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H.-J. Frohn et al. / Journal of Fluorine Chemistry 130 (2009) 301–307
mother liquor showed a negligible amount of pentafluorophe-
liquid nitrogen. The products were extracted with CH2Cl2 (1 mL).
The 19F NMR spectrum of the extract showed signals of C6F5I (8),
[(C6F5)2I][F(HF)n], 1-iodononafluorocyclohexene (9), 1-iodo-3-
oxopentafluorocyclohexa-1,4-diene (11), and 1-iodo-6-oxopenta-
fluorocyclohexa-1,4-diene (12) in the molar ratio 42:10:42:3:3
(overall yield ca. 72%) besides signals of secondary amounts of
unknown compounds.
nyl compounds. The precipitate was separated by decantation
and dried in vacuum at ꢀ20 8C to give a yellow product (46 mg).
Its solution in cold (ꢀ40 8C) MeCN (0.5 mL) presented 19F signals
of C6F5IF2, [C6F5IFꢂNCCH3][BF4], and [(C6F5)2I][BF4] (molar
ratio 47:42:11). Addition of mesitylene (0.11 mmol) and
maintaining at 20 8C overnight resulted in C6F5IF2, [(2,4,6-
C6H2(CH3)3)(C6F5)I][BF4], C6F5I, and [(C6F5)2I][BF4] (molar ratio
58:25:12:5) (19F NMR).
B. Dissolution of the yellow precipitate (68 mg), which was
obtained analogous from C6F5IF2 (63 mg, 0.19 mmol) and BF3
in PFP (0.5 mL), in cold (ꢀ20 8C) HF which contained water from
exposure to air (0.5 mL) gave a colorless solution of C6F5IF2
which contained [BF4]ꢀ (2:1, molar) (19F NMR).
1-Iodo-3-oxopentafluorocyclohexa-1,4-diene (11). 19F NMR
(CH2Cl2):
d
= ꢀ98.5 (ddd, 4J(F6,F2) = 10 Hz, 4J(F6,F4) = 10 Hz,
3J(F6,F5) = 25 Hz, 2F, F6,6), ꢀ103.3 (ddt, 4J(F2,F4) = 3.5 Hz,
5J(F2,F5) = 4 Hz, 4J(F2,F6) = 10 Hz, 1F, F2), ꢀ135.6 (ddt,
5J(F5,F2) = 3.5 Hz, 3J(F5,F4) = 5 Hz, 3J(F5,F6) = 25 Hz, 1F, F5), ꢀ152.9
(ddt, 3J(F4,F5) = 4 Hz, 4J(F4,F2) = 4 Hz, 4J(F4,F6) = 10 Hz, 1F, F4).
1-Iodo-6-oxopentafluorocyclohexa-1,4-diene (12). 19F NMR
(CH2Cl2):
d
= ꢀ90.9 (ddt, 4J(F2,F4) = 3 Hz, 5J(F2,F5) = 3 Hz,
4.6. Reaction of C6F5IF2 with BF3 in CH2Cl2
3J(F2,F3) = 26 Hz, 1F, F2), ꢀ115.2 (ddd, 4J(F3,F5) = 10 Hz,
3J(F3,F4) = 21 Hz, 3J(F3,F2) = 26 Hz, 2F, F3,3), ꢀ145.9 (ddt,
5J(F5,F2) = 3 Hz, 3J(F5,F4) = 4 Hz, 4J(F5,F3) = 10 Hz, 1F, F5), ꢀ147.2
(ddt, 3J(F4,F5) = 4 Hz, 4J(F4,F2) = 3 Hz, 3J(F4,F3) = 21 Hz, 1F, F4).
A FEP trap equipped with a magnetic stir bar was charged with
C6F5IF2 (165 mg, 0.50 mmol), CH2Cl2 (0.4 mL) and deposited in a
stainless steel cylinder which was attached to a stainless steel
vacuum line. After evacuation at ꢀ78 8C BF3 (ca. 2 mmol) was filled
in. The reaction mixture was stirred at ꢀ40 8C for 5 days. The excess
of BF3 was removed at ꢀ78 8C in vacuum (0.1 hPa) and the mother
liquor was separated from the yellow precipitate after centrifuga-
tion at ꢀ78 8C. The precipitate was washed with cold (ꢀ40 8C)
CH2Cl2 and dried in vacuum at ꢀ40 8C yielding a yellow solid
(27 mg). The 19F NMR spectrum of the latter in cold (ꢀ40 8C) MeCN
showed resonances of C6F5IF2, [C6F5IFꢂNCCH3][BF4], and
[(C6F5)2I][BF4] in a molar ratio of 26:53:21. The mother liquor
4.9. Reaction of C6F5IF4 with SbF5 in SO2ClF
C6F5IF4 (68 mg, 0.18 mmol) was added to the cold (ꢀ35 8C)
solution of SbF5 (158 mg, 0.73 mmol) in SO2ClF (0.55 mL) in one
portion to form a yellow solution. NMR measurements at ꢆ0 8C
revealed the formation of 3d. Following the solution was kept at
20 8C and became deep green within 20–30 min. After 2 h the
green solution was cooled to ꢀ20 8C, diluted with aHF (0.1 mL)
and poured onto ice which was treated with liquid nitrogen.
contained C6F5IF2
(
19F NMR).
Extraction with CH2Cl2 (1 mL) gave a solution of C6F5I,
[(C6F5)2I][F(HF)n], 1-iodononafluorocyclohexene (9), and iodoun-
decafluorocyclohexane (10) (molar ratio 53:4:26:17) (overall
yield ca. 78%) besides traces of unknown non-aromatic com-
pounds (19F NMR).
4.7. Reaction of C6F5IF2 and BF3ꢂNCCH3 with mesitylene
A solution of [C6F5IFꢂNCCH3][BF4] (0.28 mmol) obtained from
equimolar amounts of BF3ꢂNCCH3 and C6F5IF2 in MeCN (0.4 mL) at
ꢀ40 8C was treated with a cold (ꢀ40 8C) solution of mesitylene
(35 mg, 0.29 mmol) in CD3CN (0.1 mL). After 1 h at ꢀ40 8C,
volatiles were removed in vacuum, the residue was washed with
CH2Cl2 (3ꢅ 0.2 mL) at 20 8C and dried in vacuum. Salt [(2,4,6-
C6H2(CH3)3)(C6F5)I][BF4] was obtained in ca. 90% yield.
Iodoundecafluorocyclohexane (10). 19F NMR (CH2Cl2),
d:
ꢀ104.8 (d, 2J(F2a,F2e) = 292 Hz, 2F, F2a,6a), ꢀ125.0 (d,
2J(F2e,F2a) = 292 Hz, 2F, F2e,6e), ꢀ121.8 (d, 2J(F3a,F3e) = 289 Hz, 2F,
F3a,5a), ꢀ135.6 (d, 2J(F3e,F3a) = 285 Hz, 2F, F3e,F5e), ꢀ122.8 (d,
2J(F4a,F4e) = 285 Hz, 1F, F4a), ꢀ141.8 (d, 2J(F4e,F4a) = 285 Hz, 1F, F4e),
ꢀ144.6 (m, 1F, F1) ppm (cf. [34]).
[(2,4,6-C6H2(CH3)3)(C6F5)I][BF4] (14). 1H NMR (CD3CN):
d = 7.26
(m, 2H, H3,5), 2.65 (s, 6H, 2CH3 ortho), 2.35 (s, 3H, CH3 para). 19F
4.10. Reaction of C6F5I with SbF5 in SO2ClF
NMR (CD3CN):
d
= ꢀ120.9 (m, 2F, F2,6), ꢀ142.9 (tt,
3J(F4,F3,5) = 20 Hz,4J(F4,F2,6) = 6 Hz, 1F, F4), ꢀ155.8 (m, 2F, F3,5),
A. C6F5I (38 mg, 0.13 mmol) was added in one portion to the cold
solution (ꢀ50 8C) of SbF5 (96 mg, 0.44 mmol) in SO2ClF
(0.55 mL) to give a deep blue solution. The 19F NMR spectrum
(ꢀ30 8C) showed only resonances at 99.8 ppm (SO2ClF) and
broad resonances at ꢀ86 and ꢀ123 ppm (SbV–F). Warming to
20 8C caused the formation of a deep green solution. After 1.5 h
ꢀ149.2 (s, [BF4]ꢀ). 13C NMR (CD3CN):
d = 147.8 (dm,
1J(C,F) = 251 Hz, C-2,6; C6F5), 146.6 (dtt, 1J(C,F) = 260 Hz,
2J(C,F) = 13 Hz,
3J(C,F) = 5 Hz,
C-4;
C6F5),
138.9
(dm,
1J(C,F) = 259 Hz, C-3,5; C6F5), 84.6 (td, 2J(C,F) = 26 Hz, 4J(C,F) = 5 Hz,
2
C-1; C6F5), 146.8 (q, J(C,H) = 6 Hz, C-20,60; C6H2), 144.1 (m, C-40;
1
C6H2), 131.6 (dm, J(C,H) = 165 Hz, C-30, 50; C6H2), 121.9 (m, C-10;
at 20 8C, the 19F NMR signals of the cation [(C6F5)2I]+ (
d
= ꢀ117.7
C6H2), 27.0 (qm, 1J(C,H) = 129 Hz, ortho-CH3), 21.0 (qtm,
1J(C,H) = 128 Hz, 3J(C,H) = 4 Hz, para-CH3). 14 decomposed in a
closed capillary at 161 8C. The products were dissolved in cold
MeCN and gave C6F5I, C6H2F(CH3)3, and BF3ꢂNCMe in the molar
ratio 1:1.1:1.2 (19F NMR).
(F2,6), ꢀ133.8 (F4), and ꢀ151.2 (F3,5) ppm) were observed in
addition to the above-mentioned resonances. The solution was
kept at 20 8C overnight, cooled to ꢀ10 8C, diluted with aHF
(0.2 mL) and poured onto ice which was treated with liquid
nitrogen. After melting of the ice, the products were extracted
with CH2Cl2 (1 mL). The extract contained C6F5I and
[(C6F5)2I][F(HF)n] (74:26) (19F NMR).
4.8. Reaction of C6F5IF2 with SbF5 in SO2ClF
B. When the deep green solution of C6F5I (187 mg, 0.63 mmol) and
SbF5 (419 mg, 1.93 mmol) in SO2ClF (0.5 mL) was kept at 22 8C
over a period of 5 days a dark precipitate formed. The reaction
mixture was cooled to 0 8C and poured onto ice treated with
liquid nitrogen. After melting of the ice, the brown suspension
was extracted with pentane (1 mL). The rose extract showed
signals of C6F5I (0.24 mmol) (19F NMR). The aqueous phase was
saturated with Na[BF4] and [(C6F5)2I][BF4] (84 mg, 0.15 mmol)
was filtered off.
A solution of SbF5 (144 mg, 0.66 mmol) in SO2ClF (0.55 mL) was
cooled to ꢀ20 8C and solid C6F5IF2 (2) (84 mg, 0.25 mmol) was
added in a one portion to form a deep green solution. The 19F NMR
at ꢀ20 8C revealed the formation of [4-I-1,1,2,3,5,6-C6F6]+ (2c) (see
Table 2), When the solution was kept at 20 8C for 1.5 h 2c
disappeared in the 19F NMR and 9 and [(C6F5)2I]+ appeared.
Subsequently the reaction mixture was cooled to ꢀ15 8C, diluted
with aHF (0.1 mL) and poured onto ice which was treated with