High nonlinear optical response in 4-chlorothiazole-based azo dyes

Article abstract of DOI:10.1016/j.dyepig.2010.07.011

Four azo dyes showing high nonlinear optical properties were prepared, based on a 4-chlorothiazole azo moiety functionalized with strong acceptor groups and/or further donor/acceptor groups along the conjugated backbone. The effects of the acceptors as we

Full text of DOI:10.1016/j.dyepig.2010.07.011

Dyes and Pigments 88 (2011) 290e295
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Dyes and Pigments
journal homepage: www.elsevier.com/locate/dyepig
High nonlinear optical response in 4-chlorothiazole-based azo dyes
,
a
a
a
a
b
Fabio Borbone a , Antonio Carella , Laura Ricciotti , Angela Tuzi , Antonio Roviello , Alberto Barsella
*
a Dipartimento di Chimica “Paolo Corradini”, Università degli Studi di Napoli Federico II, Complesso Universitario Monte Sant’Angelo, Via Cintia 80126, Napoli, Italy
b IPCMS-CNRS, GONLO, 23 Rue du Loess, 67037 Strasbourg Cedex, France
a r t i c l e i n f o
a b s t r a c t
Article history:
Four azo dyes showing high nonlinear optical properties were prepared, based on a 4-chlorothiazole azo
moiety functionalized with strong acceptor groups and/or further donor/acceptor groups along the
conjugated backbone. The effects of the acceptors as well as the lateral donor/acceptor groups upon
absorption properties, thermal stability and second order nonlinear optical activity were evaluated.
Ó 2010 Elsevier Ltd. All rights reserved.
Received 4 May 2010
Received in revised form
20 July 2010
Accepted 23 July 2010
Available online 5 August 2010
Keywords:
NLO chromophore
Azo dye
Donor/acceptor
Chlorothiazole
Bathochromism
1. Introduction
a conjugated bridge that allows a charge transfer of p-electrons.
Both the strength of the electron donor and acceptor groups and
the nature of the conjugated bridge are important parameters in
defining the activity of the chromophore. In this context, the old
established experience gained by the dyeing chemists represented
a huge database from which taking inspiration for new molecular
structures useful for NLO applications. For instance, derivatives of
indandione (like bis-dicyanovinyl derivative or the Sandoz group)
represent a class of very effective electron-withdrawing groups and
have been widely employed in pushepull dyes to tune the
absorption of the dyes toward the near IR zone of the spectrum
[15,16]; more recently NLO chromophores containing as electron-
acceptor group this class of indandione derivatives have proved to
be extremely efficient [17,18].
For what concerns the conjugated bridge, it is well known that
the use of heteroaromatic rings greatly enhances the molecular
hyperpolarizability of the dye because the lower resonance energy
of these rings, as compared with benzene, favours the charge
transfer (process in which the bridge itself turns from aromatic to
quinoid form) [19]. Particularly, very good results can be obtained
by using five membered heterocycles as thiophene and thiazole, as
proved both by theoretical [19e21] and experimental works
[22,23]. Also the position of these heterocycles along the bridge
plays an important role and being the just mentioned thiophene
and thiazole electron poor rings, their direct linking to the electron
acceptor group has a further beneficial effect on the NLO activity,
because the hetero-aromatic rings behave as auxiliary acceptors
[19e21].
Organic materials for application in second order nonlinear
optics (NLO) have drawn considerable interest in the last two
decades both from academic and industrial world, with the results
published in a wide number of reviews [1e5]. The origin of this
interest stems from the potentially higher activity achievable with
this class of materials as compared to the traditional inorganic ones,
from the ease of processing and integration with the well estab-
lished semiconductor technology and from the possibility of
addressing materials features, specific for the field of application,
by designing a proper synthetic strategy.
Second order NLO organic materials are typically based on NLO
chromophores that can be incorporated in polymer [6e10] or
hybrid organiceinorganic matrix [11,12] or in crosslinked system
[13]. The dendritic approach, in which the chromophore is func-
tionalized with branched bulky groups to hinder its tendency to
crystallize, has also been largely employed in the recent years [14].
In all these approaches the choice of the proper chromophore
plays a fundamental role: high NLO activity, expressed as the value
of first order molecular hyperpolarizability b, along with a fair good
photo- and thermal stability and a good solubility are required.
Typically, second order NLO chromophores are constituted by an
electron acceptor moiety linked to an electron donor group through
* Corresponding author. Tel.: þ39 081 674446; fax þ39 081 674367.
E-mail address: fabio.borbone@unina.it (F. Borbone).
0143-7208/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.dyepig.2010.07.011

F. Borbone et al. / Dyes and Pigments 88 (2011) 290e295
291
Driven by the above considerations, we report here on the
synthesis and NLO characterization of four chromophores, whose
molecular structure is reported in Fig. 1, containing as electron
acceptor group an indandione derivative (1, 2 or 3, see Fig. 1).
Chromophores c, e and f are molecules already described in
previous papers (at least for what concerns the conjugated core)
and characterized only with regard to their linear optical properties
while they have not been investigated yet for what concerns their
NLO properties; chromophore d is instead a totally new structure.
All the chromophores are diazo compounds and share the common
feature of having a thiazole ring directly linked to the electron
acceptor group; previous works have shown that the ability of the
thiazole ring to act as an auxiliary acceptor is also related to the
electron density on the carbon atom of the ring directly linked to
the acceptor (the lower the electron density the higher the acceptor
properties of the thiazole) [21]. We reckon therefore that the
presence of an electronegative chlorine atom on 4-position of
thiazole ring should enhance his ability to act as auxiliary acceptor
by reducing electron density on carbon in position 5.
and two CHCl3 solvent molecules in the asymmetric unit. Each
chloroform molecule is involved in weak hydrogen bonding inter-
actions both with A and B molecule and a dimeric Ci symmetric
adduct is formed. The two molecules A and B are geometrically
similar, only one of them is reported in the figure and discussed. All
bond lengths and angles were normal and in agreement with
similar compounds [26e28]. In the molecule, the methine H atom
is trans both to S atom of thiazole ring and to S atom of sulfone
group. The dicyanomethylene group is slightly rotated (C19-C20-
C27-C29 ¼ 173.7(9)ꢁ and 176.6(9)ꢁ for molecule A and B respec-
tively). The molecule is characterized by a quite overall planarity
and by a bent shape. The overall planarity is in keep with the
extension of conjugation along the whole molecule. The bent shape
is a consequence of the anti disposition of methine and azo groups
linked to thiazole. One of the ester tails linked to aminic N atom is
roughly in plane with the molecule, being stabilized in this
conformation by an intramolecular weak CeH/O interaction
(C14eH/O1 3.48(1)Å, 170.5(7)ꢁ and 3.52(2)Å, 173.8(7)ꢁ for mole-
cule A and B respectively). The other ester tail is pendant. In the
crystal packing the molecules are arranged in a parallel way
through weak CeH/N and CeH/O interactions (C11AeH/N6A(i)
3.32(1)Å, 123ꢁ; C7AeH/O3B(ii) 3.38(2)Å, 131ꢁ; C24BeH/N4A(iii)
3.30(1)Å, 133ꢁ; C23AeH/N4B(iv) 3.38(1)Å, 126ꢁ; C5BeH/O1B(v)
3.43(2) Å, 164ꢁ; C8BeH/O3A(vi) 3.41(1) Å, 157ꢁ; (i) ꢀx, ꢀy þ 1,
ꢀz þ 1; (ii) x þ 1, y ꢀ 1, z ꢀ 1; (iii) ex þ 1, ꢀy þ 1, ꢀz þ 1; (iv) ꢀx,
ꢀy þ 1, ꢀz þ 2; (v) ꢀx, ꢀy þ 2, ꢀz þ 2; (vi) x ꢀ 1, y þ 1, z þ 1). Sheets
Chromophores have been characterized for what concerns their
spectral and structural properties; their NLO activity have been
measured by means of EFISH techniques and the results will be
discussed in the next section.
2. Results and discussion
of molecules spaced by the pendant tails are formed. A
pep
The precursors azo compounds a (R]R0]H) and b (R ¼
NHCOCH3 and R0 ¼ OCH3) were synthesized by diazotation of
2-amino-4-chloro-5-formylthiazole with nitrosylsulfuric acid and
copulation on respectively N-phenyldiethanolamine and N-{3-[bis
(2-hydroxyethyl)amino]-4-methoxyphenyl}acetamide (Fig. 2).
Chromophores c, d and e were synthesized by condensation of
precursor a with respectively acceptors 1, 2, 3 and subsequent
acetylation; in the case of chromophore d the acetylation was
simultaneous to the condensation. Chromophore f was obtained by
condensation of compound b with electron-acceptor group 3 and
following acetylation.
For chromophore e it was possible to obtain single crystals
suitable for X-ray diffraction (by slow evaporation of CHCl3/heptane
solution) and its molecular structure has been solved and pre-
sented in Fig. 3. Compound crystallizes in P ꢀ 1 space group with
two crystallographically independent molecules (denoted A and B)
stacking of aromatic groups is observed (Fig. 4) between the sheets
with interlayer distance of about 3.4 Å. The chloroform molecules
are involved in weak CeH/O interactions with sulfone oxygen
atoms and are located in channels parallel to [1 0 0] crystallo-
graphic direction (C1eH/O6A 3.34(1) Å 139ꢁ; C1eH/O5B 3.21(1)
Å 130ꢁ; C2eH/O5A 3.11(1) Å 130ꢁ; C2eH/O6B 3.47(1) Å 126ꢁ).
As also reported in the literature [16,29] and for similar chro-
mophores these dyes show a strong bathochromic effect on the
absorption depending on the strength of their electron acceptor
groups. The dye d shows a 37 nm red shift of the absorption
maximum in chloroform (Fig. 5, Table 1) with respect to the dye c
due to the stronger electron withdrawing effect of two dicyano-
methylene groups. A similar absorption spectrum is observed for
the dye e bearing the moiety 3, known in the literature as Sandoz
group and as one of the strongest electron acceptor groups. The dye
f has the highest red shift compared with the dye c, 129 nm,
revealing that the NHCOCH3 and OCH3 groups on the phenyl ring
give a great contribution to the bathochromic shift of chromophore
f, whose absorption maximum is notably higher than that of the
same chromophore without these groups (e).
The thermal stability of the dyes was studied by means of
thermogravimetric analysis (Fig. 6) and the decomposition
temperatures are reported in Table 1. As shown the dyes stabilities
are quite similar and no significant effects of acceptor groups can be
observed.
The mb coefficients were measured by Electric Field Induced
Second Harmonic Generation (EFISH) technique. The measure-
ments were performed in chloroform solution at a wavelength of
1905 nm where the second harmonic (952.5 nm) is out the
absorption region of the chromophores. The results are listed in
Table 1 and reveal that the dye c has the lowest NLO coefficient, as
expected being the acceptor 1 an indandione functionalized with
a single dicyanomethylene group.
Indeed the addition of a second dicyanomethylene group (dye d)
favours a strong increase in the molecular second order NLO
response, which is more than doubled in the value of mb coefficient.
The acceptor 3 turns out again to have the largest effect also on the
nonlinear properties since the dye e has the highest mb coefficient
Fig. 1. Schematic representation of dyes structures.

292
F. Borbone et al. / Dyes and Pigments 88 (2011) 290e295
Fig. 2. Scheme for the synthesis of dyes. i: 1) H2SO4/NOHSO4, 2) H20/H2SO4; ii: EtOH, reflux, 4 h; iii: dioxane/Ac2O, reflux, 4 h; iv: Ac2O, 70 ꢁC, 4 h.
(5400$10ꢀ48 esu) of the series based on the azo compound b,
revealing a strong contribution of the SO2 moiety. Finally the dye f
as well shows a large nonlinear coefficient but in this case the
acetamido and methoxy groups have a detrimental effect on the
NLO response causing a decrease of mb compared to the dye e. These
results confirm that these type of chlorothiazole-based azo dyes,
already known for their linear absorption properties, also show
a strong nonlinear optical response. This feature can be exploited
for the synthesis of highly active NLO polymers, for example by
using the easily achievable di-hydroxylated form of the dyes, aimed
at the fabrication of efficient electro-optic devices.
on the absorption depending on the nature of their electron
acceptor groups, being notably higher in the case of the chromo-
phore functionalized with the 3-dicyanomethylene-2,3-dihy-
drobenzo[b]thiophene-1,1-dioxide and the methoxy and acetamido
side groups. All the chromophores have a good thermal stability in
air and show growing mb coefficients when the acceptor moiety is
varied from 3-(dicyanomethylene)-1-indanone to 1,3-bis(dicyano-
methylidene)indane and 3-dicyanomethylene-2,3-dihydrobenzo
[b]thiophene-1,1-dioxide. In this last case a decrease of the coeffi-
cient is observed if methoxy and acetamido side groups are present
on the phenyl ring.
3. Conclusions
4. Experimental
Four NLO chromophores based on a 4-chlorothiazole azo moiety
were synthesized. The chromophores were functionalized with
indandione derivatives as strong terminal acceptor groups and with
lateral methoxy and acetamido groups along the conjugated
backbone. The chromophores show a strong bathochromic effect
All solvents and reagents were purchased by Aldrich and used
without further purification. The thermal stability of the
compounds was studied by thermogravimetric analysis (TA SDT
2960, air, 10 K/min). 1H NMR and 13C NMR spectra were recorded
with a Varian XL 200-MHz apparatus. UV/Vis absorption spectra
Fig. 3. Ortep view of e with ellipsoids drawn at 30% probability level. Molecule B and CHCl3 solvent molecules are not shown for clarity. N2eN3 1.28 (1), 1.28(1)Å; N2eC12 1.39(1),
1.39(1)Å; N3eC15 1.37(1), 1.36(1)Å; N4eC15 1.33(1), 1.31(1)Å; N4eC16 1.35(1), 1.36(1)Å; S1eC15 1.728(9), 1.745(9)Å; S1eC17 1.755(9), 1.730(9)Å; S2eC19 1.770(9), 1.756(9)Å;
S2eC26 1.747(8), 1.747(9)Å; C18eC19 1.37(1), 1.34(1)Å; C19eC20 1.48(1), 1.47(1)Å; C21eC26 1.37(1), 1.36(1)Å; C20eC27 1.36(1), 1.37(1)Å.

F. Borbone et al. / Dyes and Pigments 88 (2011) 290e295
293
Fig. 4. A) Crystal packing of e viewed along (1 0 0) direction, only H atoms in CHCl3 molecules are reported for clarity. B) Crystal packing viewed along (0 1 ꢀ1) direction, showing
the sheets of co-planar molecules and the interlayer aromatic stacking.
pep
were recorded with a Jasco V560 spectrophotometer in chloroform
solutions. FT-IR spectra were recorded with a Jasco FT/IR-430
spectrophotometer on KBr pellets. Single crystals of dye e suitable
for X-ray diffraction were obtained by slow evaporation of CHCl3/
heptane solution. One crystal (dark green 0.55 ꢂ 0.50 ꢂ 0.15 mm)
was mounted at 173 K under N2 flow on a Bruker-Nonius KappaCCD
diffractometer equipped with a graphite monochromated MoKa
4.1. Syntheses
4.1.1. Synthesis of 2-((4-(bis(2-hydroxyethyl)amino)phenyl)
diazenyl)-4-chlorothiazole-5-carbaldehyde (a)
2-amino-4-chloro-5-formylthiazole (2.00 g, 12.3 mmol) was
dissolved in 5 mL H2SO4 and 2.5 mL nitrosylsulfuric acid 40% wt.
solution were added at 0e5 ꢁC under stirring. After 1 h the solution
was added to 2.23 g (12.3 mmol) N,N-dihydroxyethylaniline in
120 mL of water containing 1 mL H2SO4. After 4 h the product was
filtered and washed with water. Yield: 44%.
radiation (
l
¼ 0.71073 Å, CCD rotation images, thick slices,
4 and u
scans to fill asymmetric unit). Semi-empirical absorption correction
(SADABS) was applied. The structure was solved by direct methods
(SIR97 package [24]) and refined by the full matrix least-squares
method on F2 against all independent measured reflections
(SHELXL program of SHELX97 package [25]). All non-hydrogen
atoms were refined anisotropically. The hydrogen atoms were
introduced in calculated positions and refined according to a riding
1H NMR (DMSO; 300 MHz)
d: 3.98 (m, 8H), 5.11 (s, 2H), 7.22 (d,
2H, J ¼ 9.0 Hz), 7.98 (d, 2H, J ¼ 9.0 Hz), 10.07 (s, 1H).
4.1.2. Synthesis of N-(5-(bis (2-hydroxyethyl) amino)-2-
((4echloroe5eformylthiazole2-yl) diazenyl)-4-methoxyphenyl)
acetamide (b)
model. The final refinement converged to R1
¼
0.0959,
wR2 ¼ 0.2047. Crystals were poor quality and weakly diffracting.
This may explain the high R values obtained. Some constrains on
CeC bond lengths in one ester tail were introduced in the last stage
of refinement. Crystal data and refinement details are summarized
in Table 2. CCDC 771330 contains the supplementary crystallo-
graphic data for this paper. These data can be obtained free of
charge at www.ccdc.cam.ac.uk/conts/retrieving.html or from the
Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge
CB2 1EZ, UK; fax: (internat.) þ44-1223/336-033.
2-amino-4-chloro-5-formylthiazole (2.00 g, 12.3 mmol) was
dissolved in 3 mL H2SO4 and 2.5 mL nitrosylsulfuric acid 40% wt.
solution were added at 0e5 ꢁC under stirring. After 1 h the solution
was added to 3.30 g (12.3 mmol) N-{3-[bis(2-hydroxyethyl)amino]-
4-methoxyphenyl}acetamide in 100 mL of water containing 0.5 mL
H2SO4. After 4 h the solution was neutralized with potassium
hydroxide and saturated with sodium chloride. The product was
filtered, washed with water and then with hot ethanol. Yield: 55%.
1H NMR (DMSO; 300 MHz)
d: 3.84 (m, 3H), 3.89 (m, 8H), 5.00 (s,
2H), 7.36 (s, 1H), 8.05 (s, 1H), 9.95 (s, 1H), 10.0 (s, 1H).
4.1.3. Synthesis of dyes c, e, f, d
Dye c: 3-(Dicyanomethylene)-1-indanone (0.761 g, 3.92 mmol)
and compound a (1.39 g, 3.92 mmol) were dissolved in 80 mL
ethanol at reflux for 4 h. The product was filtered and washed with
ethanol. 0.500 g of the product were dissolved in 15 mL dioxane
Table 1
Linear and nonlinear optical properties and decomposition temperatures of dyes.
Dye
mb (10ꢀ48 esu)
lmax (nm)
Td (ꢁC)
c
d
e
f
2150
5200
5400
4600
643
680
676
772
248
232
230
230
Fig. 5. UVeVis spectra of the dyes in chloroform.

294
F. Borbone et al. / Dyes and Pigments 88 (2011) 290e295
IR (KBr) nmax: 2927 (w), 2215 (w), 1752 (m), 1733 (m), 1599 (m),
1582 (m), 1557 (m), 1520 (m), 1409 (w), 1312 (w), 1243 (m), 1210
(m), 1125 (s), 1098 (s), 873 (w), 831 (w), 765 (w), 728 (w), 643 (w).
HRMS calcd for C29H23ClN6O6S2: 650.08. Found: 650.60. Calcd for
C29H23ClN6O6S2: C, 53.49; H, 3.56; N,12.91. Found: C, 53.55; H, 3.98;
N, 12.66.
Dye f: 1H NMR (CDCl3; 200 MHz)
d: 2.08 (s, 6H); 2.34 (s, 3H);
3.89 (s, 3H); 3.99 (t, 4H, J ¼ 5.4 Hz); 4.39 (t, 4H, J ¼ 5.4 Hz); 7.37
(s, 1H); 7.87 (m, 2H); 7.95 (m, 1H); 8.22 (s, 1H); 8.83 (d, 1H,
J ¼ 7.7 Hz); 9.07 (s, 1H); 9.17 (s, 1H). 13C NMR (THF-d8; 200 MHz)
d:
21.47, 22.33, 31.74, 36.05, 56.30, 57.32, 59.54, 61.86, 63.94, 105.75,
119.13, 123.59, 123.95, 126.86, 127.35, 127.60, 129.84, 131.10, 131.53,
133.67, 136.25, 136.91, 137.54, 139.13, 141.09, 153.64, 169.81, 171.48.
IR (KBr) nmax: 2946 (w), 2210 (w), 1739 (m), 1698 (m), 1605 (m),
1582 (m), 1549 (m), 1505 (s), 1463 (m), 1438 (m), 1374 (m), 1238
(m), 1198 (m), 1172 (s), 1136 (s), 1096 (s), 1043 (s), 951 (w), 922 (w),
660 (w). HRMS calcd for C32H28ClN7O8S2: 737.11. Found: 737.62.
Calcd for C32H28ClN7O8S2: C, 52.07; H, 3.82; N, 13.28. Found: C,
52.22; H, 4.03; N, 13.31.
Fig. 6. Thermogravimetric analysis of the dyes.
containing 4 mL acetic anhydride at reflux for 4 h. The acetylated
chromophore was precipitated in 100 mL hexane and purified by
chromatography. Yield: 72%.
Dye d: 1,3-Bis(dicyanomethylidene)indane (0.683 g, 2.82 mmol)
and compound a (1.00 g, 2.82 mmol) were stirred in 12 mL acetic
anydride at 70 ꢁC for 4 h. The product was precipitated in 200 mL
hexane and purified by chromatography. Yield: 43%.
1H NMR (CDCl3; 200 MHz)
d
: 2.07 (s, 6H); 3.82 (t, 4H, J ¼ 5.8 Hz);
4.35 (t, 4H, J ¼ 5.8 Hz); 6.90 (d, 2H, J ¼ 8.8 Hz); 7.78 (m, 2H); 7.95
(d, 1H, J ¼ 7.4 Hz); 8.00 (d, 2H, J ¼ 8.8 Hz); 8.70 (d, 1H, J ¼ 5.8 Hz);
8.97 (d, 1H, J ¼ 28.8 Hz). 13C NMR (CDCl3; 200 MHz)
d: 20.80, 30.55,
1H NMR (CDCl3; 300 MHz)
d
: 2.04 (s, 6H); 3.82 (t, 4H, J ¼ 6.0 Hz);
50.16, 61.07, 112.63, 112.79, 124.35, 125.08, 125.62, 125.73, 128.72,
128.82, 133.55, 134.89, 135.86, 137.28,140.39, 140.79,144.93,153.95,
170.69, 182.27, 188.40. IR (KBr) nmax: 2929 (w), 2219 (w), 1735 (m),
1700 (w), 1599 (m), 1542 (m), 1466 (w), 1240 (m), 1216 (m), 1198
(m), 1115 (s), 1050 (m), 1020 (w), 990 (w), 875 (w), 833 (w), 723 (w).
HRMS calcd for C30H23ClN6O5S: 614.11. Found: 614.71. Calcd for
C30H23ClN6O5S: C, 58.58; H, 3.77; N, 13.66. Found: C, 58.63; H, 4.12;
N, 13.42.
4.33 (t, 4H, J ¼ 6.0 Hz); 6.89 (d, 2H, J ¼ 9.0 Hz); 7.79 (d, 2H,
J ¼ 4.2 Hz); 7.99 (d, 2H, J ¼ 9.0 Hz); 8.55 (m, 2H); 8.69 (s, 1H). 13C
NMR (CDCl3; 200 MHz) d: 20.84, 50.20, 61.02, 77.35, 112.93, 113.03,
125.15, 126.00, 126.08, 129.42, 129.56, 131.19, 131.83, 135.16, 144.84,
152.70, 154.59, 170.72, 179.81. IR (KBr) nmax: 2950 (w), 2220 (w),
1746 (m),1595 (m),1552 (m),1463 (m),1244 (m),1225 (m),1132 (s),
1051 (m), 872 (w), 835 (w), 718 (w). HRMS calcd for C33H23ClN8O4S:
662.13. Found: 662.64. Calcd for C33H23ClN8O4S: C, 59.77; H, 3.50;
N, 16.90. Found: C, 59.64; H, 3.76; N, 16.62.
The same procedure was applied for the synthesis of chromo-
phores e and f by using suitable amounts of compounds a and
b respectively.
Dye e: 1H NMR (CDCl3; 200 MHz)
d: 2.06 (s, 6H); 3.83 (t, 4H,
Acknowledgement
J ¼ 5.8 Hz); 4.34 (t, 4H, J ¼ 5.8 Hz); 6.91 (d, 2H, J ¼ 9.0 Hz); 7.88 (m,
3H); 7.99 (m, 2H); 8.85 (d, 1H, J ¼ 7.6 Hz); 9.10 (s, 1H). 13C NMR
Thanks are due to Centro Interdipartimentale di Metodologie
Chimico Fisiche (CIMCF) of University of Naples Federico II for X-ray
and NMR facilities.
(CDCl3; 200 MHz) d: 20.97, 50.19, 61.07, 73.97, 113.00, 113.99, 114.29,
122.47, 122.95, 126.12, 128.82, 129.09, 131.18, 135.06, 135.73, 138.87,
144.76, 151.16, 154.12, 154.55, 170.88, 182.96.
References
Table 2
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Adv Phys Org Chem. 1999;32:121e217.
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Empirical formula
Formula weight
Temperature
Wavelength
Crystal system
Space group
C29H23ClN6O6S2/CHCl3
770.47
173(2) K
0.71073 Å
Triclinic
P ꢀ 1
Unit cell dimensions
a ¼ 10.028(2) Å
b ¼ 15.513(2) Å
c ¼ 23.183(7) Å
a
b
g
¼ 102.49(2)ꢁ
¼ 91.62(2)ꢁ
¼ 104.84(1)ꢁ
[7] Kang JW, Kim TD, Luo J, Haller M, Jen AK. Very large electro-optic coefficient
from in situ generated side-chain nonlinear optical polymers. Appl Phys Lett.
2005;87(071109):1e3.
Volume
Z
Calculated density
Absorption coefficient
F(000)
3390(1) Å3
4
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q
range for data collection
Reflections collected/unique
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2
R indices (all data)
55296/11803 [R(int) ¼ 0.2854]
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