Nimesh R. Patel

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.

Highly fluorinated tetrazanes and other polynitrogen compounds

Abstract Highly fluorinated tetrazanes and cyclic, polycyclic and acyclic high nitrogen compounds are thermally and hydrolytically stable and, in general, shock insensitive materials. They are slightly volatile, colorless liquids which are only very slightly soluble in most solvents. Their synthetic routes are straighfforward but, as is typical of the chemistry of compounds which contain fluorine, there is always sufficient of the unexpected to tweak the imagination.

Nucleophiles useful for the transfer of fluorinated moieties to organic and inorganic substrates

Abstract The reactions of R f Si(CH 3 ) 3 (Rf = CF 3 , C 2 F 5 , C 3 F 7 ) with a variety of fluorinated organic and inorganic substrates containing a sulfur- or carbon-oxygen double bond have received some attention [1,2]. In order to extend our work, we have synthesized several interesting new as well as previously reported perfluoroalkyl and perfluoroaryl silanes. These reactive materials can be used effectively to replace directly active fluorine atoms bound to carbon with a number of fluorinated moieties, e.g., polyfluorinated polynitrogen compounds containing perfluoroaryl groups are prepared simply by using these silyl reagents. This powerful technique provides a direct route to previously known compounds, thus making them readily available for further study, as well as to a variety of heretofore unknown compounds. The reaction chemistry of these silanes with carbon-fluorine bonds will be discussed, and characterization of selected products will be presented.

Highly fluorinated high nitrogen compounds

Abstract Compounds that contain large amounts of nitrogen concomitantly with polyfluoroalkyl and perfluoroalkyl substituents normally are inert materials that exhibit excellent hydrolytic and thermal properties. We have reported the synthesis of a variety of new polyfluoroalkyl and perfluoroalkyl secondary and tertiary amines, tetraazanes, and highly fluorinated-nitrogen heterocycles [1]. Currently, repeated chlorofluorination and photolysis reactions of the rather intractable CCl 2 NCCl 2 CCl 2 NCCl 2 have led us through a variety of new compounds to the new stable hydrazine, Just as is the case for R f NSF 2 and R f NCF 2 , bis(polyfluoralkoxy)sulfimides and bis(polyfluoroalkoxy)carbimides behave differently under similar reaction conditions, viz., New diethers as well as polynitrogen compounds are possible base on the latter reaction.