2-(2,4,5-Trimethoxy­phen­yl)-1,3-benzo­thia­zole

In the title compound, C₁₆H₁₅NO₃S, the benzothia­zole ring system is essentially planar and makes a dihedral angle of 4.5 (2)° with the plane of the attached benzene ring. The 4- and 5-meth­oxy groups are coplanar with the attached benzene ring, while the 2-meth­oxy group is rotated slightly out of the plane [4.8 (3)°].

Key indicators

• Single-crystal X-ray study
• T = 273 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.034
• wR factor = 0.089
• Data-to-parameter ratio = 15.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT322_ALERT_2_C Check Hybridisation of  S1     in Main Residue .          ?

Alert level G
REFLT03_ALERT_4_G 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.
           From the CIF: _diffrn_reflns_theta_max           27.50
           From the CIF: _reflns_number_total               3309
           Count of symmetry unique reflns         1935
           Completeness (_total/calc)            171.01%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1374
           Fraction of Friedel pairs measured     0.710
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   1 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
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

2-arylbenzothiazole derivatives have been well known for their biological and pharmaceutical activities, such as antitumor, antiviral, antimicrobial activities and potent inhibitory activity (Altanla et al., 1999). Recently, 2-arylbenzothiazole derivatives have also attracted increasing attention due to their application in the area of organic optoelectronic materials, such as second-order nonlinear optical (NLO) materials (Leng et al., 2001), two-photo absorption (TPA) chromophores (Prasad et al., 2001), photoconducting materials (Kalle & Br, 1962), liquid crystals (Kawamoto et al., 2003) and efficient fluorophores (Barbara et al., 1980). The title compound, (I), plays a very important role in the electroactive and photoative materials, which emits blue luminescence in both solid state and organic solution upon by UV-light at ambient temperature.

In the crystal structure of the title molecule, the five-member thiazole ring is almost coplanar with its fused benzene ring, and the dihedral angle between the mean planes of the rings is only 0.3 (1) ° (Fig. 1). The benzothiazole ring is twisted slightly away from the plane of C13—C8 phenyl ring due to the steric hindrance. The dihedral angle between them is 4.5 (2) °. 2-Methoxy group is twisted out of the C13—C8 benzene plane due to the steric interference from the adjacent benzothiazole moiety. The C10—C9—O1—C16 torsion angle is 4.8 (3) °. the other two methoxy groups almost lies in the C8—C13 benzene plane. The bond distances of C7—N1 (1.301 (2) Å) and C1—N1 (1.387 (2) Å), have an average trend, which is a result of π-electron delocalization. Similarly, the bond lengths of C6—S1 (1.7292 (19) Å) and C7—S1 (1.7588 (17) Å) have small difference (Table 1).

In the stacking structure of compound (I), there exists an effective overlap of the phenyl rings between two adjacent molecules (Fig. 2). The shortest separation distance is about 3.502 Å. There are also interactions between C15—H and the benzene ring of adjacent molecules, whose shortest distance is 3.494 Å.

Related literature

For related literature, see: Kalle & Br (1962); Barbara et al. (1980); Leng et al. (2001); Kannan et al. (2001); Mori et al. (2003); Oren et al. (1999); Altanla et al. (1999); Prasad et al. (2001); Kawamoto et al. (2003).

S2. Experimental

2-aminothiophenol and 2, 4, 5-trimethoxybenzaldehyde were purchased from Acros and used without further purification. 2-aminothiophenol (1.25 g, 10 mmol) and 2, 4, 5-trimethoxybenzaldehyde (1.96 g, 10 mmol) were dissolved in 20 ml of DMSO under argon atmosphere. The mixture was heated at 473 K for 0.5 h. After cooling, the solution was poured into ice water, and then adjusted the solution to pH 8–9 with 1 N NaHCO₃ solution. The precipitate was filtered, washed with a great deal of water several times. After dried under vacuum, the crude product was recrystallized with ethanol. Light green crystal, yield: 90%. ¹H NMR (CDCl₃, p.p.m.) 8.09 (s, 1H), 8.03 (d, J = 7.2 Hz, 1H), 7.88 (d, J = 7.8 Hz, 1H), 7.45 (t, J = 7.5 Hz, 1H), 7.33 (t, J = 7.2 Hz, 1H), 6.61 (s, 1H), 4.04 (s, 3H), 4.01 (s, 3H), 3.96 (s, 3H). mp = 471–472 K. Anal.Calcd for C₁₆H₁₅O₃NS: C, 63.77; H, 5.01; N, 4.65. Found: C, 63.69; H, 4.96; N, 4.62%. MS (FAB): m/e, 301 (M⁺).

S3. Refinement

H atoms were placed in idealized positions and constrained to ride on their parent atoms with C—H = 0.93 Å, and with U_iso(H) = 1.2 U_eq(carrier atom).

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. Part of the crystal packing of (I), showing the intermolecular interactions. All hydrogen atoms have been omitted for clarity.

2-(2,4,5-Trimethoxyphenyl)-1,3-benzothiazole

Crystal data

C16H15NO3S	Z = 4
Mr = 301.35	F(000) = 632
Orthorhombic, P212121	Dx = 1.375 Mg m^−3
Hall symbol: P 2ac 2ab	Mo Kα radiation, λ = 0.71073 Å
a = 6.9897 (6) Å	µ = 0.23 mm^−1
b = 12.6809 (11) Å	T = 273 K
c = 16.4228 (14) Å	Block, green
V = 1455.6 (2) Å^3	0.18 × 0.12 × 0.08 mm

Data collection

Siemens SMART CCD area-detector diffractometer	3309 independent reflections
Radiation source: fine-focus sealed tube	2843 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
φ and ω scans	θmax = 27.5°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.960, Tmax = 0.982	k = −16→15
9473 measured reflections	l = −21→15

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)] = 0.034	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.089	w = 1/[σ^2(Fo^2) + (0.047P)^2 + 0.0899P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max = 0.001
3309 reflections	Δρmax = 0.20 e Å^−3
213 parameters	Δρmin = −0.18 e Å^−3
0 restraints	Absolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.06 (7)

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
C1	−0.0446 (3)	0.79063 (14)	0.78838 (11)	0.0448 (4)
C2	−0.2035 (3)	0.72585 (17)	0.77923 (14)	0.0592 (5)
C3	−0.3326 (3)	0.71829 (18)	0.84219 (15)	0.0657 (6)
C4	−0.3062 (3)	0.77359 (18)	0.91380 (15)	0.0638 (6)
C5	−0.1498 (3)	0.83768 (17)	0.92492 (14)	0.0590 (5)
C6	−0.0190 (3)	0.84597 (14)	0.86102 (12)	0.0463 (4)
C7	0.2260 (3)	0.87307 (13)	0.75684 (10)	0.0410 (4)
C8	0.3898 (2)	0.90527 (13)	0.70673 (10)	0.0399 (4)
C9	0.5369 (3)	0.96957 (14)	0.73449 (11)	0.0432 (4)
C10	0.6914 (3)	0.99462 (14)	0.68413 (11)	0.0452 (4)
C11	0.6967 (3)	0.95721 (13)	0.60518 (11)	0.0423 (4)
C12	0.5458 (3)	0.89504 (14)	0.57504 (11)	0.0436 (4)
C13	0.3979 (3)	0.86906 (13)	0.62575 (10)	0.0424 (4)
H13	0.3000	0.8263	0.6062	0.051*
C14	0.4136 (3)	0.80441 (18)	0.46223 (13)	0.0669 (6)
H14A	0.4039	0.7396	0.4921	0.100*
H14B	0.4411	0.7893	0.4062	0.100*
H14C	0.2949	0.8422	0.4660	0.100*
C15	0.9938 (3)	1.04209 (18)	0.57777 (14)	0.0623 (6)
H15A	0.9456	1.1112	0.5900	0.093*
H15C	1.0878	1.0470	0.5353	0.093*
H15B	1.0514	1.0124	0.6256	0.093*
C16	0.6571 (3)	1.07802 (17)	0.84273 (12)	0.0641 (6)
H16A	0.7822	1.0469	0.8404	0.096*
H16B	0.6264	1.0949	0.8982	0.096*
H16C	0.6552	1.1412	0.8106	0.096*
H2	−0.222 (3)	0.6833 (15)	0.7316 (14)	0.067 (7)*
H3	−0.450 (4)	0.6731 (19)	0.8373 (15)	0.082 (8)*
H4	−0.398 (3)	0.7704 (18)	0.9581 (14)	0.077 (7)*
H5	−0.128 (3)	0.8792 (16)	0.9739 (14)	0.067 (7)*
H10	0.788 (3)	1.0332 (13)	0.7063 (11)	0.043 (5)*
N1	0.0967 (2)	0.80764 (12)	0.73050 (9)	0.0461 (4)
O1	0.5212 (2)	1.00604 (12)	0.81193 (8)	0.0604 (4)
O2	0.84061 (18)	0.97636 (10)	0.55154 (8)	0.0537 (3)
O3	0.5617 (2)	0.86625 (11)	0.49516 (8)	0.0574 (4)
S1	0.18854 (8)	0.91984 (4)	0.85636 (3)	0.05518 (15)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0448 (10)	0.0467 (9)	0.0429 (10)	0.0012 (8)	0.0007 (8)	0.0006 (8)
C2	0.0579 (12)	0.0641 (12)	0.0556 (12)	−0.0135 (11)	0.0050 (11)	−0.0069 (10)
C3	0.0525 (12)	0.0691 (13)	0.0755 (15)	−0.0110 (11)	0.0099 (11)	−0.0008 (12)
C4	0.0585 (13)	0.0661 (13)	0.0669 (14)	−0.0005 (11)	0.0216 (12)	−0.0010 (11)
C5	0.0655 (13)	0.0604 (12)	0.0510 (11)	0.0045 (11)	0.0141 (10)	−0.0073 (10)
C6	0.0493 (10)	0.0450 (9)	0.0445 (10)	0.0021 (8)	0.0055 (8)	−0.0031 (8)
C7	0.0478 (10)	0.0398 (8)	0.0353 (9)	0.0033 (8)	−0.0023 (7)	−0.0032 (7)
C8	0.0438 (9)	0.0393 (8)	0.0366 (9)	0.0019 (7)	0.0001 (7)	−0.0001 (7)
C9	0.0497 (10)	0.0433 (9)	0.0366 (9)	0.0008 (8)	−0.0044 (8)	−0.0010 (7)
C10	0.0459 (10)	0.0431 (9)	0.0466 (10)	−0.0052 (9)	−0.0057 (9)	0.0004 (8)
C11	0.0422 (9)	0.0396 (8)	0.0451 (9)	0.0021 (8)	0.0023 (8)	0.0061 (7)
C12	0.0505 (10)	0.0434 (10)	0.0369 (9)	−0.0003 (8)	0.0026 (8)	0.0006 (7)
C13	0.0468 (10)	0.0397 (9)	0.0406 (9)	−0.0023 (7)	0.0013 (8)	−0.0024 (7)
C14	0.0804 (15)	0.0773 (14)	0.0432 (11)	−0.0204 (12)	0.0057 (11)	−0.0146 (11)
C15	0.0460 (11)	0.0729 (13)	0.0679 (13)	−0.0114 (10)	0.0046 (10)	0.0100 (11)
C16	0.0781 (14)	0.0650 (12)	0.0492 (11)	−0.0179 (12)	−0.0098 (11)	−0.0125 (10)
N1	0.0498 (9)	0.0514 (8)	0.0371 (8)	−0.0064 (7)	0.0025 (7)	−0.0051 (7)
O1	0.0670 (9)	0.0732 (9)	0.0412 (7)	−0.0227 (8)	0.0023 (6)	−0.0153 (7)
O2	0.0494 (7)	0.0600 (8)	0.0518 (7)	−0.0081 (6)	0.0091 (6)	0.0007 (6)
O3	0.0603 (8)	0.0719 (9)	0.0400 (7)	−0.0122 (7)	0.0081 (7)	−0.0087 (7)
S1	0.0594 (3)	0.0634 (3)	0.0428 (2)	−0.0111 (3)	0.0081 (2)	−0.0165 (2)

Geometric parameters (Å, º)

C1—N1	1.388 (2)	C10—C11	1.381 (3)
C1—C2	1.389 (3)	C10—H10	0.909 (19)
C1—C6	1.396 (3)	C11—O2	1.359 (2)
C2—C3	1.376 (3)	C11—C12	1.407 (3)
C2—H2	0.96 (2)	C12—O3	1.366 (2)
C3—C4	1.382 (3)	C12—C13	1.368 (2)
C3—H3	1.00 (3)	C13—H13	0.9300
C4—C5	1.374 (3)	C14—O3	1.407 (2)
C4—H4	0.97 (2)	C14—H14A	0.9600
C5—C6	1.396 (3)	C14—H14B	0.9600
C5—H5	0.97 (2)	C14—H14C	0.9600
C6—S1	1.7283 (19)	C15—O2	1.424 (2)
C7—N1	1.301 (2)	C15—H15A	0.9600
C7—C8	1.468 (2)	C15—H15C	0.9600
C7—S1	1.7583 (17)	C15—H15B	0.9600
C8—C9	1.389 (2)	C16—O1	1.411 (2)
C8—C13	1.408 (2)	C16—H16A	0.9600
C9—O1	1.358 (2)	C16—H16B	0.9600
C9—C10	1.397 (3)	C16—H16C	0.9600
N1—C1—C2	125.93 (18)	O2—C11—C12	115.28 (15)
N1—C1—C6	114.58 (16)	C10—C11—C12	120.20 (17)
C2—C1—C6	119.49 (18)	O3—C12—C13	125.58 (17)
C3—C2—C1	119.0 (2)	O3—C12—C11	115.25 (16)
C3—C2—H2	119.0 (14)	C13—C12—C11	119.17 (17)
C1—C2—H2	122.0 (14)	C12—C13—C8	121.80 (17)
C2—C3—C4	121.1 (2)	C12—C13—H13	119.1
C2—C3—H3	121.0 (15)	C8—C13—H13	119.1
C4—C3—H3	117.9 (14)	O3—C14—H14A	109.5
C5—C4—C3	121.3 (2)	O3—C14—H14B	109.5
C5—C4—H4	116.7 (14)	H14A—C14—H14B	109.5
C3—C4—H4	122.0 (14)	O3—C14—H14C	109.5
C4—C5—C6	117.8 (2)	H14A—C14—H14C	109.5
C4—C5—H5	123.6 (13)	H14B—C14—H14C	109.5
C6—C5—H5	118.6 (13)	O2—C15—H15A	109.5
C1—C6—C5	121.38 (18)	O2—C15—H15C	109.5
C1—C6—S1	110.02 (14)	H15A—C15—H15C	109.5
C5—C6—S1	128.60 (16)	O2—C15—H15B	109.5
N1—C7—C8	122.20 (15)	H15A—C15—H15B	109.5
N1—C7—S1	114.88 (14)	H15C—C15—H15B	109.5
C8—C7—S1	122.92 (13)	O1—C16—H16A	109.5
C9—C8—C13	118.13 (15)	O1—C16—H16B	109.5
C9—C8—C7	123.81 (15)	H16A—C16—H16B	109.5
C13—C8—C7	118.05 (15)	O1—C16—H16C	109.5
O1—C9—C8	116.58 (16)	H16A—C16—H16C	109.5
O1—C9—C10	122.66 (16)	H16B—C16—H16C	109.5
C8—C9—C10	120.76 (16)	C7—N1—C1	111.47 (15)
C11—C10—C9	119.88 (17)	C9—O1—C16	120.09 (15)
C11—C10—H10	122.8 (11)	C11—O2—C15	117.73 (15)
C9—C10—H10	117.2 (11)	C12—O3—C14	117.27 (15)
O2—C11—C10	124.53 (17)	C6—S1—C7	89.04 (9)
N1—C1—C2—C3	−179.2 (2)	O2—C11—C12—O3	−2.5 (2)
C6—C1—C2—C3	0.3 (3)	C10—C11—C12—O3	177.22 (16)
C1—C2—C3—C4	−0.2 (4)	O2—C11—C12—C13	177.91 (15)
C2—C3—C4—C5	−0.3 (4)	C10—C11—C12—C13	−2.4 (3)
C3—C4—C5—C6	0.6 (3)	O3—C12—C13—C8	−177.75 (17)
N1—C1—C6—C5	179.53 (18)	C11—C12—C13—C8	1.8 (3)
C2—C1—C6—C5	0.0 (3)	C9—C8—C13—C12	0.4 (3)
N1—C1—C6—S1	−0.5 (2)	C7—C8—C13—C12	−179.76 (16)
C2—C1—C6—S1	179.92 (15)	C8—C7—N1—C1	−179.19 (15)
C4—C5—C6—C1	−0.5 (3)	S1—C7—N1—C1	0.6 (2)
C4—C5—C6—S1	179.64 (17)	C2—C1—N1—C7	179.49 (18)
N1—C7—C8—C9	−175.75 (17)	C6—C1—N1—C7	0.0 (2)
S1—C7—C8—C9	4.5 (2)	C8—C9—O1—C16	−175.31 (17)
N1—C7—C8—C13	4.4 (2)	C10—C9—O1—C16	4.5 (3)
S1—C7—C8—C13	−175.33 (13)	C10—C11—O2—C15	−1.9 (3)
C13—C8—C9—O1	177.79 (16)	C12—C11—O2—C15	177.74 (15)
C7—C8—C9—O1	−2.1 (3)	C13—C12—O3—C14	−0.1 (3)
C13—C8—C9—C10	−2.0 (3)	C11—C12—O3—C14	−179.71 (17)
C7—C8—C9—C10	178.11 (16)	C1—C6—S1—C7	0.69 (14)
O1—C9—C10—C11	−178.34 (16)	C5—C6—S1—C7	−179.4 (2)
C8—C9—C10—C11	1.5 (3)	N1—C7—S1—C6	−0.75 (15)
C9—C10—C11—O2	−179.56 (16)	C8—C7—S1—C6	179.01 (15)
C9—C10—C11—C12	0.8 (3)