The syntheses of three acyclic (fluorosulfonyl)− or ((trifluoromethyl)sulfonyl)−nitrogen derivatives and their crystal and molecular structures are reported. The structures of bis((trifluoromethyl)sulfonyl)amine (1; (CF3SO2)2NH) and the corresponding anion in magnesium hexaaquo bis((trifluoromethyl)sulfonyl)amide dihydrate (2; [Mg(H2O)6][(CF3SO2)2N]2·2H2O) shed some light on the observed high gas-phase acidity of (CF3SO2)2NH. Extensive electron delocalization in the anion [(CF3SO)2N]- from planar, sp2-hybridized nitrogen into 3d orbitals of sulfur results in a noticeable shortening of the S−N bond on deprotonation. Similar electron delocalization is observed for the third compound, bis(bis(fluorosulfonyl)amino)sulfur (3; (FSO2)2NSN(SO2F)2), which features planar nitrogens with nearly six equidistant S−N bonds and extremely short S−O and S−F bonds. Compounds 2 and 3 have not been reported previously. Their unexpected, accidental formation and their characterization will be discussed. Compound 1 crystallizes in the space group Pccn (No. 56) with a = 16.404(3) Å, b = 5.535(1) Å, c = 9.557(2) Å, and Z = 4. Compound 2 crystallizes in the space group P21/n (No. 14) with a = 6.400(1) Å, b = 14.300(1) Å, c = 14.421(1) Å, β = 97.45(1)°, and Z = 2. Compound 3 crystallizes in the space group P21/c (No. 14) with a = 12.762(1) Å, b = 6.744(1) Å, c = 13.627(1) Å, β = 91.42(1)°, and Z = 4.

Since the days of the "Manhattan Project" our knowledge of the chemistry of fluorine-containing compounds has increased tremendously. At first only considered out of curiosity, this area of research bordering between inorganic and organic chemistry has developed from modest beginnings to such a complexity of interesting ramifications that it would be very difficult to review all aspects in detail. The motivating force behind the developments in this field were, above all, the unusual properties the numerous compounds acquire on introduction of fluorine substituents. The spectrum of unusual modes of behavior extend from extreme stabilization in fluorine-containing polymers and blood-substitutes to drastic increases in reactivity in pharmacologically and phytomedicinally active substances and in dyes. Moreover, one physical peculiarity of the fluorine atom, its magnetic moment, opens a new route to the decyphering of metabolic processes.-Parallel to the ever increasing number of fluorinated compounds there has been a concomitant increase in the variety of methods of synthesis and reagents, which is frequently difficult to overview in entirety, even for the specialists. Older, simple methods such as halogen metathesis with metal fluorides and electrofluorination are being refined as far as higher selectivity is concerned, and completely new, very reactive substances such as hypofluorites and noble-gas fluorides enable fascinating reactions on complex substrates, e. g, steroids and nucleobases. The present review is an attempted documentation and classification of the methods as well as a critical appraisal, not least from the standpoint of efficiency and economic aspects.