Robert L. Kirchmeier

Some fluorine-containing nitrogen acids and their derivatives

Abstract Fluorine-containing nitrogen acids and their derivatives are highly useful compounds in a variety of applications. For example, the acids find practical use as electrolytes or additives for electrolytes in fuel cells, the lithium salt of (CF 3 SO 2 ) 2 NH is being developed for use in batteries, polymeric nitrogen acid electrolytes have been prepared, and the N -fluoro derivatives of some of the nitrogen acids are the most useful electrophilic fluorinating agents available. The first XeN bond was prepared using (FSO 2 ) 2 NH. Interest in these materials has been increasing rapidly over the last 10 years because of the large number of applications in which their physical and chemical properties make them suitable candidates for study.

Polyfluoroalkoxy and aryloxy cyclic phosphazenes : an alternative synthesis route to substitution reactions using siloxanes in the presence of fluoride ion catalysts

The first detailed investigations on the reactions of polyfluoromono- and dialkoxysilanes with cyclic fluorophosphazenes are carried out and compared with reactions of the nonfluorinated analogues. The method offers an easy and elegant route to the hitherto poorly studied bridged and dangling phosphazene compounds. For the first time a transformation of bridged phosphazene compount to spiro compounds is observed and monitored by 19 F NMR studies. An explanation is offered for the poor yields and inability to isolate bridged derivatives experienced by previous workers

Chemistry of Pentafluorosulfanyl Compounds

Publisher Summary Fluorinated compounds containing five- and six-coordinate sulfur are of considerable interest. They include those with sulfur as the central atom surrounded by five or six ligands as well as many with six-coordinate sulfur as a functional group, such as pentafluorosulfanyl, SF5. Compounds in which this group is present are of special interest because they often possess the advantageous properties of the parent compound, SF6, among which are a high group electronegativity, large steric bulk, a nonfunctional hexacoordinate stereochemistry, and high thermal and hydrolytic stability. These properties are manifested in various potential applications such as their use as solvents for polymers, as perfluorinated blood substitutes, as surface active agents, as fumigants, and as thermally and chemically stable systems. This chapter discusses the synthesis and chemistry of the various classes of pentafluorosulfanyl compounds, many of which are the subject of much ongoing research.

Reaction of hexafluorobenzene with trimethylsilyl ethers

Abstract Hexafluorobenzene reacts readily with a variety of trimethylsilyl ethers ROSiMe 3 (R=CF 3 CH 2 , FCH 2 CH 2 , H(CF 2 ) n ,CH 2 ( n =2, 4), CF 3 (CF 2 ) 6 CH 2 , CF 3 (CF 2 ) 5 CH 2 CH 2 , Me 3 SiOCH 2 CH 2 , C 6 F 5 OCH 2 CH 2 , C 6 H 5 , 4-FC 6 H 4 ) to give from mono- to hexapolyfluoroalkoxy- and polyfluoroaryloxy-benzenes. The structure of C 6 (OCH 2 CF 3 ) 6 has been confirmed by single-crystal X-ray analysis. The perfluorinated ether C 6 F 5 OCF 2 CF 3 may be synthesized from C 6 F 5 OCH 2 CF 3 by chlorination and subsequent fluorination with SbF 3 /SbCI 5 . The chlorination of 5,6,7,8-tetrafluoro-1,4-benzodioxane is also discussed.

Oxadiazoles with NF2-containing substituents

Abstract Oxalyl chloride was reacted with sodium-5-(difluoroamino)- difluoromethyltetrazolate or sodium-5-pentafluoroethyltetrazolate to form [R f CNNC(O) ] 2 [R f z NF 2 CF 2 ( 7 )], and with F 2 NCF 2 C(NH 2 )NOH to give [F 2 NCF 2 C(NH 2 )NOC(O)] 2 ( 5 ) which may be dehydrated to the 1,2,4-oxadiazole ( 6 ). Both sodium salts can be reacted with perfluoroacyl acid chlorides to form 2,5-disubstituted 1,3,4-oxadiazoles, R f CNNC(R f ′)O where R f ′ = NF 2 CF 2 and R f = CF 3 ( 8 ), C 2 F 5 ( 9 ), or C 3 F 7 ( 10 ); R f ′ = C 2 F 5 and R f = CF 3 ( 11 ) or C 2 F 5 ( 12 ).

Synthesis of fluorinated tertiary diamines and diazanes

Abstract A variety of fluorinated and partially fluorinated tertiary diamines and diazanes have been prepared from 1-[bis(trifluoromethyl)amtno]tetrafluoro-2- azapropene, which is obtained from the dimerization of 2-azapropene in the presence of CsF. Addition of ClF results in the formation of the tertiary diamine (CF3)2NCF2N(Cl)CF3. Insertion of alkenes and nitriles into the nitrogenchlorine bond, as well as photolytic reactions with SF5Cl and CF3C(O)Cl, occurs readily. Attempts to prepare diazanes that contain polyfluoroalkyl groups from polyfluoroalkoxy imines, e.g., RfNC(ORf′)2 (Rf  CF3, SF5; Rf′  CH2CF3, CH(CF3)2) resulted in breaking of the carbonnitrogen double bond on reaction of the imine with ClF to give RfNCl2 and F2C(ORf′)2. Similarly (CF3)2NC(OCH2CF3)NCF3 with ClF gives CF3NCl2 and (CF3)2NCF2OCH2CF3.

Synthesis and reactions of fluoroalkyl polynitrogen compounds

Thermally induced insertions into a single nitrogen-chlorine bond of (CF 3 ) 2 NCF 2 NCl 2 (1) by the olefins CF 2 =CClF, CF 2 =CHF, and CF 2 =CH 2 give rise to (CF 3 ) 2 NCF 2 N(Cl)CF 2 CCl 2 F (3) and (CF 3 ) 2 NCF 2 N(Cl)CX 1 X 2 CClF 2 (X 1 =F, X 2 =H (4); X 1 =X 2 =H (5)), respectively

The effect of fluorination in trimethylamine: gas-phase structures of CF3N(CH3)2 and (CF3)2NCH3

Abstract The molecular structures of CF 3 N(CH 3 ) 2 and (CF 3 ) 2 NCH 3 have been determined by gas electron diffraction. The following skeletal parameters ( r a distances and ∠ α angles) have been obtained for CF 3 N(CH 3 ) 2 : CF = 135.1(4) pm, NC H = 148.1(10) pm. NCf = 138.3(16) pm. C H NC H = 113.0(27)°, C H NC F = 111.9(9)°; (CF 3 ) 2 NCH 3 : Cpm, NC H = 147.8(13) pm, NC F = 142.0(8) pm, C H NC F = 116.8(13)°, C F NC F = 117.8(11)°. C H and C F are th methyl and trifluoromethyl carbon atoms, respectively. Experimental uncertainties are 3σ values and include possible systematic errors. The most surprising result is the large difference between the NC H and NC F bond lengths of about 10 and 6 pm in these compounds. All nitrogen bond angles increase concomitantly with increasing number of CF 3 groups. An attempt is made to rationalize the observed structural trends.

Nucleophilic substitution reactions of polyfluoroalkylsulfonamides

Abstract The sulfonamides CF 3 SO 2 N(CH 3 )Na and CF 3 SO 2 N(H)Na have been reacted with polyfluoro cyclic, acyclic and inorganic chlorine and bromine-containing species. Nucleophilic displacement of chlorine or bromine in 1,2-dichloroperfluorocyclobutene, 1,2-dichloroperfluorocyclopentene, benzyl bromide, cyanuric chloride and oxalyl chloride has been found to occur under mild conditions to give good yields of N-substituted polyfluoroalkyl and polyfluoroaryl sulfonamides. The effects of solvent and substrate structure on the conditions necessary for reaction to occur, and the yields obtained of the desired products are discussed.

Synthesis and characterization of per/polyfluorophenoxy derivatives of octachlorocyclotetraphosphazenes

Abstract Octachlorocyclotetraphosphazene was treated with various fluorinated phenols to form partially and completely substituted cyclotetraphosphazenes. The mono-substitution reactions were carried out using a base in benzene while for complete substitution sodium salts of the corresponding phenoxides were used. All compounds were characterized by 1 H, 19 F, and 31 P NMR, IR and mass spectroscopic methods. A crystal structure was obtained for N 4 P 4 (OC 6 F 5 ) 8 , and shows that the phosphazene ring is puckered. The angle of the planes N2P2N1P1N4 to N4P4N3P3N2 is 45.5° and the angle of the planes N1P1N4P4N3 to N3P3N2P2N1 is 43.8°.