Methyl and Dimethyl Derivatives of Tetrathionaphthalene and Tetraselenonaphthalene as Novel Electron Donors 291
ture was stirred for 80 hours at RT. After water (20
Na2Se2 reagent. After 1,4,5,8-tetrachloro-2-methyl-
naphthalene (2) (100 mg, 0.36 mmol) had been
added, the mixture was refluxed for 22 hours, ex-
posed to air overnight at RT, and then poured into
brine (70 mL). The resulting solid was collected by
filtration, dried, and washed with methanol and then
with a small amount of carbon disulfide. After sub-
limation at a temperature over 200ꢀC under a high
mL) was added, the insoluble silica gel was removed
by filtration and washed with dichloromethane, and
the filtrate was extracted with dichloromethane (30
mL). The washings and the extracts were combined,
washed with brine, and dried (MgSO4). After evap-
oration of the solvent, the residue was purified by
column chromatography on silica gel using hexane
as eluant, followed by recrystallization from 1:3 ben-
zene-methanol to give colorless needles of 5 (0.35 g,
vacuum ꢁ10 torr, recrystallization of the subli-
mate from 2:1 benzene-carbon disulfide gave a black
37%); MS m/z 292 (M based on 35Cl) with the iso-
powder of MTSN (85 mg, 52%): m.p. 228–229ꢀC; MS
topic pattern of four Cl atoms; 1H NMR d 2.48 (s, 6H,
CH3), 7.46 (s, 2H, ArH); Anal. Calcd for C12H8Cl4: C,
49.02; H, 2.74%. Found: C, 49.10; H, 2.62%.
m/z 458 (M based on 80Se) with the isotopic pattern
of four Se atoms; 1H NMR (CDCl3-CS2) d 2.18 (s, 3H,
CH3), 6.93 (s, 1H, ArH), 6.98 (d, J ס
7.7 Hz, 1H, ArH),
7.01 (d, J ס
7.7 Hz, 1H, ArH); Anal. Calcd for
C11H6Se4: C, 29.10; H, 1.33%. Found: C, 29.18; H,
1.30%.
3-Methylnaphtho[1,8-c,d:4,5-cЈdЈ]bis[1,2]
dithiole (MTTN) and 3,7-Dimethylnaphtho
[1,8-c,d:4,5-cЈdЈ]bis[1,2]dithiole (DMTTN)
DMTSN was similarly obtained in 41% yield
from 1,4,5,8-tetrachloro-2,6-dimethylnaphthalene
(5): black needles from 2:1 benzene-carbon disulfide;
A mixture of sulfur powder (137 mg, 4.3 mmol) and
sodium methylate (231 mg, 4.3 mmol) in DMA (7
mL) was heated in an oil bath, the temperature ris-
ing from 100ꢀC to 150ꢀC over a period of 30 minutes,
and then maintained at 120ꢀC for 6 hours. After
1,4,5,8-tetrachloro-2-methylnaphthalene (2) (100
mg, 0.36 mmol) had been added, the mixture was
heated for an additional 17 hours at 120ꢀC, exposed
to air overnight at RT, and then poured into brine
(40 mL). The resulting solid was collected by filtra-
tion, dried, and purified by column chromatography
on silica gel using carbon disulfide as eluant, fol-
lowed by sublimation at a temperature over 200ꢀC
m.p. 296–297ꢀC; MS m/z 472 (M based on 80Se) with
the isotopic pattern of four Se atoms; 1H NMR
(CDCl3-CS2) d 2.18 (s, 6H, CH3), 6.91 (s, 2H, ArH);
Anal. Calcd for C12H8Se4: C, 30.78; H, 1.72%. Found:
C, 30.80; H, 1.65%.
Preparation of Charge-Transfer Complexes
The hot saturated solution of the donor component
in chloroform was mixed with that of an equimolar
amount of TCNQ in chloroform, and, after cooling,
the resulting solid of charge-transfer complex was
collected by filtration and thoroughly washed with
cold dichloromethane.
Anal. of MTTN•TCNQ complex, Found: C,
58.58; H, 2.17; N, 10.64% (Calcd. for 1.2:1 stoichi-
ometry: C, 55.75; H, 2.26; N, 11.21%).
DMTTN•TCNQ, Found: C, 59.32; H, 2.61; N, 11.51%
(Calcd. for 1:1 stoichiometry: C, 59.48; H, 2.50; N,
11.56%). MTSN•TCNQ, Found: C, 42.54; H, 1.51; N,
8.99% (Calcd. for 1:1 stoichiometry: C, 42.83; H,
1.54; N, 9.08%). DMTSN•TCNQ, Found: C, 42.88; H,
1.86; N, 8.35% (Calcd. for 1:1 stoichiometry: C,
42.88; H, 1.80; N, 8.33%).
under a high vacuum ꢁ10 torr. Recrystallization
of the sublimate from 1:1 benzene-methanol gave a
yellowish brown powder of MTTN (10 mg, 10%):
m.p. 146–147ꢀC; MS m/z 266 (M ); 1H NMR (CDCl3-
CS2) d 2.15 (s, 3H, CH3), 6.69 (s, 1H, ArH), 6.76 (d, J
ס
7.8 Hz, ArH), 6.78 (d, J ס
7.8 Hz, ArH); Anal.
Calcd for C11H6S4: C, 49.59; H, 2.27%. Found: C,
49.58; H, 2.24%.
DMTTN was similarly obtained in 23% yield
from 1,4,5,8-tetrachloro-2,6-dimethylnaphthalene
(5): reddish brown needles from 1:1 benzene-meth-
1
anol; m.p. 136–137ꢀC; MS m/z 280 (M ); H NMR
(CDCl3-CS2) d 2.15 (s, 6H, CH3), 6.70 (s, 2H, ArH);
Anal. Calcd for C12H8S4: C, 51.40; H, 2.88%. Found:
C, 51.36; H, 2.83%.
X-Ray Crystallographic Analyses of DMTSN
3-Methylnaphtho[1,8-c,d:4,5-cЈdЈ]bis[1,2]
diselenole (MTSN) and 3,7-Dimethylnaphtho
[1,8-c,d:4,5-cЈdЈ]bis[1,2]diselenole (DMTSN)
The X-ray diffraction experiment was performed at
RT on a Rigaku AFC6S diffractometer with graphite-
monochromated Cu K␣ radiation (k ס
1.5418 A).
˚
The intensity data were measured using the x-2h
scan technique. The structure was solved by direct
methods and refined by full-matrix least-squares
A mixture of red selenium powder (203 mg, 2.57
mmol) and sodium (59.2 mg, 2.57 mmol) in DMF (8
mL) was heated at 120ꢀC for 5 hours to generate the