Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807041360/cv2287sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807041360/cv2287Isup2.hkl |
CCDC reference: 663665
Key indicators
- Single-crystal X-ray study
- T = 220 K
- Mean (C-C) = 0.004 Å
- R factor = 0.052
- wR factor = 0.150
- Data-to-parameter ratio = 16.6
checkCIF/PLATON results
No syntax errors found
Alert level B PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low ....... 0.95
Author Response: ...With regard to the missing completeness of the reflection data: The structure was measured on a newly installed (July 2006) Bruker X8 Proteum four circle diffractometer with a fine-focused rotating anode source with Cu radiation. This diffractometer is equipped with a sample changing robot, which limits access of the detector at high positive theta-angles. The beam stop support limits access at high negative theta-angles. The reported completeness and two theta values are the maximum values obtainable with the instrument, already optimized by using a data collection strategy employing two different crystal detector distances and the collection of ALL accessible data. |
Alert level C PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ? PLAT223_ALERT_4_C Large Solvent/Anion H Ueq(max)/Ueq(min) ... 3.48 Ratio
Author Response: ... There is a lot of libration in the triethylammonium counter-ion and introducing disorder did not seem to fix that problem. |
PLAT244_ALERT_4_C Low 'Solvent' Ueq as Compared to Neighbors for N2
Author Response: ... Ueq of N2 is low compared to those of terminal CH3 cause of the libration of the chain. |
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor .... 2.17
Author Response: ... The teminal CH3 as libration in the direction perpendicular to the bond and it is normal that this error occurs. |
0 ALERT level A = In general: serious problem 1 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 1 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
4,4'-Diamino-2,2'-stilbene-disulfonic acid from Aldrich was purified by successive acid and base washes. The starting material was then dissolved in an aqueous solution of triethylamine. The desired product was precipitated from cold ethanol and then crystallized from ethyl acetate.
H atoms were placed in calculated positions (C—H 0.93–0.97 Å, N—H 0.87–0.92 Å) and they were included in the riding-model refinement approximation, with Uiso(H) = 1.2–1.5 Ueq of the parent atom.
Stilbenes such as an anion (I) of the title compound are interesting compounds because of the conjugation arising between the two phenyl groups. As a result, these compounds can be excited with UV light to induce conversion between the E and Z isomers (Irie, 2000; Momotake & Arai, 2004). Stilbenes have found wide spread applications as photoactive switches (Irie, 2000) owing to the absorption differences of the two isomers allowing for selective excitation of either isomer. Compound (I) is of particular interest because the photoconversion between the two isomers is suppressed resulting in intense fluorescence. Consequently, it is used as a textile fluorescent brightener (Bischof et al., 2001). Owing to our ongoing azomethine research with functional materials, (Bourgeaux et al., 2007, Pérez Guarìn et al., 2007, Dufresne et al., 2007, Bourgeaux & Skene, 2007) compound (I) is an appealing monomer for the synthesis of novel water soluble conjugated polyazomethines because of its two aryl amino groups. X-ray crystallography of this monomer was pursued to unequivocally confirm the regio substitution of the primary amines, the geometry of the unsaturated bond, and cation exchange, all of which cannot be confirmed by conventional methods.
The salient features of (I) derived from the crystal structures are the regiospecific positions of the two sulfonic anions located in the 4, 4' positions and the para substitution of the primary amines on the stilbene. Cation exchange of the H atoms with triethylammonium cations was also confirmed. These are of importance because they cannot be unequivocally confirmed by NMR spectroscopy. The E isomer of the unsaturated bond was also verified.
The mean plane described by the two benzenes and that of the central alkene of (I) are twisted by 16.05 (10)°. This is in contrast to analogous stilbenes whose mean plane angles are considerably smaller, i.e., 2.72 ° (Wang et al., 2005) and 1.86 ° (Zhang et al., 2005). Similarly, the bond distance of the central alkene is also different from other stilbenes. For example, the C7—C7i bond length is 1.331 (4) Å compared to 1.317 Å and 1.316 Å for its unsubstituted analogue. Conversely, the C7—C6 bond distance (1.464 (2) Å) is comparable to that of its analogues that are 1.463 Å and 1.456 Å.
(I) forms a well defined three-dimensional network involving the ionic groups illustrated in Fig. 2. From this figure it is evident that the diaminostilbenes are distributed in parallel bc planes that are separated by 7.114 (16) Å. Similarly, the triethylammonium cations are located in different parallel planes. Each sulfonic anion coordinates to three triethylammonium cations. Two cations form a O···H—C bond with the sulfonic anion involving O3···H12B—C12 and O1···H10B—C10 with respective bond lengths of 2.438 (2) and 2.489 (2) Å and angles of 167 and 163 °. The third cation forms a hydrogen bond involving N2—H2···O2iv (Figure 3). The combined interactions involving the ionic species are illustrated in Figure 4.
Hydrogen bonding (Table 1) also occurs between the sulfonic anion and the primary amine of two parallel molecules of (I). An additional intermolecular hydrogen bond takes place between the second sulfonic anion acceptor and the triethylammonium cation donor of two different molecules of (I). These interactions are represented in Fig. 3.
For general background, see: Bischof et al. (2001); Bourgeaux & Skene (2007); Bourgeaux et al. (2007); Dufresne et al. (2007); Irie (2000); Momotake & Arai (2004); Pérez Guarìn et al. (2007). For related literature, see: Wang et al. (2005); Zhang et al. (2005).
Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: UdMX (Marris, 2004).
2C6H16N+·C14H12N2O6S22− | Z = 1 |
Mr = 572.79 | F(000) = 308 |
Triclinic, P1 | Dx = 1.219 Mg m−3 |
Hall symbol: -P 1 | Cu Kα radiation, λ = 1.54178 Å |
a = 8.5117 (4) Å | Cell parameters from 6392 reflections |
b = 8.5273 (4) Å | θ = 4.0–72.0° |
c = 12.0711 (5) Å | µ = 1.91 mm−1 |
α = 103.330 (2)° | T = 220 K |
β = 103.243 (2)° | Block, colourless |
γ = 106.142 (3)° | 0.29 × 0.21 × 0.19 mm |
V = 777.60 (6) Å3 |
Bruker SMART 2000 diffractometer | 2930 independent reflections |
Radiation source: X-ray Sealed Tube | 2772 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.044 |
Detector resolution: 5.5 pixels mm-1 | θmax = 72.0°, θmin = 4.0° |
ω scans | h = −10→10 |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | k = −8→9 |
Tmin = 0.640, Tmax = 0.696 | l = −14→14 |
8255 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.052 | H-atom parameters constrained |
wR(F2) = 0.150 | w = 1/[σ2(Fo2) + (0.1P)2 + 0.2755P] where P = (Fo2 + 2Fc2)/3 |
S = 1.08 | (Δ/σ)max = 0.001 |
2930 reflections | Δρmax = 0.54 e Å−3 |
176 parameters | Δρmin = −0.40 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.019 (2) |
2C6H16N+·C14H12N2O6S22− | γ = 106.142 (3)° |
Mr = 572.79 | V = 777.60 (6) Å3 |
Triclinic, P1 | Z = 1 |
a = 8.5117 (4) Å | Cu Kα radiation |
b = 8.5273 (4) Å | µ = 1.91 mm−1 |
c = 12.0711 (5) Å | T = 220 K |
α = 103.330 (2)° | 0.29 × 0.21 × 0.19 mm |
β = 103.243 (2)° |
Bruker SMART 2000 diffractometer | 2930 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2772 reflections with I > 2σ(I) |
Tmin = 0.640, Tmax = 0.696 | Rint = 0.044 |
8255 measured reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.150 | H-atom parameters constrained |
S = 1.08 | Δρmax = 0.54 e Å−3 |
2930 reflections | Δρmin = −0.40 e Å−3 |
176 parameters |
Experimental. X-ray crystallographic data for I were collected from a single-crystal sample, which was mounted on a loop fiber. Data were collected using a Bruker Platform diffractometer, equipped with a Bruker SMART 2 K Charged-Coupled Device (CCD) Area Detector using the program SMART and normal focus sealed tube source graphite monochromated Cu—Kα radiation. The crystal-to-detector distance was 4.908 cm, and the data collection was carried out in 512 x 512 pixel mode, utilizing 4 x 4 pixel binning. The initial unit-cell parameters were determined by a least-squares fit of the angular setting of strong reflections, collected by a 9.0 degree scan in 30 frames over four different parts of the reciprocal space (120 frames total). One complete sphere of data was collected, to better than 0.8 Å resolution. Upon completion of the data collection, the first 101 frames were recollected in order to improve the decay correction analysis. |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.11164 (5) | 0.81398 (5) | 0.80610 (4) | 0.0280 (2) | |
O1 | 0.2049 (2) | 0.9304 (2) | 0.92526 (13) | 0.0516 (5) | |
O2 | 0.0486 (2) | 0.9013 (2) | 0.72497 (14) | 0.0445 (4) | |
O3 | −0.0245 (2) | 0.6634 (2) | 0.80132 (17) | 0.0494 (5) | |
N1 | 0.7007 (2) | 0.7477 (2) | 0.87894 (16) | 0.0415 (4) | |
H1A | 0.7263 | 0.8137 | 0.9520 | 0.050* | |
H1B | 0.7749 | 0.7051 | 0.8575 | 0.050* | |
N2 | 0.0671 (3) | 0.8267 (3) | 0.23644 (19) | 0.0463 (5) | |
H2 | 0.0294 | 0.9185 | 0.2417 | 0.056* | |
C1 | 0.2603 (2) | 0.7335 (2) | 0.75102 (15) | 0.0242 (4) | |
C2 | 0.4227 (2) | 0.7782 (2) | 0.83059 (16) | 0.0280 (4) | |
H2A | 0.4523 | 0.8550 | 0.9080 | 0.034* | |
C3 | 0.5441 (2) | 0.7109 (2) | 0.79795 (16) | 0.0291 (4) | |
C4 | 0.4967 (2) | 0.6014 (3) | 0.68024 (17) | 0.0348 (4) | |
H4 | 0.5763 | 0.5569 | 0.6547 | 0.042* | |
C5 | 0.3343 (3) | 0.5586 (3) | 0.60167 (17) | 0.0351 (4) | |
H5 | 0.3067 | 0.4852 | 0.5234 | 0.042* | |
C6 | 0.2085 (2) | 0.6197 (2) | 0.63331 (15) | 0.0277 (4) | |
C7 | 0.0347 (2) | 0.5670 (2) | 0.54995 (15) | 0.0307 (4) | |
H7 | −0.0332 | 0.6330 | 0.5684 | 0.037* | |
C8 | 0.0904 (4) | 0.7980 (4) | 0.3540 (3) | 0.0622 (7) | |
H8A | 0.1335 | 0.7026 | 0.3532 | 0.075* | |
H8B | −0.0214 | 0.7651 | 0.3680 | 0.075* | |
C9 | 0.2148 (5) | 0.9560 (5) | 0.4557 (3) | 0.0858 (11) | |
H9A | 0.3288 | 0.9820 | 0.4468 | 0.129* | |
H9B | 0.2186 | 0.9345 | 0.5316 | 0.129* | |
H9C | 0.1767 | 1.0528 | 0.4538 | 0.129* | |
C10 | 0.2245 (5) | 0.8729 (4) | 0.2002 (3) | 0.0729 (9) | |
H10A | 0.3066 | 0.9830 | 0.2573 | 0.088* | |
H10B | 0.1940 | 0.8890 | 0.1212 | 0.088* | |
C11 | 0.3116 (6) | 0.7401 (6) | 0.1942 (6) | 0.130 (2) | |
H11A | 0.3452 | 0.7256 | 0.2726 | 0.195* | |
H11B | 0.4129 | 0.7782 | 0.1699 | 0.195* | |
H11C | 0.2323 | 0.6313 | 0.1364 | 0.195* | |
C12 | −0.0755 (4) | 0.6737 (4) | 0.1384 (3) | 0.0648 (8) | |
H12A | −0.0741 | 0.6869 | 0.0600 | 0.078* | |
H12B | −0.0526 | 0.5681 | 0.1416 | 0.078* | |
C13 | −0.2488 (4) | 0.6566 (4) | 0.1500 (3) | 0.0773 (9) | |
H13A | −0.2557 | 0.6286 | 0.2226 | 0.116* | |
H13B | −0.3357 | 0.5656 | 0.0811 | 0.116* | |
H13C | −0.2684 | 0.7642 | 0.1537 | 0.116* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0284 (3) | 0.0280 (3) | 0.0336 (3) | 0.0166 (2) | 0.0152 (2) | 0.00674 (19) |
O1 | 0.0486 (9) | 0.0658 (11) | 0.0379 (8) | 0.0347 (8) | 0.0133 (7) | −0.0061 (7) |
O2 | 0.0582 (9) | 0.0408 (9) | 0.0499 (9) | 0.0359 (7) | 0.0203 (7) | 0.0164 (7) |
O3 | 0.0405 (8) | 0.0406 (9) | 0.0872 (12) | 0.0223 (7) | 0.0430 (8) | 0.0244 (8) |
N1 | 0.0283 (8) | 0.0525 (11) | 0.0418 (9) | 0.0206 (7) | 0.0121 (7) | 0.0023 (8) |
N2 | 0.0646 (12) | 0.0398 (10) | 0.0619 (12) | 0.0348 (9) | 0.0345 (10) | 0.0311 (9) |
C1 | 0.0259 (8) | 0.0232 (8) | 0.0283 (8) | 0.0116 (6) | 0.0143 (7) | 0.0077 (6) |
C2 | 0.0276 (9) | 0.0286 (9) | 0.0288 (8) | 0.0110 (7) | 0.0135 (7) | 0.0045 (6) |
C3 | 0.0252 (8) | 0.0313 (9) | 0.0352 (9) | 0.0118 (7) | 0.0157 (7) | 0.0098 (7) |
C4 | 0.0332 (10) | 0.0409 (11) | 0.0370 (10) | 0.0188 (8) | 0.0212 (8) | 0.0072 (8) |
C5 | 0.0371 (10) | 0.0423 (11) | 0.0282 (9) | 0.0183 (8) | 0.0166 (8) | 0.0037 (7) |
C6 | 0.0310 (9) | 0.0302 (9) | 0.0257 (8) | 0.0133 (7) | 0.0134 (7) | 0.0079 (7) |
C7 | 0.0333 (9) | 0.0336 (10) | 0.0284 (9) | 0.0163 (7) | 0.0117 (7) | 0.0081 (7) |
C8 | 0.0701 (17) | 0.0711 (19) | 0.0644 (17) | 0.0320 (15) | 0.0279 (14) | 0.0403 (14) |
C9 | 0.086 (2) | 0.102 (3) | 0.068 (2) | 0.029 (2) | 0.0112 (17) | 0.0407 (19) |
C10 | 0.096 (2) | 0.0607 (18) | 0.106 (2) | 0.0428 (16) | 0.073 (2) | 0.0467 (17) |
C11 | 0.120 (4) | 0.097 (3) | 0.240 (7) | 0.071 (3) | 0.128 (4) | 0.062 (4) |
C12 | 0.089 (2) | 0.0455 (15) | 0.0626 (16) | 0.0323 (14) | 0.0167 (15) | 0.0184 (12) |
C13 | 0.076 (2) | 0.0530 (17) | 0.095 (2) | 0.0094 (15) | 0.0166 (18) | 0.0346 (16) |
S1—O1 | 1.4370 (15) | C7—C7i | 1.331 (4) |
S1—O3 | 1.4502 (15) | C7—H7 | 0.94 |
S1—O2 | 1.4560 (15) | C8—C9 | 1.513 (5) |
S1—C1 | 1.7814 (17) | C8—H8A | 0.98 |
N1—C3 | 1.364 (2) | C8—H8B | 0.98 |
N1—H1A | 0.87 | C9—H9A | 0.97 |
N1—H1B | 0.87 | C9—H9B | 0.97 |
N2—C8 | 1.474 (3) | C9—H9C | 0.97 |
N2—C10 | 1.482 (3) | C10—C11 | 1.514 (5) |
N2—C12 | 1.525 (4) | C10—H10A | 0.98 |
N2—H2 | 0.92 | C10—H10B | 0.98 |
C1—C2 | 1.381 (2) | C11—H11A | 0.97 |
C1—C6 | 1.412 (2) | C11—H11B | 0.97 |
C2—C3 | 1.401 (2) | C11—H11C | 0.97 |
C2—H2A | 0.94 | C12—C13 | 1.484 (5) |
C3—C4 | 1.403 (3) | C12—H12A | 0.98 |
C4—C5 | 1.379 (3) | C12—H12B | 0.98 |
C4—H4 | 0.94 | C13—H13A | 0.97 |
C5—C6 | 1.403 (3) | C13—H13B | 0.97 |
C5—H5 | 0.94 | C13—H13C | 0.97 |
C6—C7 | 1.464 (2) | ||
O1—S1—O3 | 113.87 (11) | N2—C8—C9 | 112.4 (2) |
O1—S1—O2 | 111.88 (10) | N2—C8—H8A | 109.1 |
O3—S1—O2 | 111.58 (10) | C9—C8—H8A | 109.1 |
O1—S1—C1 | 106.96 (9) | N2—C8—H8B | 109.1 |
O3—S1—C1 | 105.30 (8) | C9—C8—H8B | 109.1 |
O2—S1—C1 | 106.64 (8) | H8A—C8—H8B | 107.9 |
C3—N1—H1A | 120 | C8—C9—H9A | 109.5 |
C3—N1—H1B | 120 | C8—C9—H9B | 109.5 |
H1A—N1—H1B | 120 | H9A—C9—H9B | 109.5 |
C8—N2—C10 | 115.9 (2) | C8—C9—H9C | 109.5 |
C8—N2—C12 | 111.0 (2) | H9A—C9—H9C | 109.5 |
C10—N2—C12 | 110.3 (2) | H9B—C9—H9C | 109.5 |
C8—N2—H2 | 106.3 | N2—C10—C11 | 113.8 (3) |
C10—N2—H2 | 106.3 | N2—C10—H10A | 108.8 |
C12—N2—H2 | 106.3 | C11—C10—H10A | 108.8 |
C2—C1—C6 | 122.14 (16) | N2—C10—H10B | 108.8 |
C2—C1—S1 | 117.11 (13) | C11—C10—H10B | 108.8 |
C6—C1—S1 | 120.61 (13) | H10A—C10—H10B | 107.7 |
C1—C2—C3 | 121.14 (16) | C10—C11—H11A | 109.5 |
C1—C2—H2A | 119.4 | C10—C11—H11B | 109.5 |
C3—C2—H2A | 119.4 | H11A—C11—H11B | 109.5 |
N1—C3—C2 | 120.89 (17) | C10—C11—H11C | 109.5 |
N1—C3—C4 | 121.55 (17) | H11A—C11—H11C | 109.5 |
C2—C3—C4 | 117.54 (16) | H11B—C11—H11C | 109.5 |
C5—C4—C3 | 120.61 (17) | C13—C12—N2 | 112.7 (2) |
C5—C4—H4 | 119.7 | C13—C12—H12A | 109.1 |
C3—C4—H4 | 119.7 | N2—C12—H12A | 109.1 |
C4—C5—C6 | 122.96 (17) | C13—C12—H12B | 109.1 |
C4—C5—H5 | 118.5 | N2—C12—H12B | 109.1 |
C6—C5—H5 | 118.5 | H12A—C12—H12B | 107.8 |
C5—C6—C1 | 115.55 (16) | C12—C13—H13A | 109.5 |
C5—C6—C7 | 122.02 (16) | C12—C13—H13B | 109.5 |
C1—C6—C7 | 122.43 (16) | H13A—C13—H13B | 109.5 |
C7i—C7—C6 | 125.2 (2) | C12—C13—H13C | 109.5 |
C7i—C7—H7 | 117.4 | H13A—C13—H13C | 109.5 |
C6—C7—H7 | 117.4 | H13B—C13—H13C | 109.5 |
O1—S1—C1—C2 | 6.48 (18) | C4—C5—C6—C7 | −177.47 (18) |
O3—S1—C1—C2 | −114.99 (15) | C2—C1—C6—C5 | −1.6 (3) |
O2—S1—C1—C2 | 126.33 (15) | S1—C1—C6—C5 | −177.21 (14) |
O1—S1—C1—C6 | −177.67 (15) | C2—C1—C6—C7 | 177.78 (17) |
O3—S1—C1—C6 | 60.86 (17) | S1—C1—C6—C7 | 2.1 (2) |
O2—S1—C1—C6 | −57.81 (16) | C5—C6—C7—C7i | 15.7 (4) |
C6—C1—C2—C3 | −0.4 (3) | C1—C6—C7—C7i | −163.6 (2) |
S1—C1—C2—C3 | 175.34 (14) | C10—N2—C8—C9 | 60.4 (4) |
C1—C2—C3—N1 | −176.21 (18) | C12—N2—C8—C9 | −172.7 (3) |
C1—C2—C3—C4 | 2.2 (3) | C8—N2—C10—C11 | 58.6 (5) |
N1—C3—C4—C5 | 176.50 (19) | C12—N2—C10—C11 | −68.6 (4) |
C2—C3—C4—C5 | −1.9 (3) | C8—N2—C12—C13 | 68.8 (3) |
C3—C4—C5—C6 | −0.2 (3) | C10—N2—C12—C13 | −161.4 (2) |
C4—C5—C6—C1 | 1.9 (3) |
Symmetry code: (i) −x, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O1ii | 0.87 | 2.17 | 2.946 (2) | 149 |
N1—H1B···O3iii | 0.87 | 2.06 | 2.915 (2) | 166 |
N2—H2···O2iv | 0.92 | 1.84 | 2.747 (2) | 171 |
Symmetry codes: (ii) −x+1, −y+2, −z+2; (iii) x+1, y, z; (iv) −x, −y+2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | 2C6H16N+·C14H12N2O6S22− |
Mr | 572.79 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 220 |
a, b, c (Å) | 8.5117 (4), 8.5273 (4), 12.0711 (5) |
α, β, γ (°) | 103.330 (2), 103.243 (2), 106.142 (3) |
V (Å3) | 777.60 (6) |
Z | 1 |
Radiation type | Cu Kα |
µ (mm−1) | 1.91 |
Crystal size (mm) | 0.29 × 0.21 × 0.19 |
Data collection | |
Diffractometer | Bruker SMART 2000 |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.640, 0.696 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8255, 2930, 2772 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.150, 1.08 |
No. of reflections | 2930 |
No. of parameters | 176 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.54, −0.40 |
Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1997) and ORTEP-3 (Farrugia, 1997), UdMX (Marris, 2004).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···O1i | 0.87 | 2.17 | 2.946 (2) | 149 |
N1—H1B···O3ii | 0.87 | 2.06 | 2.915 (2) | 166 |
N2—H2···O2iii | 0.92 | 1.84 | 2.747 (2) | 171 |
Symmetry codes: (i) −x+1, −y+2, −z+2; (ii) x+1, y, z; (iii) −x, −y+2, −z+1. |
Stilbenes such as an anion (I) of the title compound are interesting compounds because of the conjugation arising between the two phenyl groups. As a result, these compounds can be excited with UV light to induce conversion between the E and Z isomers (Irie, 2000; Momotake & Arai, 2004). Stilbenes have found wide spread applications as photoactive switches (Irie, 2000) owing to the absorption differences of the two isomers allowing for selective excitation of either isomer. Compound (I) is of particular interest because the photoconversion between the two isomers is suppressed resulting in intense fluorescence. Consequently, it is used as a textile fluorescent brightener (Bischof et al., 2001). Owing to our ongoing azomethine research with functional materials, (Bourgeaux et al., 2007, Pérez Guarìn et al., 2007, Dufresne et al., 2007, Bourgeaux & Skene, 2007) compound (I) is an appealing monomer for the synthesis of novel water soluble conjugated polyazomethines because of its two aryl amino groups. X-ray crystallography of this monomer was pursued to unequivocally confirm the regio substitution of the primary amines, the geometry of the unsaturated bond, and cation exchange, all of which cannot be confirmed by conventional methods.
The salient features of (I) derived from the crystal structures are the regiospecific positions of the two sulfonic anions located in the 4, 4' positions and the para substitution of the primary amines on the stilbene. Cation exchange of the H atoms with triethylammonium cations was also confirmed. These are of importance because they cannot be unequivocally confirmed by NMR spectroscopy. The E isomer of the unsaturated bond was also verified.
The mean plane described by the two benzenes and that of the central alkene of (I) are twisted by 16.05 (10)°. This is in contrast to analogous stilbenes whose mean plane angles are considerably smaller, i.e., 2.72 ° (Wang et al., 2005) and 1.86 ° (Zhang et al., 2005). Similarly, the bond distance of the central alkene is also different from other stilbenes. For example, the C7—C7i bond length is 1.331 (4) Å compared to 1.317 Å and 1.316 Å for its unsubstituted analogue. Conversely, the C7—C6 bond distance (1.464 (2) Å) is comparable to that of its analogues that are 1.463 Å and 1.456 Å.
(I) forms a well defined three-dimensional network involving the ionic groups illustrated in Fig. 2. From this figure it is evident that the diaminostilbenes are distributed in parallel bc planes that are separated by 7.114 (16) Å. Similarly, the triethylammonium cations are located in different parallel planes. Each sulfonic anion coordinates to three triethylammonium cations. Two cations form a O···H—C bond with the sulfonic anion involving O3···H12B—C12 and O1···H10B—C10 with respective bond lengths of 2.438 (2) and 2.489 (2) Å and angles of 167 and 163 °. The third cation forms a hydrogen bond involving N2—H2···O2iv (Figure 3). The combined interactions involving the ionic species are illustrated in Figure 4.
Hydrogen bonding (Table 1) also occurs between the sulfonic anion and the primary amine of two parallel molecules of (I). An additional intermolecular hydrogen bond takes place between the second sulfonic anion acceptor and the triethylammonium cation donor of two different molecules of (I). These interactions are represented in Fig. 3.