Octachloroazulene
A R T I C L E S
hot water (50 mL), then dried over anhydrous MgSO
tion of the blue solution, the residue was further purified by sublimation
4
. After concentra-
argon, Schwesinger base 12 (285 µL, 0.923 mmol) and 3 mL anhydrous
THF were placed in the funnel. The mixture was cooled to -40 °C
with dry ice/acetonitrile slush. The base solution was then slowly added
during 0.5 h, and the mixture was kept at -40 °C with stirring for
at 70 °C/30 mTorr to afford 0.20 g of 10 as a blue solid: mp 138-139
1
2
-1
°
1
C (lit. 138-139 °C). Yield: 80%. IR (KBr, cm ): 1588, 1493,
412, 1306, 1227, 1125, 1096, 1017, 912, 855, 821, and 696. UV-vis
3
another 0.5 h. After addition of anhydrous CaCO (3.6 g, 36 mmol),
(
cyclohexane, nm): λmax 272 (27 000), 309 (40 900), 381 (5540), 399
the reaction mixture was warmed to room temperature and stirring was
continued overnight. Solvent was removed and the resulting dark green
residue was chromatographed on a column of silica gel (50 g, Acros,
0.035-0.07 mm), with hexane as eluent. After rotary evaporation a green
solid was obtained. HPLC showed the purity of the octachloroazulene
to be 95%. The material was further purified to 98% by recrystallization
(4530), and 678 (471).
1
,1,2,3,3,4,5,6,7,8-Decachloro-1,2,3,4-tetrahydroazulene (11). In
a 50 mL round-bottom flask, 5 (0.70 g, 2.6 mmol) was dissolved with
freshly distilled sulfuryl chloride (25 mL). The blue color of the solution
quickly turned to yellow. The solution was irradiated with a tungsten
lamp (150 W) overnight. Volatiles were removed by a rotary evaporator,
and the resulting pale yellow, viscous liquid was chromatographed on
a column of silica gel (50 g, Acros, 0.035-0.07 mm) with hexane as
eluent. Removal of the solvent left a colorless liquid which was
crystallized from hexane to give 0.88 g of 11 as colorless solid: mp
1
3
from hexane and acetone. Mp: 131-133 °C. Yield: 0.16 g, 42%.
C
NMR (CDCl
3
): δ 124.0, 129.1, 131.0, 137.4, 138.5, and 140.1. IR
-1
+
(cm ): 1636, 1487, 1383, 1278, 1230, and 1145. MS (m/e): 400 (M ),
+
+
+
+
+
330 (C10Cl
108 (C
6
), 260 (C10Cl
4
), 225 (C10Cl
3
), 190 (C10Cl
2
), 120 (C10 ),
+), and 84 (C
+
). HRMS (m/e): 399.750 599 (found), 399.750 822
9
7
1
(theor.). UV-vis (cyclohexane, nm): λmax 244 (13 900), 301 (20 300),
330 (25 200), 360 (sh, 10 400), 586 (br, 594). Anal. Calcd for C Cl :
1
1
1
09-111 °C Yield: 70%. H NMR (CDCl
3
): δ 5.08 (s, 1H), 5.74 (s,
): δ 52.1, 79.0, 85.6, 85.8, 129.5, 131.3, 131.9,
36.9, 138.1, 139.1. UV (cyclohexane, nm): λmax 227 (12 800), 251
1
3
H). C NMR (CDCl
3
10
8
C, 29.75; H, 0.0; Cl, 70.25. Found: C, 30.25; H, 0.0; Cl, 69.85.
-1
1,2,3,4,5,6,7-Heptachloroazulene (13). Triene 11 (0.1356 g, 0.2842
mmol) was treated with the base 12 (90 µL, 0.290 mmol) in the same
manner as described above. After the reaction mixture was warmed to
about 0 °C, mercury (0.1 mL, 6.8 mmol) was added. The mixture was
stirred at room-temperature overnight. The deep blue solution was
isolated from the unreacted mercury by a pipet. After the solvent had
been removed by rotary evaporation, the residue was chromatographed
on a column of silica gel (50 g, Acros, 0.035-0.07 mm) with hexane as
eluent to give 0.05 g of 13 as a green solid: mp 148-150 °C. Yield:
(
15 400), 259 (15 100), 283 (9140). IR (KBr, cm ): 2960, 1563, 1511,
294, 1264, 1240, 1166, 1051, 877, 829, 696, 629 and 538. Anal. Calcd
for C10 Cl10: C, 25.20; H, 0.42; Cl, 74.38. Found: C, 25.27; H, 0.46;
Cl, 74.55.
X-ray Crystal Structure of 11.20 A colorless, block crystal (triclinic,
approximate dimensions 0.32 × 0.30 × 0.26 mm) of 11 (C10
1
H
2
2
H Cl10,
M.W. 476.62) was placed onto the tip of a 0.1 mm diameter glass
capillary and mounted on a CCD area detector diffractometer for a
data collection at 173(2) K. A preliminary set of cell constants was
calculated from reflections harvested from three sets of 20 frames. These
initial sets of frames were oriented such that orthogonal wedges of
reciprocal space were surveyed. This produced initial orientation
matrixes determined from 97 reflections. The data collection was carried
out using Mo KR radiation (graphite monochromator) with a frame
time of 10 s and a detector distance of 4.9 cm. A randomly oriented
region of reciprocal space was surveyed to the extent of a full sphere
and to a resolution of 0.84 Å. Three major sections of frames were
collected with 0.20° steps in ω at 3 different φ settings and a detector
position of -28° in 2θ. The intensity data were corrected for absorption
1
13
48%. H NMR (CDCl
3
): δ 8.42 (s, 1H). C NMR (CDCl ): δ 116.9,
3
119.3, 123.7, 129.7, 129.9, 132.6, 140.4, 141.1, and 142.7. MS m/e:
+
+ +
+
+
366 (M ), 296 (C10HCl ), 226 (C10HCl ), 156 (C10HCl ), 120 (C10 ).
5
3
UV/Vis (cyclohexane, nm): λmax 247 (13 000), 277 (24 500), 322
(44 200), 368 (4750), 386 (6050), 654 (366), and 704 (336). IR (KBr,
-
1
cm ): 1583, 1484, 1474, 1380, 1304, 1224, 1106, 910, 840, and 716.
Anal. Calcd for C10HCl : C, 32.50; H, 0.27; Cl, 67.22. Found: C,
32.62; H, 0.25; Cl, 67.47.
7
Pyrolysis of Triene 11. The triene (32 mg, 0.07 mmol) was placed
in an ampule which was evacuated and sealed under vacuum. It was
then heated at 250 °C for 1 h. The resulting pale yellow crystals were
washed with acetone until colorless. Recrystallization from hexane
afforded 10 mg of 1H-heptachloronaphthalene as white crystals (40%
2
1
and decay (SADABS). Final cell constants were calculated from the
xyz centroids of 3008 strong reflections from the actual data collection
after integration (SAINT 6.01, 1999).22 Unit cell dimensions were as
follows: a ) 5.8505(5) Å, b ) 8.3803(7) Å, c ) 17.609(2) Å; R )
8
yield). Mp 180-182 °C. (lit.26 183.5-184.5 °C; cf. mp of 2H-
1
2.391(2)°, â ) 80.494(2)°, γ ) 72.591(2)°, Z ) 2.
heptachloronaphthalene, 110.0-110.5 °C). H NMR (CDCl
3
): δ 8.45
23
(s, 1H); lit.26 (CDCl ) δ 8.73; cf δ for 2H-heptachloronaphthalene, 7.78).
C NMR (CDCl ): δ 135.8, 135.1, 134.3, 132.6, 131.3, 130.3, 129.8,
The structure was solved using SIR92 and refined using SHELXL-
3
7.24 The space group P-1 was determined based on intensity statistics.
13
9
3
+
+
A direct-methods solution was calculated which provided most non-
hydrogen atoms from the E-map. Full-matrix least squares/difference
Fourier cycles were performed which located the remaining non-
hydrogen atoms. All non-hydrogen atoms were refined with anisotropic
displacement parameters. All hydrogen atoms were placed in ideal
positions and refined as riding atoms with relative isotropic displacement
parameters. The final full matrix least squares refinement converged
129.3, 127.3, and 125.4. GC/MS (m/e): 366 (M ), 331 (C10HCl
6
),
). Octachloronaphtha-
lene was identified in the pyrolysis product by GC/MS, m/e: 400
+
+
+
296 (C10HCl
5
), 261 (C10HCl
4
), 226 (C10HCl
3
27
+
+ + +
+
(M ), 330 (C10Cl ), 260 (C10Cl ), 190 (C10Cl ), 120 (C10 ).
6 4 2
Acknowledgment. The authors are grateful to the National
Science Foundation for support of this work. We also thank
Neil R. Brooks, Victor G. Young, Jr., and the X-ray Crystal-
lographic Laboratory in the Department of Chemistry, University
of Minnesota for the X-ray crystal structure.
2
to R1 ) 0.0370 and wR2 ) 0.0930 (F , all data). Goodness-of-fit on
2
25
F ) 1.108. The program PLATON was used in checking for errors.
Octachloroazulene (3). Triene 11 (0.4480 g, 0.9392 mmol) was
dissolved with anhydrous THF (5 mL) in a 25 mL three-necked flask
fitted with a dropping funnel. When the system had been flushed with
Supporting Information Available: Tables of X-ray crystal-
lographic data for 11; X-ray crystallographic data (CIF). A table
of decachlorotetrahydroazulene energies (AM1) is also included.
This material is available free of charge via the Internet at
http://pubs.acs.org.
(
20) Data collection and structure solution were conducted at the X-ray
Crystallographic Laboratory, 160 Kolthoff Hall, Department of Chemistry,
University of Minnesota.
21) An empirical correction for absorption anisotropy, Blessing, R. Acta
Crystallogr. 1995, A51, 33-38.
(
(
22) SAINT V6.1; Bruker Analytical X-ray Systems: Madison, WI.
23) SIR92; Altomare, A.; Cascarno, G.; Giacovazzo, C.; Guargliardi, A. J. Appl.
Crystallogr. 1993, 26, 343-350.
(
JA012051H
(
24) SHELXTL-Plus V5.10; Bruker Analytical X-ray Systems: Madison, WI
1
998.
(26) Garci a´ , R.; Riera, J.; Carilla, J.; Juli a´ , L.; Molins, E.; Miravitlles, C. J.
(
25) Spek, A. L. Acta Crystallogr. 1990, A46, C34. Spek, A. L. PLATON, A
Multipurpose Crystallographic Tool; Utrecht University: Utrecht, The
Netherlands, 2000.
Org. Chem. 1992, 57, 5712.
(27) Jakobsson, E.; Eriksson, L.; Bergman, A° . Acta Chem. Scand. 1992, 46,
527.
J. AM. CHEM. SOC.
9
VOL. 124, NO. 51, 2002 15307