4) Angstrom, c = 7.7120 Angstrom, V = 2470.90(4) Angstrom(3), Z = 12.