Acylations of Pentafluorosulfanylamine, SFSNHz - American Chemical

JOSEPH S. THRASHER, JON L. HOWELL, and ALAN F. CLIFFORD*. Received June 4, 1981. Acylation of SF5NH2 with select acyl halides has produced the ...
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Inorg. Chem. 1982, 21, 1616-1622

1616

knowledge Professor K. Seppelt for his assistance in this work and the Alexander von I-hmboldt Stiftung for a research

different from FN=SF4 and CH2=SF4 in this regard. Acknowledgment. This research was supported by funds from Deutsche Forschungegemeinschaft (H.H.E.), the US. Army Research Office, and the National Science Foundation (D.D.D.). Miss B. Saul is acknowledged for obtaining the Raman and infrared spectra. D.D.D. also wishes to ac-

Registry No. SFSNCIF, 74542-21-5; SFSNHF, 74542-22-6; FN=SF~, 74542-20-4; SF,=N, 15930-75-3; CIF, 7790-89-8; F2, 7782-41-4; TFA, 76-05-1.

Contribution from the Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061

Acylations of Pentafluorosulfanylamine, SFSNHz JOSEPH S. THRASHER, JON L. HOWELL, and ALAN F. CLIFFORD* Received June 4, 1981

Acylation of SF5NH2with select acyl halides has produced the corresponding N-pentafluorosulfanyl amides. The best yields were obtained in the reactions of acyl halides containing electron-deficient carbonyls. The first liquid pentafluorosulfanylcarbamyl derivative SF5NHC(0)F was prepared by the reaction of equimolar quantities of NSF,, COF,, and anhydrous HF. The reaction of SF,NH2 with ClC(0)CF2CF2C(O)Clproduced not only the expected diamide * [SF5NHC(0)CF212but also the novel cyclic imide SFsNC(0)CF2CF2C(O). Other N-pentafluorosulfanyl amides were prepared from the reaction of SFsNCO with suitable carboxylic acids. Several of the N-pentafluorosulfanylamides synthesized were allowed to react with PCl, to produce the corresponding chloro imines. The compound SF5NHC(0)NHSF5was also found to react with PCIs to produce the carbodiimide SF5N=C=NSFS. The products isolated were characterized by infrared and NMR spectroscopy, mass spectrometry, and elemental analysis.

Introduction In recent years there has been considerable interest in the synthesis and characterization of compounds containing fiveand six-coordinate sulfur(VI).*-ll This interest includes compounds containing sulfur as the central atom surrounded by five or six ligands as well as those employing six-coordinate sulfur as a functional group (e.g., the pentafluorosulfanyl group, SF5). (CH3)3C*

cF3 CF,

SF4==NCH3

SFSN

Compounds containing the pentafluorosulfanyl group are of ( 1 ) Shreeve, J. Israel J . Chem. 1978, 17, 1 and references within. (2) Glemser, 0.; Mews, R., Angew. Chem. 1980, 92, 904; Angew. Chem., Int. Ed. Eng. 1980, 19, 883 and references within. (3) Martin, J. C.; Perozzi, E. F. Science (Wushington, D.C.) 1976, 191 (4223), 154 and references within. (4) Martin, J. C. Top. Org. Sulphur Chem. Plenary Lect. Int. Symp. 8th 1978, 187-206 and references within. (5) Kitazume, T.; Shreeve, J. M. J. Am. Chem. SOC.1978, 100, 492. (6) Kitazume, T.; Shreeve, J. M. J . Chem. Soc., Chem. Commun. 1978,

1545. (7) Mews, R. Angew. Chem. 1978,90,561; Angew. Chem., Int. Ed. Engl. 1978, 17, 530. (8) DesMarteau, D. D.; Seppelt, K. Angew. Chem. 1980, 92, 659; Angew. Chem., Int. Ed. Engl. 1980, 19, 643. (9) Kleeman, G.; Seppelt, K. Angew. Chem. 1978,90,547; Angew. Chem., Int. Ed. Engl. 1978, 17, 516. (10) Sekiya, A.; DesMarteau, D. D. Inorg. Chem. 1980, 19, 1330. (1 1) Seppelt, K. Angew. Chem. 1976,88, 56; Angew. Chem., Inr. Ed. Engl. 1976, 15, 44.

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0020- 1669/82/ 132 1 16 16$01.25/0

particular interest since they often possess the advantageous properties of the parent compound sulfur hexafluoride. These properties include a high group electronegativity, a large steric bulk (greater than than of F or CF,), a nonfluctional hexacoordinate stereochemistry, and high thermal and hydrolytic stability. While investigations of carbon- and oxygen-substituted SF6 derivatives have been carried out in other laboratories, we have for sometime been investigating those compounds containing the N-pentafluorosulfanyl linkage. Along these lines we wish to report our results in the synthesis and characterization of several new SF,N< compounds as well as an alternate synthesis of several previously reported SF,N< compounds. Three types of reactions have been investigated: the acylation of SF5NH2,the reaction of SF,NCO with carboxylic acids, and the conversion of NSFS amides to chloro imines by reaction with PC&. Prior to this investigation two methods for the synthesis of compounds containing pentafluorosulfanyl-nitrogen-carbon linkages had been reported. The first, reported by Tullock et al., involves the photolytically induced free radical reaction between SFsCl and selected nitriles.I2 This reaction is limited in scope and provides only low yields of these materials. The chloro pentafluorosulfanylimines produced can further react to give secondary amines or alternate imines as shown by the two examples in Scheme I.l29l3 Scheme I SFSCl + RfCN A SFSN=C(Cl)Rf

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SFSN=C(Cl)Rf + H F SF5N=C(Cl)Rf + NaN,

NaF

SFSNHCFzRf SFSN=C(N,)Rf

(1)

(2) (3)

(12) Tullock, C. W.; Coffman, D. D.; Muetterties, E. L. J . Am. Chem. SOC. 1964,86, 357.

0 1982 American Chemical Society

Inorganic Chemistry, Vol. 21, No. 4, 1982 1617

Acylations of SFSNH2

The other method, reported by Shreeve and c o - w ~ r k e r s , ~ ~ *in ~ ~order to produce the corresponding N-pentafluorosulfanyl derivative. This amide SF,NHC(O)CF,, a white solid with employs nucleophilic displacement of fluorine from a hexaapproximately 10 torr vapor pressure at 25 "C, was produced coordinate sulfur(V1) species. They have found that the choice in 79% yield and was identified by its NMR, IR, and mass of nucleophiles is extremely limited. Only (CH3)3SiN(CH3)2 spectral analyses. or LiN==C(CF3)2has been found to react with hexacoordinate sulfur(V1) compounds in such a way as to preserve the high CF,C(O)F SF,NH2 SF,NHC(O)CF3 + H F (7) coordination number and oxidation s t a t e a l l others either fail to react or cause reduction of the sulfur. Also, these reactions The isolation of SFSNHC(0)CF3from the above reaction proceed only under controlled low-temperature reaction conled us to speculate that SF,NHC(O)F could be made from ditions. Scheme I1 gives examples of reactions involving both the reaction of SFSNH2and COF2. Previously the only nu~leophi1es.l~ The example described in eq 4 has been reproduct isolated from this reaction was SF5NC0 (eq 8);21 ported only for the reaction of the silane with SF5Clor SF5Br. COF2 + SFSNH2 SFSNCO + 2HF (8) The product shown in eq 5 contains a pentacoordinate sulfur(V1) and is probably formed from an intramolecular 1,3however, the reaction mixture was always placed on sodium fluoride shift since the stereochemistry is fixed and the molfluoride to remove the excess HF. We have found that if an ecule nonfluctional. This product could probably be coordiequimolar reaction mixture of NSF,, COF2,and AHF is exnately saturated by the addition of hydrogen fluoride as in the amined without being placed on NaF, the product SF,NHCreported reaction of H F and CF3SF3=NCF3.16 ( 0 ) F is obtained in high yield. This product is a colorless liquid, whereas all previously reported pentafluorosulfanylScheme 11 carbamyl derivatives have been white crystalline solid^.'^-^'-*^ SF5Cl + (CH3)2NSi(CH3)3 The compound SF,NHC(O)F has a vapor pressure of aptruns-C1SF4N(CH3),+ FSi(CH3), (4) proximately 50 torr at 25 OC and spontaneously loses HF when in contact with glass or NaF. SF5Br LiN=C(CF3)2 BL~F,=NCF(CF,)~ LiF The acylation of SF,NH2 by oxalyl chloride produced the (5) corresponding diamide SF,NHC(O)C(O)NHSF, in 78% yield, while acylation by perfluorosuccinyl chloride yielded not We have investigated methods which have a broader scope only the expected diamide [SF5NHC(O)CF2I2but also the than either of the two aforementioned methods. These methods, which are not limited to one or several specific novel cyclic succinimide SF5NC(0)CF2CF2C(O).The sucreagents, have allowed us to prepare several new compounds cinimide, obtained in 43% yield, is a white, extremely airsensitive solid with a vapor pressure of approximately 1 torr and to provide an alternate synthesis for several previously at 25 "C. Its identity was confirmed by exact mass specreported compounds. The scope of our investigation, as well trometry along with IR and NMR spectroscopy and E1 mass as a discussion of the characteristics of the new compounds, spectrometry. is included. The acylation of SF5NHzcan even be accomplished by Results and Discussion acetyl chloride and acrylyl chloride, but these seem to be the extreme limits of the synthetic method since low yields are Acylatim of SF5NH2 The present investigation shows that obtained in both reactions. The acrylamide SF,NHC(O)CSFSNH2reacts readily at room temperature with various acid H 4 H 2 is not the isolated product in the reaction with acrylyl chlorides and fluorides containing electron-deficient carbonyl chloride, as the HCl generated readily saturated the double groups to produce the novel N-pentafluorosulfanyl amides, bond to give SFSNHC(0)CH2CH2Cl(eq 9). The reaction SF,NHC(O)R. Since the reaction of NSF, and HF to produce SFSNH2has been shown to be an equilibrium reaction," CH2=CHC(O)Cl+ SFSNH2 SF,NHC(O)CH=CH, the SF5NH2used in these reactions was generated in situ. We + HCl SFSNHC(O)CHZCH2Cl (9) have also found by monitoring the reaction of NSF, and H F at -25 OC that within approximately 40 min the pressure of of SFSNH2with malonyl chloride did not yield a product the reaction mixture has returned to the vapor pressure of HF containing the pentafluorosulfanyl m ~ i e t y ,and ~ ~ no . ~ reaction ~ at that temperature.'* Therefore, the NSF, and H F were occurred between the amine and benzoyl chloride. allowed to react for a minimum of 35 min, and usually longer, Reactions of SF,NCO with Carboxylic Acids. The reaction prior to the addition of the acid chloride or fluoride. In several of SF5NC0with certain carboxylic acids provides an alternate of the reactions with acid fluorides only 1 equiv of HF/ 1 equiv synthetic method to the previously unknown SF,NHC(O)R of NSF, was used since an additional equiv of H F would be compounds. The reaction is believed to pass through a mixproduced as a byproduct in the reaction. ed-acid anhydride intermediate which readily loses COz to give Remarkably enough, the analogous acylation reactions of the corresponding N-pentafluorosulfanyl amide (eq 10); fluorosulfonamide, FS02NH2,have not been reported; howhowever, no attempts were made to isolate such intermediates ever, (trifluoroacetyl)fluorosulfonylimide,FSO2NHC(O)CF,, in the reactions being discussed. has been prepared via an alternate route19~20 as shown in eq SFSNCO + RCOOH [SF,NHC(O)O(O)CR] 6 . Thus, SFSNH2was first allowed to react with CF3C(0)F SFSNHC(0)R + C02 (10) CFjCOOH FS02N=PC13 Both CH,COOH and CH,=CHCOOH were found to reFSO*NHC(O)CF3 + O=PC13 ( 6 ) act readily with SF5NC0 at 25 OC. The yields of 98 and 35% for SF5NHC(0)CH3and SF,NHC(0)CH=CH2, respec-

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(13) (14)

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Logothetis, A. L. J . Org. Chem. 1964, 29, 3049. Kitazume, T.; Shreeve, J. M.J . Chem. Soc., Chem. Commun. 1976, 982.

Kitazume, T.; Shreeve, J. M.J . Am. Chem. SOC.1977, 99, 3690. Yu,S.L.; Shreeve, J. M.Inorg. Chem. 1976, 15, 14. Clifford, A. F.; Duncan, L. C. Inorg. Chem. 1970, 5, 692. Clifford, A. F.;Anderson, P. J., unpublished research. Heinze, P. R. Dissertation, GBttingen, 1968. (20) Roesky, H. W.; Giere, H. H.; Babb, D. P. Inorg. Chem. 1970,9, 1076.

(15) (16) (17) (18) (19)

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(21)

Duncan, L. C.; Rhyne, T. C.; Clifford,A. F.; Shaddix,R.E.; Thompson, J. W. J . Inorg. Nucl. Chem., Suppl. 1976, 33.

Shaddix, R.E. Master's Thesis, Virginia Polytechnic Institute and State University, 1974. (23) Thrasher, J. S.;Howell, J. L.; Clifford, A. F.; unpublished research. (24) The reaction of SF,NH2 and malonyl chloride was again repeated with similar results. (22)

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Thrasher, Howell, and Clifford

Pentafluorosulfanyl Amides and Imides 68.7 68.7 -8.3 87.4 73.5 -59.6 77.1 67.8 81.5 13.1 82.3 72.9 76.2 69.1 69.3 67.7 81.0 72.8 81.5 72.6 89.8 75.6 -114.4

156.7 157.3 157.9 153.7 158.2 158.9 158.9 159.7 159.6

Freon 11 Me,SOd, Me,SOd, Me,SOd, Me,SO-d6 Me,SO-d, acetone Me,SO-d, Me,SOd6 Me,SOd,

59.6

156.5

CDCI,

155.4 156.0 153.2 157.6

cc1, CCI, cc1,

73.2

SF,N=C(CI)CF, SF,N=C(Cl)CH, [ SF,N=C(Cl)f, SF,N=C=NSF,

tively, make this a better synthetic method for preparing these amides than the corresponding acylations of SFsNH2. Unlike the room-temperature reaction of CH3COOH or CH2=CHCOOH with SFsNCO, a temperature of 60 OC was required before malonic acid would react with SFSNCO. In this case both the amideacid SFsNHC(0)CHzCOOHand the diamide SFSNHC(0)CH2C(O)NHSFswere obtained from the product mixture. We had previously synthesized this diamide from the reaction of SFsNH2with carbon suboxideZ2as shown in eq 11.

+ C302 SFSNHC(O)CH2C(O)NHSFs 2SFsNCO + CHZ(COOH)2 SFSNHC(O)CH2C(O)NHSFs + 2C02 2SFsNH2

-126.7

Chioro Pentafluorosulfanvlimines and -carbodiimides -66.7 64.0 59.i 69.8 58.3 65.1 59.5 65.6 82.1

+

(1 1)

+

(12)

Pentafluorosulfanylisocyanate failed to react with carboxylic acids in which the carboxylate group is electron deficient, including CC1,COOH and CF300H. It also failed to react with PhCOOH presumably due to steric hindrance as well as the weakly nucleophilic nature of the carboxylate group. The sulfonyl analogue, fluorosulfonyl isocyanate (FS02NCO),has been reported to react with CC13COOHZSbut not with CF3COOH,20thus indicating that this isocyanate is slightly more reactive than SFSNCO. The compound C1SO2NCOhas also been reported to react with PhCOOHZ to yield ClS02NHC(0)Ph. Only the N-(pentafluorosulfany1)benzamides could not be prepared by either synthetic method, but work is continuing in our laboratory on synthesizing this other class of compounds. Chloro Imines. Pentafluorosulfanylimines were prepared from PClSand the appropriate amide (eq 13). This reaction CCI,

SFsNHC(O)R + PClS SF,N=C(Cl)R

+ POC13 + HCl

(13)

has also been successfully employed by Roesky20~2s~27 in the synthesis of N-fluorosulfonylimines and is a general method for the synthesis of chloroimines from amides.% This synthetic procedure provides an alternate method for the preparation of chloro pentafluorosulfanylimines previously unavailable except through the photolytic method of Tullock et al.12 Of (25) (26)

Roesky, H. W.; Giere, H. H. Chem. Ber. 1969, 102, 3707. Graf, R. Angew. Chem. 1968,80, 179; Angew. Chem., Int. Ed. Engl.

(27)

Roesky, H. W. Angew. Chem. 1969,81, 119; Angew. Chem., Int. Ed.

CCI,

Table 11. I9F Chemical Shifts of the Sulfonyl Fluorine in FSO,NHC(O)CX, and FSO,N=C(CI)CX, compound^^^^^^ compd FSO,NHC(O)CH, FSO,NHC(O)CH,Cl FSO,NHC(O)CHCI, FSO,NHC(O)CCI, FSO,NHC(O)CH,F FSO,NHC(O)CF,

SF shift 51.4 52.4 54.9 53.3 53.8

compd

SF shift

FSO,N=C(Cl)CH, FSO,N=C(Cl)CH,Cl FSO,N=C(Cl)CHCl, FSO,N=C(Cl)CCI, FSO,N=C(CI)CH,F FSO,N=C(Cl)CF,

53.8 54.9 56.0 57.3 54.5 55.2

the several representative amides treated with PCls, only the product SFsN=C(Cl)CH3 had not been previously synthesized. The chloro imines are liquids at room temperature and are surprisingly stable toward hydrolysis.20,28 One amide not prepared by the previously described procedures, of long term interest to us, is SFsNHC(0)NHSFs.21 This amide also reacts with PCls producing the carbodiimide SFSN=C=NSF5. Equation 15 shows a method previously CCI,

+

SFsNHC(0)NHSFS PCls 60'~SF,N=C=NSF, POC13 SFsNH2

+ SFsN=CC12

+

+

+ 2HC1 (14) SFSN=C=NSFS + 2HC1 (15)

reported by us29for the synthesis of this carbodiimide. The new procedure has allowed a more complete analysis of this compound. The physical characteristics for the carbodiimide are included with those of the chloro imines. NMR Parameters. The fluorine-19 NMR spectrum of a pentafluorosulfanyl group is a powerful diagnostic proof for the positive identification of compounds containing this moiety. This is due to its distinctive AB., splitting pattern. All of the compounds described in this paper exhibit this distinctive splitting pattern, and some interesting observations have emerged from the study of the 19FNMR spectral parameters. The 19F NMR spectrum of SFSNHC(0)F exhibits an atypical AB4X pattern seen before only in SFs0F.30 The spectrum is very similar to that of SF50F initially described by Cady et al.30aas a doublet and an asymmetrical sextet. Cady30bas well as Harris and Packer3&have since shown that the spectrum of SFsOF consists of many more lines and that the overall appearance is merely a consequence of the ABJ

1968, 7, 172.

Engl. 1969, 8, 136. (28) "The Chemistry of the Carbon-Nitrogen Double Bond"; S. Patai, Ed.;

Interscience: New York, 1970; p 601

(29) (30)

Clifford, A. F.; Shanzer, A. J. Fluorine Chem. 1976, 7, 65. (a) Dudley, F. B.;Shoolery, J. N.; Cady, G. H. J. Am. Chem. Soc. 1956, 78, 568. (b) Cady, G. H.; Merill, C. I. J. Am. Chem. SOC.1962,84, 2260. (c) Harris, R. K.; Packer, K. J. J. Chem. SOC.1962, 3077.

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Acylations of SFSNH2

Another example of this with a unique difference is reported here. Analysis of the 19FNMR of [SF,NHC(O)], taken in acetone and Me2SO-d6shows that not only are the chemical shifts different but that the axial fluorine is substantially more affected by the change of solvents than are the equatorial fluorines. This solvent effect is most likely due to an interaction which disrupts hydrogen bonding in the compound. As shown in Table I, this solvent-induced magnetic disruption is of sufficient strength that the chemical shift of the equatorial fluorines changes by 1.4 ppm, while the chemical shift of the fluorine trans to the amide nitrogen changes by 6.9 ppm. This effect has been observed previously by us36and is the only report of the nonrelative shifting of the axial and equatorial fluorine resonances of a pentafluorosulfanyl group as an effect of solvent. The 13CNMR spectrum of [SF5NHC(0)12also proves to be interesting, especially when compared to that of (SF,NH),CO. In [SF,NHC(O)], the carbon resonance centered at 156.1 ppm is a quintet (JSF,x= 3.4 Hz) due to coupling with four equatorial fluorines of an SF, group, while in (SF5NH),C0 the carbon resonance at 161.i ppm is a sharp singlet. These observations may be best explained by considering "through-space" coupling with the fact that in SF5X compounds, where X contains fluorine, lJsxl is always much larger than Another important, and as yet unexplained, feature of compounds containing the pentafluorosulfanyl moiety involves the relative chemical shifts of the axial and equatorial fluorines 84.6 75.2 65.8 56.4 with respect to each other. As shown in Figure 1, the resoCHEMICAL SHIFT (PPM) nance of the axial fluorine in both amides appears downfield from the resonance of the equatorial fluorines, while the opFigure 1. I9F NMR spectra comparison of the sulfur(V1)-fluorine posite is true for the succinimide. This is also the case when region in SF5NHC(0)CH3, SF5NHC(0)CF3,and SF,NC(O)Ccomparing the chloro imines to the carbodiimide as shown in F2CF2C(0)(relative to CC1,F). Table I. Generally the resonance of the axial fluorine in an SF5-nitrogen compound appears farthest downfield; however, spin system. Several other pentafluorosulfanyl compounds, there is a reasonable number of exceptions, including SF5including SF500SF5,SF500CF3,and SF5SF5,have also been N=C=O?' SF5N=C=S?3 SF5N=SF2,38SF5N=S(0)F2,39 shown to exhibit atypical AB4 patterns due to the small and SF5N(CF3)2.40No unified theory has yet been proposed chemical shift difference between the A and B n ~ c l e i . ~ ~ .or~ reported ~ to explain these observations. It is widely known that 19FNMR chemical shift values vary Infrared Spectra. All of the amides exhibit the N-H significantly even in compounds containing slightly different stretching frequency in the 3430-3 180-cm-' region, as well substituents. This effect can be seen in the case of the fluoas the carbonyl amide I stretch in the 1830-1690-cm-' region rosulfonyl amides and as shown in Table 11. The with the expected higher energy shift with increasing elecsulfonyl fluorine is deshielded, sometimes nonuniformly, by tronegativity of the substituent. For example, the amide I the introduction of chlorine and fluorine substituents as much stretch of SF,NHC(O)F has the highest frequency at 1830 as five bonds away. A similar effect is observed on the cm-l followed by the amide I stretch of SF5NHC(0)CF3at chemical shifts of the axial and equatorial fluorines of the 1800 cm-'. The amides also show the characteristic S-F pentafluorosulfanyl amides and imines shown in Table I; stretching and wagging frequencies of the SF5group. These however, the axial fluorine is often more influenced by a appear at 950-830 and 600 f 12 cm-I, respectively. change of substituents. This is especially clear when one The pentafluorosulfanylimines show a strong N=C examines the S(V1) region of the 19F NMR spectrum of both stretching frequency in the high 1600-cm-' region which is SF5NHC(0)CH3and SF,NHC(0)CF3 as shown in Figure typical of this type of compound. They also show the char1. Since the downfield shifts of the axial and equatorial acteristic S-F stretching and wagging frequencies of the SFS fluorine resonances in SF5NHC(0)CF3are not relative, the group. The compound SF5N=C=NSF5 also has the charoverall appearance of the splitting pattern changes remarkably acteristic SF5 bands as well as the band normally associated as the SF5group moves toward an AX4 spin system. The fact with the N=C=N group4I (2154 cm-l). that the axial fluorine is often more influenced by substitution in SFsR compounds has been observed by 0 t h e r s ~ ~ and 9 ~ex(35) (a) Evans, D. F. Proc. Chem. SOC.1958, 115. (b) Glick, R. E.; Ehplained as a trans effect.34 renson, S. J. J. Phys. Chem. 1958,62, 1599. (c) Evans, D. F. J . Chem. Soc. 1960,877. (d) Johannesen, R. B.; Brinckman, F. E.; Coyle, T. D. Several reports have appeared in the literature concerning J . Phys. Chem. 1968, 72, 660. (e) Emsley, J. W.; Philip, L. Mol. Phys. significant solvent effects on I9F NMR chemical shifts.35 1966, 11, 437.

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SF5NHC(0)CH3

IJAxI.32337

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(31) (a) Merrill, C. I.; Cady, G. H. J . Am. Chem. SOC.1961,83, 298. (b) Merrill, C. I.; Williamson, S. M.; Cady, G. H.; Eggers, Jr., D. F. Inorg. Chem. 1962, I , 215. (32) Finer, E. G.; Harris, R. K. Spectrochimica Acta, Parr A 1968, 24A, 1939. (33) Boden, N.; Emsley, J. W.; Feeney, J.; Sutcliffe, L. H. Trans. Faraday SOC.1963, 59, 620. (34) Seppelt, K. Z . Anorg. Allg. Chem. 1973, 399, 65.

(36) Clifford, A. F.; Thrasher, J. S.; Newman, C. R.; Maurer, D. E.; Howell, J. L., paper presented at the 178th National meeting of the America Chemical Society, Honolulu, HI, Aug 1979. (37) Rogers, M. T.; Graham, J. D. J . Am. Chem. SOC.1962, 84, 3666. (38) Cohen, B.; Hooper, T. R.; Peacock, R. D. J . Chem. Soc., Chem. Commun. 1965, 32. (39) HBfer, R.; Glemser, 0. Z. Anorg. Allg. Chem. 1975, 416, 263. (40) Dobbie, R. C. J . Chem. Soc. A 1966, 1555. (41) (a) Khorana, H. G. Chem. Rev. 1953, 53, 145. (b) Meakin, G. D.; Moss, R. J. J . Chem. SOC.1957, 993.

1620 Inorganic Chemistry, Vol. 21, No. 4, I982

Thrasher, Howell, and Clifford

The compounds synthesized were analyzed by infrared and nuclear magnetic resonance spectroscopyand mass spectrometry and where possible by C, H, N, and S analysis. An all-Pyrex glass high-vacuum system was employed for handling the reactants and products except for anhydrous H F (AHF) which was handled on a metal vacuum system. Infrared spectra were obtained on a Beckman 20A-X infrared spectrophotometer, either on gases, pressure 1-100 torr, or on mulls in either halocarbon or mineral oil. Mass spectra were obtained on either a Hitachi Perkin-Elmer RMU-7 mass spectrometer, a Finnigan Model 3200 quadrupole mass spectrometer,or a Varian MAT 11 2 high-resolution mass spectrometer using either a solid inlet probe or a controlledgas-flow inlet. The I9Fand 'H NMR spectra were taken on either a JEOL PS-100 or a Varian EM-390 nuclear magnetic resonance spectrometer using CC13F and (CH,),Si, respectively, as internal standards. The I3C NMR spectra were taken on a JEOL FX 6 0 4 nuclear magnetic resonance spectrometer using Me2SO-d6 as an internal standard. Elemental analyses were obtained from the Chemistry Department's Perkin-Elmer 240 elemental analyzer or from Galbraith Laboratories, Knoxville, TN. Melting points were taken on a Mel-Temp apparatus and are uncorrected. All solvents and reagents were distilled or sublimed prior to use. Phosphorus pentachloride was used only in an inert (Ar) atmosphere box and was not purified prior to use. The compounds COFZ,,~ CF3C(0)F$3SFSNCO,Z1and SF,NHC(O)NHSF?' were synthesized and purified by known literature methods. The compound SFSNH2I7 was produced in situ from the reaction of NSF3 and HF. Preparation of SF,NHC(O)F. In a typical reaction, 150 mmol each stainless-steel of NSF3, COF2, and H F were condensed into a 75" cylinder at -196 OC. After the mixture was allowed to react for 5 days at room temperature, the volatile components were transferred onto a NaF scrubber while the reaction cylinder was held at -50 OC. The product could then be removed from the cylinder as a colorless liquid. The SF,NHC(O)F has a vapor pressure of 50 torr at 25 OC and spontaneously loses H F when in contact with glass or NaF. The yield (- 50%) was determined by removing the product to a NaF scrubber for several hours and then measuring the quantity of SFsNCO recovered. IR (capillary film): 3260 (vs), 2980 (m), 2720 (w), 1830 (vs), 1500 (vs), 1350 (w), 1215 (vs), 875 (vs), 790 (m), 750 (m), 705 (m), 655 (m), 605-575 (s) cm-I. Mass spectrum (70 eV) m/e (relative intensity): 170 [M - F]' (0.7), 169 [M - HF]' (15.3), 150 [SF4NCO]+(34.4), 127 [SF,]' (100.0), 108 (7.4), 104 (9.3), 103 (3.2), 89 (50.0), 70 (16.0), 51 (7.8), 47 [COF]' (84.4), 44 (31.3), 43 (3.4), 42 (7.4). 'H NMR: 6 9.28 (s, NH). Anal. Calcd for CHNSF,O: C, 6.35; H, 0.53; N, 7.54; S, 16.93. Found: C, 6.41; H, 0.48, N, 7.54; S, 17.58. Preparation of SF,NHC(O)CF,. Gaseous NSF3 (10.0 mmol) and H F (0.25 mL, 12.5 mmol) were condensed into a Kel-F reactor at -196 OC and were allowed to react at room temperature. After 12 h, CF3C(0)F (10.0 "01) was condensed into the reaction vessel and the solution was warmed slowly to ambient temperature. Within the period of 1 week a product had precipitated from the reaction mixture. The volatile products were then removed to a NaF scrubber while the temperature of the reaction vessel was maintained between -60 and -15 OC. The product remaining in the reaction vessel was then further purified by trap-to-trap distillation, the -30 OC trap retaining the SF5NHC(0)CF3(7.9 mmol); 79.0% yield. The compound is an easily sublimable white solid with a vapor pressure of 10 torr at room temperature; mp 49-51 OC. IR (gas): 34.30 (s), 1800 (s), 1485 (s), 1310 (m), 1230 (s), 1185 (s), 1130 (s), 950-875 (s), 780 (w), 730

(w), 665 (m), 612 (m), 590 (w), 560 (w) cm-I. Mass spectrum (70 eV) m/e (relative intensity): 239 M' (