A R T I C L E S
Andreu et al.
7
0 eV. Accurate mass measurements were obtained by narrow-range
of acetic acid and 0.56 mL of pyridine was refluxed under argon for
55 min. At the end of the reaction, the red solution was cooled to room
temperature and water (100 mL) and CH Cl (100 mL) were added.
2 2
voltaje scanning at 10 000 resolution (measured as peak width at 5%
height) using perfluorokerosene as reference compound and were
corrected to an accuracy of (10 ppm of the theoretical value. Electronic
spectra were recorded with a UV-vis-NIR Cary 500 Scan spectro-
photometer. Cyclic voltammetry measurements were performed with
a µ-Autolab ECO-Chemie potentiostat, using a glassy carbon working
electrode, Pt counter electrode, and Ag/AgCl reference electrode. The
experiments were carried out under argon, in CH
Bu
mV s
The organic layer was separated and washed successively with 5%
aqueous NaOH (2 × 100 mL) and water (2 × 100 mL). Then, it was
4
dried over MgSO , evaporated and purified by column chromatography
(silica gel) using CH
mg, 23%); mp 199-202 °C (lit. 192-195 °C); δ
s), 6.74 (1H, s), 1.30 (9H, s); δ (CDCl ) 184.82, 160.39, 144.34,
2 2
Cl as eluent, giving an orange-red solid (260
46
H
3
(CDCl ) 7.02 (1H,
2
Cl
2
or DMF, with
C
3
as supporting electrolyte (0.1 mol L- ). Scan rate was 100
1
126.54, 121.86, 117.72, 35.14, 29.47; ν(CO) 1603 cm- ; HRMS (EI):
1
4
NPF
6
-
1
+.
.
306.1127 (M ) Calcd. for C17
H
22OS
2
306.1112. Anal. Calcd. for C17
22
H -
EFISH Measurements. EFISH Measurements were taken with a
2
OS : C, 66.62; H, 7.24; S, 20.92. Found: C, 66.76; H, 7.11; S, 20.80.
nonlinear optics spectrometer from SOPRA. The fundamental light at
2-[4-(4,5-Bis-pentylsulfanyl-[1,3]dithiol-2-ylidene)cyclohexa-2,5-
dienylidene]-malononitrile (5a). A solution of 2-methylsulfanyl-4,5-
bis-pentylsulfanyl-[1,3]dithiolium tetrafluoroborate (316 mg, 0.72
mmol) and phenylmalononitrile (204 mg, 1.44 mmol) in a mixture of
acetic acid (0.8 mL) and pyridine (0.08 mL) was refluxed under Ar
for 45 min. After cooling, the blue mixture was filtered off and the
resulting solid was washed with water, then with EtOH and then with
1
.907 µm was the first Stokes peak of a hydrogen Raman cell pumped
by the 1.064 µm light from a Q-switched Nd:YAG laser (Quantel YG
81, 10 pps, 8 ns, pulse). That light was passed through a linear polarizer
7
and focused on the EFISH cell. The polarizing dc voltage (parallel to
the light polarization) used in this cell was 6 kV. The output light from
the cell was passed through an interference filter to select the second
harmonic light (0.954 µm) which was finally detected with a R642
photomultiplier from Hamamatsu. Static µâ(0) values were deduced
from the experimental values using a two-level dispersion model.
X-ray Single-Crystal Diffraction data were collected at 294 K on
a STOE-IPDS diffractometer equipped with a graphite monochromator
utilizing MoKR radiation (λ ) 0.71073 Å). The structure was solved
Et O to afford a first fraction (22 mg) of the desired compound. The
2
filtrate was evaporated under vacuum and the resulting residue was
dissolved in CH Cl ; the resulting solution was then successively
2
2
washed with water, 5% aq. NaOH and water, dried with Na
evaporated under reduced pressure. Purification was effected by column
chromatography on silica gel and elution with CH Cl gave 262 mg of
a blue-violet solid (total yield 89%); mp 198-200 °C; δ (CDCl ) 7.10
2 4
SO and
2
2
4
0
2
by direct methods using SIR92 and refined on F by full matrix least-
H
3
4
1
squares techniques using SHELXL-97 with anisotropic thermal
parameters for all non-hydrogen atoms. Absorption was corrected by
multiscan technique and the H atoms were included in the calculation
without refinement.
(1H, d, J ) 9.1 Hz), 7.03 (1H, d, J ) 9.1 Hz), 2.95 (2H, t, J ) 7.4
Hz), 1.68 (2H, q, J ) 7.0 Hz), 1.45-1.32 (4H, m), 0.92 (3H, t, J )
-
1
+.
7.0 Hz); ν(CN) 2195, 2166 cm ; HRMS (EI): 446.0983 (M ) Calcd.
for C22 446.0979. Anal. Calcd. for C22 : C, 59.15; H,
H N S
26 2 4
26 2 4
H N S
3
5.87; N, 6.27; S, 28.71. Found: C, 59.32; H, 5.70; N, 6.43; S, 28.52.
Crystal data for 5a: dark blue plate (0.63 × 0.47 × 0.08 mm ),
C
22
H N S
26 2 4
, Mr ) 446.69, triclinic, space group P-1, a ) 7.4716(8)
5-[4-(4,5-Bis-hexadecylsulfanyl-[1,3]dithiol-2-ylidene)cyclohexa-
2,5-dienylidene]-1,3-dimethylpyrimidine-2,4,6-trione (7). A solution
of 4,5-bis-hexadecylsulfanyl-2-methylsulfanyl-[1,3]dithiolium tetrafluo-
roborate (262 mg, 0.35 mmol) and 1,3-dimethyl-5-phenylbarbituric acid
(247 mg, 1.06 mmol) in a mixture of acetic acid (0.6 mL) and pyridine
(0.1 mL) was refluxed under Ar for 45 min. After cooling to room
temperature the resulting solid was filtered off, washed with water and
then with EtOH and dried to afford the desired compound as a blue-
Å, b ) 8.133(1) Å, c ) 20.356(2) Å, R ) 97.94(1)°, â ) 93.89(1)°,
3
-3
γ ) 104.08(1)°, V ) 1181.7(2) Å , Z ) 2, Fcalc ) 1.255 gcm , µ
(
-1
MoKR) ) 0.412 mm , F(000) ) 472, θmin ) 2.03°, θmax ) 25.76°,
1
1517 reflections collected, 4196 unique (Rint ) 0.0712), restraints/
parameters ) 3/253, R1 ) 0.0546 and wR2 ) 0.1298 using 1630
reflections with I >2σ(I), R1 ) 0.1379 and wR2 ) 0.1587 using all
-
3
data, GOF ) 0.821, -0.222 < ∆F < 0.174 e.Å
.
-
1
Computational Procedures. All theoretical calculations were
violet solid: 256 mg, 86%; mp 59-60 °C; ν(CO) 1678 cm ; MS
4
2
+
performed by using the Gaussian 03 program. The molecular
geometries were optimized without symmetry restrictions unless
(LSIMS): 845.5 (M+H ). Anal. Calcd. for C47
H
76
N O
2 3
4
S : C, 66.77;
H, 9.06; N, 3.31; S, 15.17. Found: C, 66.90; H, 9.19; N, 3.46; S, 15.02.
43
44
otherwise stated using the B3P86 functional and the 6-31G(d) basis
set. The same model chemistry was used in TD-DFT calculations and
the excited-state dipole moments were calculated by using the one
particle RhoCI density. Molecular hyperpolarizabilities at zero fre-
quency were calculated by the Coupled Perturbed Hartree-Fock
Method (PCHF) using the HF/6-31G(d) model chemistry and the default
parameters provided by the “polar” keyword. The default Gaussian
5-[4-(4,5-Bis-hexadecylsulfanyl-[1,3]dithiol-2-ylidene)cyclohexa-
2,5-dienylidene]-1,3-diethyl-2-thioxodihydropyrimidine-4,6-dione (8).
This compound was prepared from 4,5-bis-hexadecylsulfanyl-2-meth-
ylsulfanyl-[1,3]dithiolium tetrafluoroborate (142 mg, 0.19 mmol) and
1,3-diethyl-5-phenylthiobarbituric acid (160 mg, 0.58 mmol) in a
mixture of acetic acid (0.4 mL) and pyridine (0.056 mL), by using the
same conditions as described above for 7. After cooling, the dark blue
mixture was filtered and the solid was washed successively with water,
0
3 parameters were used in every case. Molecular orbital contours were
4
5
plotted using Molekel 4.3.
EtOH and Et O. The resulting solid was then treated with pentane to
2
2
,6-Di-tert-butyl-4-([1,3]dithiol-2-ylidene)cyclohexa-2,5-dienone
2). A solution of 2-methylsulfanyl-1,3-dithiolium iodide (1.035 g, 3.75
mmol) and 2,6-di-tert-butylphenol (2.317 g; 11.25 mmol) in 3.75 mL
remove the unreacted 1,3-diethyl-5-phenylthiobarbituric acid, which
was filtered off. After evaporation of pentane, the residue was purified
(
by gradient column chromatography on silicagel (CH
CH Cl /EtOAc 97:3), to afford a deep blue solid: 131 mg, 77%; mp
57 °C; δ (CDCl ) 8.83 (1H, d, J ) 9.1 Hz), 7.45 (1H, d, J ) 9.1 Hz),
.65 (2H, q, J ) 7.0 Hz), 3.05 (2H, t, J ) 7.3 Hz), 1.25 (31H, s), 0.88
2 2
Cl followed by
2
2
(
40) SIR92 - A program for crystal structure solution. Altomare, A.; Cascarano,
G.; Giacovazzo, C.; Guagliardi, A. J. Appl. Crystallogr. 1993, 26, 343-
H
3
4
3
50.
1
+.
(
41) SHELX97 [Includes SHELXS97, SHELXL97, CIFTAB (and SHELXA) ]
(3H, t, J ) 7.0 Hz); ν(CS) 1106 cm- ; MS (LSIMS): 888.5 (M ).
Anal. Calcd. for C49 : C, 66.16; H, 9.07; N, 3.15; S, 18.02.
Found: C, 66.01; H, 9.22; N, 3.31; S, 17.83.
-[4-(2-[1,3]Dithiol-2-ylidenethylidene)cyclohexa-2,5-dienylidene]-
-
Programs for Crystal Structure Analysis (Release 97-2). Sheldrick, G.
80 2 2 5
H N O S
M., Instit u¨ t f u¨ r Anorganische Chemie der Universit a¨ t, Tammanstrasse 4,
D-3400 G o¨ ttingen, Germany, 1998.
(
42) Gaussian 03, Revision B.05, Frisch, M. J. et al.; Gaussian, Inc., Pittsburgh,
PA, 2003.
43) The B3P86 Functional consists of Becke’s three parameter hybrid functional
2
malononitrile (10a). To a solution of [1,3]dithiol-2-ylideneacetaldehyde
(44 mg, 0.305 mmol) in acetic anhydride (1 mL), phenylmalononitrile
(
(
Becke, A. D. J. Chem. Phys. 1993, 98, 5648-5652) with the nonlocal
correlation provided by the Perdew 86 expression: Perdew, J. P. Phys.
ReV. B 1986, 33, 8822-8824.
(
(
44) Hariharan, P. C.; Pople, J. A. Theor. Chim. Acta 1973, 28, 213-222.
45) Portmann, S.; L u¨ thi, H. P. Chimia 2000, 54, 766-770.
(46) Schaumann, E.; Winter-Extra, S.; Kummert, K.; Scheiblich, S. Synthesis
1990, 271-273.
8844 J. AM. CHEM. SOC.
9
VOL. 127, NO. 24, 2005