P. Guadarrama et al. / Journal of Molecular Structure 1086 (2015) 17–24
23
0
0
0
methylene chloride (freshly distilled before use), solvents and
reagents were used without further purification. NMR (CDCl
and FT-IR spectra were recorded in spectrometer Brucker Avance
b,b,-Bis(b ,b -dibromostyryl-4 ethynyl)-4-nitrostyrene (7). Red-
3
)
dish solid (m.p. 85–87 °C) in 45% yield.
1
H NMR (CDCl
3 2
): 8.25 (d, 2H, ortho to NO ), 8.07 (d, 2H, meta to
4
00 MHz, and FT-IR Nicolete Model PCIR, respectively.
The visible absorption and emission (excitation at 350 nm)
NO
2
dibromostyryl), 7.53 (s, 2H, HC@CBr ). FT-IR (cm ): 3056 (CAH
2
), 7.71 (dd, 4H, meta to dibromostyryl), 7.56 (dd, 4H, ortho to
ꢁ1
spectra were measured by Double Beam, UNICAM spectrometer
arom.), 2200 (C„C), 1600 (C@C arom.), 1484 (NO
2
), 1185 and
and Cary-Eclipse Varian fluorescence spectrometer respectively.
1120 (CAN), 696 (CABr).
4
0
0
0
Solutions of 1 ꢂ 10
l
g/L were prepared in three different solvents:
Bis[b,b-di(b ,b -dianilinephenylethynyl-4-styryl-4 -ethynyl)-4-
styryl] nitrostyrene (8). Reddish solid (m.p. 189–192 °C) in 30%
yield.
methylene chloride, ethyl acetate and chloroform, and measured in
the absorbance range of Lambert–Beer law.
1H NMR (CDCl
NO
): 8.35 (d, 2H, ortho to NO
), 7.95 (dd, 4H, ortho to 4 -ethynyl), 7.52 (dd, 4H, meta to 4 -
), 8.08 (d, 2H, meta to
3
2
0
0
⁄
2
Estimation of dipole moments in excited state (
methods
l
) by solvatochromic
ethynyl), 7.64 (m, 8H, meta to NH
2 2
), 7.49 (m, 8H, ortho to NH ),
7
.12 (s, 1H, HC@C), 7.13 (s, 1H, HC@C),7.00 (s, 1H, HC@C), 3.95
ꢁ
1
(
2
(NO
8H ,NH
2
). FT-IR (cm ): 3402 (NAH), overtones > 3402 (NAH),
865 (CAH), 2367 (C„C), 1643 (C@C arom.), 1452 (NO ), 1348
), 883, 834 (para-substitution).
The excited state dipole moments of synthesized molecules
2
were estimated by the solvatochromic method, according to Kou-
N
2
tek formulation [24], using the solvent parameter E
T
for methylene
0
0
0
Bis[b,b-di(b ,b -diformylphenylethynyl-4-styryl-4 -ethynyl)-4-
styryl] nitrostyrene (9). Reddish solid (m.p. 202–204 °C) in 30%
yield.
chloride and chloroform (0.309 and 0.259 respectively). Parame-
ters like dipole moments and Onsager radii in ground state,
involved in the mathematical model [25,26], were obtained from
theoretical calculations for the molecules under study. A detailed
description of the method can be found in Supporting information.
1H NMR (CDCl
NO
3
): 10.10 (4dd, 4H, HCO), 8.40 (d, 2H, ortho to
0
2
), 8.08 (dd, 2H, meta to NO
2
), 7.83 (dd, 4H, ortho to 4 -ethynyl),
0
7
.54 (dd, 4H, meta to 4 -ethynyl), 7.68 (m, 8H, meta to formyl), 7.48
ꢁ1
(
m, 8H, ortho to formyl), 7.00 (s, 3H, HC@C). FT-IR (cm ): 3020 (CH
arom.), 2200 (C„C), 1695 (C@O), 1590 (C@C), 1510 (NO arom.),
320 (NO ).
Computational details
2
1
2
Theoretical calculations were carried out using Gaussian 09
suite of programs [27]. The selected model was M05-2X [28] in
combination with the basis set cc-pVDZ [29]. The validation of
the method is described in Supporting information.
For each molecule under study, a structural optimization for the
ground state (S0) was carried out, and afterwards the optimized
structure was used for the calculation of the excitation (S1) by time
dependent density functional theory (TD-DFT) model.
Acknowledgements
We are grateful to PAPIIT IN-101512/24 and IB101712 for finan-
cial support. The authors wish to thanks A. Peña-Huerta and G.
Cedillo-Valverde for NMR study, and Joaquín Morales and Caín
González for technical support.
All the calculations (single points and structural optimizations
either in ground and excited states) were carried out in three dif-
ferent solvents: methylene chloride, chloroform and ethyl acetate,
using the PCM model [30] incorporated in Gaussian 09 suite of
programs.
Appendix A. Supplementary material
Synthesis
References
All synthetic details can be found in Supporting information;
here is shown the summary of spectroscopic characterization.
b,b-dibromo-4-nitrostyrene (2). Yellow solid (m.p. 50–52 °C) in
[
[
6
5% yield.
[
1
H NMR (CDCl
), 7.45 (HC@C). FT-IR (cm ): 3056 (CH arom.), 1590 (C@C
arom.), 1189 y 1120 (CAN), 696 (CABr), 1484 (NAO).
-ethynylbenzaldehyde (4). Yellow solid (m.p. 64–65 °C) in 80%
3
): 8.20 (d, 2H, ortho to NO
2
), 7.70 (d, 2H meta to
[
ꢁ1
NO
2
4
[
yield.
1H NMR (CDCl
3
): 3.30 (s, 1H HC„C), 7.80 (d, 2H arom.), 7.60 (d,
[
ꢁ1
2
H arom.), 10.02 (s, 1H, CHO). FT-IR (cm ): 2890 (CAH arom.),
2
150 (C„C), 1700 (C@O), 1600 (C@C arom.).
b,b-di(4 -aminophenylethynyl)-4-nitrostyrene (5). Dark orange
[
0
solid (m.p. 140–142 °C) in 51% yield.
1
[
[
[
H NMR (CDCl
), 7.5 (s, 1H, HC@C), 7.3 (d, 2H, meta to NH
3
): 8.2 (d, 2H, ortho to NO
2
), 7.6 (d, 2H, meta to
), 6.6 (d, 2H, ortho
). FT-IR (cm ): 2864 (CH), 3430 (NH), 2357–1946 (C@C),
600 (C@C arom.), 1454 (NAO).
NO
to NH
2
2
ꢁ
1
2
1
0
b,b-(4 formylphenylethynyl)-4-nitrostyrene (6). Brown–orange
solid (m.p. 150–152 °C) in 53% yield.
[
1
H NMR (CDCl
3 2
): 10.06 (s ,2H CHO), 8.28 (d, 2H, ortho to NO ),
7
.89 (d, 4H meta CO), 7.71 (d, 4H ortho to CO), 7.53 (s, 1H, HC@C);
[
ꢁ1
FT-IR (cm ): 3061 (CH arom.), 2920 (CH aliph.), 2207 (C„C), 1695
C@O), 1426 (NO ),1596 (C@C arom.)
(
2