trans-1-(2-Quinolyl)-2-(2-thienyl)­ethyl­ene

The title compound, C₁₅H₁₁NS, contains a thio­phene ring and a quinoline moiety connected by an ethyl­ene bridge, which shows a trans configuration. The thio­phene ring is disordered over two sites by rotation about the exocyclic C-C bond.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.046
• wR factor = 0.109
• Data-to-parameter ratio = 15.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           27.18
         From the CIF: _reflns_number_total               2438
         Count of symmetry unique reflns         1571
         Completeness (_total/calc)            155.19%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured       867
         Fraction of Friedel pairs measured     0.552
         Are heavy atom types Z>Si present          yes
          Please check that the estimate of the number of Friedel pairs is
          correct. If it is not, please give the correct count in the
          _publ_section_exptl_refinement section of the submitted CIF.

---

S1. Comment

Many synthetic antimalaric products, like chloroquinine (Joule et al., 1995, and references therein), possess a skeleton based on the quinolenic moiety. Most of these products are active in biological processes (Zouhiri et al., 2000). Moreover, bichromophors containing two or more quinoline molecules linked by hydrocarbon channels are known as active chelatants of metallic ions (Wong & Wong, 1996). Bichromophors containing the quinoline nucleus (Radhakrishnan et al., 1995; Wang & Ho, 1997) or naphthalene (Arai & Tokumaru, 1993) exibit the same behaviour as those containing pyridine (Favaro et al., 1973) or benzene derivatives (Létard et al., 1993; Lewis & Yang, 1997). Furthermore, the photophysical aspect of styrylquinoline derivatives is still attracting attention of many researchers (Arai et al., 1994).

Based on the acidic characteristic of methyl protons in the 2-position of pyridine and quinoline, we have adapted the condensation reaction of 2-picoline on benzaldehyde referring to the conventional synthetic method reported in the literature (Wang & Ho, 1997). This process results in quinolenic olefins by means of condensation of 2-methylquinoline on different kind of aldehydes. All products obtained by this reaction have a trans configuration. We did check this result by our numerous other spectroscopical investigations, mainly IR, mass and NMR (¹H and ¹³C), notably by the study of the chemical displacements of the ethylic protons by ¹H NMR as by IR absorption bands of the deformations out of the ethylenic double bond. On the other hand, we concluded on the same conformation when we studied the crystal structure of trans-1-(2-quinolyl)-2-(2-thienyl)ethylene and trans-bis(4-quinolyl)ethylene (Jerdioui et al., 1999). We decribe here the synthesis and X-ray crystal structure analysis of the title compound, (I). The crystal data are in agreement with the spectroscopical investigations, particularly the molecular conformation. The present study will allow us to understand more deeply the influence of the thienyl group on the behaviour of this derivative, both at its ground and exited state.

The thiophene ring and the quinoline moiety are nearly coplanar, the dihedral angle between them is 13.4 (1)°. The ethylenic double bond is trans-configured.

S2. Experimental

2 g (13.9 mmol) of 2-methylquinoline, 2.6 ml of anhydrous acetic acid and 2.6 ml of acetic acid were mixed in a 100 ml flask crowned by a refrigerant. After heating to 333 K, we added 17 mmol of thienaldehyde. The mixture was then heated at 393 K for 2 h, the evolution of the reaction being followed by CCM [please define]. After cooling to room temperature, we neutralized the solution with CaCO₃. The extraction was realised by dichloromethane. Elimination of the solvent produced a yellow solid, which was then recrystallized in a mixture of equimolar hexane/dichloromethane, to yield yellowish crystals in the form of plates.

S3. Refinement

The thiophene ring is disordered. The resolution of the data did not allow two distinct positions for the S and C atoms to be distinguished. Only one peak was found for each atom in the difference map. Thus, a C and an S atom were refined sharing the same position and the same displacement parameters and just refining the site-occupation factor of the respecitve C and S atoms in order to determine the ratio of the different orientations, which turned out to be 0.820 (3) to 0.180 (3). All H atoms except those of the disordered atoms were located by difference Fourier synthesis and refined with fixed individual displacement parameters [U_iso(H) = 1.2U_eq(C)] using a riding model with C—H = 0.95 Å.

Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Sheldrick, 1991).

Figures

Fig. 1. A perspective view of the title compound with the atom-numbering scheme. Displacement ellipsoids are at the 50% probability level. Only the main conformation is shown.

(I)

Crystal data

C15H11NS	F(000) = 496
Mr = 237.31	Dx = 1.323 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 512 reflections
a = 6.0100 (12) Å	θ = 1–20°
b = 7.8502 (16) Å	µ = 0.25 mm^−1
c = 25.258 (5) Å	T = 173 K
V = 1191.7 (4) Å^3	Plate, yellow
Z = 4	0.41 × 0.26 × 0.06 mm

Data collection

Siemens CCD three-circle diffractometer	2438 independent reflections
Radiation source: fine-focus sealed tube	1882 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.047
ω scans	θmax = 27.2°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −7→7
Tmin = 0.891, Tmax = 0.976	k = −9→9
9574 measured reflections	l = −30→31

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.046	H-atom parameters constrained
wR(F^2) = 0.109	w = 1/[σ^2(Fo^2) + (0.0462P)^2 + 0.4035P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max < 0.001
2438 reflections	Δρmax = 0.41 e Å^−3
155 parameters	Δρmin = −0.20 e Å^−3
0 restraints	Absolute structure: Flack (1983), 962 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.07 (15)

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
S1	0.24475 (16)	0.18220 (10)	0.82079 (3)	0.0392 (3)	0.820 (3)
C1	0.24475 (16)	0.18220 (10)	0.82079 (3)	0.0392 (3)	0.180 (3)
H1	0.3840	0.1278	0.8264	0.047*	0.180 (3)
C2	0.1326 (5)	0.2866 (4)	0.76861 (10)	0.0358 (7)
S3	−0.0843 (3)	0.3430 (3)	0.77941 (8)	0.0436 (8)	0.180 (3)
C3	−0.0843 (3)	0.3430 (3)	0.77941 (8)	0.0436 (8)	0.820 (3)
H3	−0.1777	0.4023	0.7553	0.052*	0.820 (3)
C4	−0.1442 (5)	0.2966 (4)	0.83413 (11)	0.0427 (7)
H4	−0.2826	0.3252	0.8500	0.051*
C5	0.0185 (6)	0.2103 (4)	0.85912 (11)	0.0464 (8)
H5	0.0071	0.1703	0.8945	0.056*
C6	0.2477 (6)	0.3110 (4)	0.71807 (10)	0.0404 (6)
H6	0.1867	0.3907	0.6938	0.049*
C7	0.4294 (5)	0.2301 (4)	0.70412 (11)	0.0410 (8)
H7	0.4856	0.1457	0.7275	0.049*
C11	0.5527 (5)	0.2615 (4)	0.65442 (10)	0.0357 (7)
N11	0.4713 (4)	0.3728 (3)	0.61946 (9)	0.0339 (6)
C12	0.6003 (4)	0.4096 (3)	0.57595 (10)	0.0289 (6)
C13	0.5235 (5)	0.5300 (4)	0.53933 (11)	0.0388 (7)
H13	0.3820	0.5814	0.5443	0.047*
C14	0.6492 (6)	0.5740 (4)	0.49668 (12)	0.0459 (8)
H14	0.5940	0.6559	0.4723	0.055*
C15	0.8588 (6)	0.5009 (4)	0.48811 (11)	0.0440 (8)
H15	0.9445	0.5330	0.4581	0.053*
C16	0.9399 (5)	0.3823 (4)	0.52325 (10)	0.0364 (7)
H16	1.0819	0.3324	0.5175	0.044*
C17	0.8130 (4)	0.3345 (3)	0.56778 (10)	0.0279 (6)
C18	0.8857 (5)	0.2142 (3)	0.60548 (10)	0.0374 (7)
H18	1.0247	0.1583	0.6009	0.045*
C19	0.7591 (5)	0.1785 (4)	0.64777 (10)	0.0395 (6)
H19	0.8081	0.0975	0.6732	0.047*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0476 (5)	0.0405 (5)	0.0296 (4)	0.0103 (5)	−0.0020 (4)	0.0042 (4)
C1	0.0476 (5)	0.0405 (5)	0.0296 (4)	0.0103 (5)	−0.0020 (4)	0.0042 (4)
C2	0.0426 (18)	0.0320 (15)	0.0328 (14)	−0.0075 (14)	0.0018 (12)	−0.0056 (12)
S3	0.0455 (14)	0.0485 (14)	0.0369 (11)	−0.0018 (11)	−0.0041 (9)	0.0030 (9)
C3	0.0455 (14)	0.0485 (14)	0.0369 (11)	−0.0018 (11)	−0.0041 (9)	0.0030 (9)
C4	0.0409 (17)	0.0425 (17)	0.0448 (16)	−0.0033 (15)	0.0093 (13)	−0.0074 (14)
C5	0.069 (2)	0.0368 (18)	0.0337 (15)	−0.0011 (17)	0.0097 (15)	0.0026 (13)
C6	0.0440 (17)	0.0343 (14)	0.0430 (14)	−0.0042 (18)	−0.0095 (16)	−0.0022 (12)
C7	0.0443 (19)	0.0361 (17)	0.0426 (16)	−0.0037 (15)	−0.0037 (14)	0.0031 (14)
C11	0.0458 (18)	0.0335 (15)	0.0277 (14)	−0.0101 (13)	−0.0035 (13)	−0.0006 (12)
N11	0.0282 (13)	0.0367 (14)	0.0369 (13)	−0.0050 (10)	0.0040 (10)	−0.0121 (11)
C12	0.0278 (15)	0.0270 (13)	0.0319 (14)	−0.0046 (12)	−0.0037 (12)	−0.0065 (11)
C13	0.0377 (18)	0.0345 (17)	0.0442 (16)	0.0019 (13)	−0.0099 (14)	−0.0032 (13)
C14	0.057 (2)	0.0388 (17)	0.0415 (17)	0.0002 (17)	−0.0062 (16)	0.0095 (15)
C15	0.058 (2)	0.0442 (18)	0.0299 (15)	−0.0172 (17)	0.0084 (15)	−0.0009 (14)
C16	0.0349 (17)	0.0383 (16)	0.0362 (15)	−0.0047 (14)	0.0040 (13)	−0.0116 (13)
C17	0.0288 (15)	0.0261 (13)	0.0287 (12)	−0.0006 (11)	−0.0027 (10)	−0.0065 (12)
C18	0.0369 (17)	0.0345 (16)	0.0407 (15)	0.0026 (14)	−0.0087 (14)	−0.0044 (13)
C19	0.0478 (17)	0.0383 (15)	0.0326 (13)	0.0019 (18)	−0.0071 (15)	0.0020 (13)

Geometric parameters (Å, º)

S1—C5	1.684 (3)	N11—C12	1.375 (3)
S1—C2	1.692 (3)	C12—C13	1.401 (4)
S1—H1	0.95	C12—C17	1.422 (4)
C2—S3	1.404 (3)	C13—C14	1.360 (4)
C2—C6	1.465 (4)	C13—H13	0.95
S3—C4	1.474 (3)	C14—C15	1.401 (5)
S3—H3	0.9501	C14—H14	0.95
C4—C5	1.346 (4)	C15—C16	1.376 (4)
C4—H4	0.95	C15—H15	0.95
C5—H5	0.9502	C16—C17	1.410 (4)
C6—C7	1.312 (4)	C16—H16	0.95
C6—H6	0.95	C17—C18	1.411 (4)
C7—C11	1.478 (4)	C18—C19	1.341 (4)
C7—H7	0.95	C18—H18	0.95
C11—N11	1.335 (3)	C19—H19	0.95
C11—C19	1.411 (4)
C5—S1—C2	93.59 (16)	N11—C12—C13	118.9 (3)
C5—S1—H1	133.2	N11—C12—C17	122.4 (2)
C2—S1—H1	133.2	C13—C12—C17	118.7 (3)
S3—C2—C6	124.5 (3)	C14—C13—C12	120.7 (3)
S3—C2—S1	111.81 (19)	C14—C13—H13	119.6
C6—C2—S1	123.7 (2)	C12—C13—H13	119.6
C2—S3—C4	109.3 (2)	C13—C14—C15	121.2 (3)
C2—S3—H3	125.4	C13—C14—H14	119.4
C4—S3—H3	125.3	C15—C14—H14	119.4
C5—C4—S3	112.7 (3)	C16—C15—C14	119.8 (3)
C5—C4—H4	123.8	C16—C15—H15	120.1
S3—C4—H4	123.4	C14—C15—H15	120.1
C4—C5—S1	112.5 (2)	C15—C16—C17	120.2 (3)
C4—C5—H5	123.7	C15—C16—H16	119.9
S1—C5—H5	123.8	C17—C16—H16	119.9
C7—C6—C2	124.3 (3)	C16—C17—C18	123.3 (2)
C7—C6—H6	117.8	C16—C17—C12	119.4 (2)
C2—C6—H6	117.8	C18—C17—C12	117.3 (2)
C6—C7—C11	124.4 (3)	C19—C18—C17	120.1 (3)
C6—C7—H7	117.8	C19—C18—H18	120.0
C11—C7—H7	117.8	C17—C18—H18	120.0
N11—C11—C19	123.1 (2)	C18—C19—C11	119.8 (2)
N11—C11—C7	119.2 (3)	C18—C19—H19	120.1
C19—C11—C7	117.7 (2)	C11—C19—H19	120.1
C11—N11—C12	117.3 (2)
C5—S1—C2—S3	−1.0 (2)	N11—C12—C13—C14	177.9 (3)
C5—S1—C2—C6	−179.8 (2)	C17—C12—C13—C14	0.2 (4)
C6—C2—S3—C4	−179.8 (2)	C12—C13—C14—C15	−0.1 (4)
S1—C2—S3—C4	1.5 (3)	C13—C14—C15—C16	0.0 (4)
C2—S3—C4—C5	−1.4 (3)	C14—C15—C16—C17	−0.1 (4)
S3—C4—C5—S1	0.6 (3)	C15—C16—C17—C18	−179.9 (3)
C2—S1—C5—C4	0.2 (3)	C15—C16—C17—C12	0.2 (4)
S3—C2—C6—C7	−165.6 (3)	N11—C12—C17—C16	−177.8 (2)
S1—C2—C6—C7	13.0 (4)	C13—C12—C17—C16	−0.2 (4)
C2—C6—C7—C11	−176.4 (3)	N11—C12—C17—C18	2.2 (3)
C6—C7—C11—N11	−3.6 (4)	C13—C12—C17—C18	179.8 (2)
C6—C7—C11—C19	172.9 (3)	C16—C17—C18—C19	178.0 (3)
C19—C11—N11—C12	−1.8 (4)	C12—C17—C18—C19	−2.0 (4)
C7—C11—N11—C12	174.5 (2)	C17—C18—C19—C11	0.0 (4)
C11—N11—C12—C13	−177.9 (2)	N11—C11—C19—C18	2.0 (4)
C11—N11—C12—C17	−0.4 (3)	C7—C11—C19—C18	−174.3 (3)