Ethyl 4-methyl-9H-carbazole-3-carboxyl­ate

The title compound, C₁₆H₁₅NO₂, consists of a carbazole skeleton with carboxy­ethyl and methyl groups at positions 3 and 4, respectively. Molecules are linked about inversion centres by N—H...O hydrogen bonds [N...O 2.897 (3) Å] to form centrosymmetric dimers.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.065
• wR factor = 0.200
• Data-to-parameter ratio = 12.2

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level A:



DIFF_012  Alert A _diffrn_reflns_av_R_equivalents is missing
          R factor for symmetry-equivalent intensities.
          The following tests will not be performed
          RINTA


 Alert Level C:



PLAT_353  Alert C Long  N-H Bond (0.87A)     N(9)   -   H(9)   =       1.02 Ang.


 1 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

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Computing details

Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999).

(I)

Crystal data

C16H15NO2	F(000) = 536
Mr = 253.29	Dx = 1.308 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 7.2919 (10) Å	θ = 10–18°
b = 9.0198 (10) Å	µ = 0.69 mm^−1
c = 19.583 (2) Å	T = 293 K
β = 92.798 (9)°	Rod-shaped, colorless
V = 1286.4 (3) Å^3	0.3 × 0.25 × 0.2 mm
Z = 4

Data collection

Enraf-Nonius CAD-4 diffractometer	1320 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	θmax = 74.1°, θmin = 4.5°
Graphite monochromator	h = 0→9
non–profiled ω scans	k = −11→0
Absorption correction: ψ scan (North et al., 1968)	l = −24→24
Tmin = 0.812, Tmax = 0.871	3 standard reflections every 120 min
2612 measured reflections	intensity decay: 1%
2612 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.065	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.200	H atoms treated by a mixture of independent and constrained refinement
S = 0.93	w = 1/[σ^2(Fo^2) + (0.1415P)^2] where P = (Fo^2 + 2Fc^2)/3
2141 reflections	(Δ/σ)max < 0.001
176 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

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
O1	0.2670 (4)	1.2819 (2)	0.54120 (11)	0.0800 (7)
O2	0.3314 (3)	1.1885 (2)	0.64427 (10)	0.0661 (6)
N9	0.2240 (4)	0.5832 (3)	0.49170 (13)	0.0638 (7)
C1	0.2754 (4)	0.7581 (3)	0.58915 (14)	0.0615 (8)
C2	0.2861 (4)	0.9047 (3)	0.60479 (14)	0.0586 (7)
C3	0.2713 (4)	1.0179 (3)	0.55547 (13)	0.0506 (7)
C4	0.2386 (4)	0.9799 (3)	0.48535 (13)	0.0500 (7)
C4a	0.2233 (4)	0.8299 (3)	0.46895 (14)	0.0506 (6)
C5	0.1557 (4)	0.7901 (3)	0.33626 (14)	0.0599 (7)
C5a	0.1891 (4)	0.7496 (3)	0.40526 (13)	0.0524 (7)
C6	0.1303 (5)	0.6804 (4)	0.28794 (16)	0.0680 (9)
C7	0.1351 (5)	0.5328 (4)	0.30515 (17)	0.0726 (9)
C8	0.1660 (5)	0.4892 (4)	0.37250 (18)	0.0743 (9)
C8a	0.1912 (4)	0.5993 (3)	0.42120 (15)	0.0590 (7)
C9a	0.2409 (4)	0.7202 (3)	0.52026 (14)	0.0543 (7)
C10	0.2259 (5)	1.0929 (3)	0.42927 (15)	0.0689 (9)
C11	0.2863 (4)	1.1738 (3)	0.57691 (14)	0.0533 (7)
C12	0.3514 (5)	1.3378 (4)	0.66897 (16)	0.0703 (9)
C13	0.3834 (6)	1.3309 (5)	0.74579 (18)	0.0901 (12)
H1	0.2903	0.6857	0.6228	0.074*
H2	0.3042	0.9315	0.6505	0.070*
H5	0.1510	0.8895	0.3236	0.072*
H6	0.1093	0.7069	0.2423	0.082*
H7	0.1174	0.4614	0.2712	0.087*
H8	0.1696	0.3894	0.3846	0.089*
H9	0.233 (5)	0.481 (4)	0.5144 (17)	0.077 (10)*
H10A	0.2025	1.0440	0.3862	0.103*
H10B	0.3395	1.1466	0.4284	0.103*
H10C	0.1276	1.1606	0.4373	0.103*
H12A	0.2413	1.3944	0.6572	0.084*
H12B	0.4544	1.3855	0.6485	0.084*
H13A	0.3971	1.4296	0.7637	0.135*
H13B	0.4929	1.2751	0.7569	0.135*
H13C	0.2806	1.2838	0.7656	0.135*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N9	0.0836 (19)	0.0455 (15)	0.0619 (14)	−0.0007 (12)	−0.0018 (13)	0.0082 (12)
O1	0.125 (2)	0.0477 (13)	0.0665 (13)	0.0034 (12)	−0.0003 (13)	0.0067 (10)
O2	0.0803 (15)	0.0601 (13)	0.0572 (11)	−0.0012 (10)	−0.0028 (10)	−0.0044 (10)
C1	0.077 (2)	0.0514 (17)	0.0547 (15)	0.0007 (14)	−0.0062 (14)	0.0132 (13)
C2	0.0689 (19)	0.0569 (18)	0.0497 (14)	−0.0026 (13)	−0.0004 (13)	0.0061 (13)
C3	0.0531 (15)	0.0458 (15)	0.0525 (14)	0.0007 (11)	−0.0024 (12)	0.0044 (12)
C4	0.0498 (15)	0.0490 (16)	0.0513 (14)	0.0023 (11)	0.0046 (12)	0.0061 (12)
C4a	0.0521 (15)	0.0448 (15)	0.0551 (14)	−0.0008 (11)	0.0048 (12)	0.0060 (11)
C5	0.0657 (18)	0.0557 (17)	0.0584 (16)	0.0011 (13)	0.0050 (13)	0.0072 (14)
C5a	0.0542 (16)	0.0476 (15)	0.0556 (15)	0.0007 (11)	0.0033 (12)	0.0022 (12)
C6	0.077 (2)	0.066 (2)	0.0603 (17)	0.0014 (16)	−0.0011 (15)	−0.0029 (15)
C7	0.079 (2)	0.067 (2)	0.0714 (19)	0.0025 (16)	−0.0042 (17)	−0.0124 (17)
C8	0.093 (2)	0.0515 (18)	0.077 (2)	0.0028 (16)	−0.0017 (19)	0.0031 (15)
C8a	0.071 (2)	0.0461 (16)	0.0598 (16)	0.0012 (13)	0.0016 (14)	0.0045 (13)
C9a	0.0602 (17)	0.0428 (15)	0.0597 (15)	−0.0012 (12)	0.0022 (12)	0.0073 (12)
C10	0.099 (2)	0.0503 (17)	0.0572 (16)	−0.0033 (16)	0.0044 (16)	0.0071 (14)
C11	0.0573 (17)	0.0491 (16)	0.0534 (15)	−0.0006 (12)	0.0004 (12)	0.0016 (12)
C12	0.078 (2)	0.063 (2)	0.0705 (19)	−0.0072 (15)	0.0084 (16)	−0.0145 (16)
C13	0.099 (3)	0.099 (3)	0.071 (2)	−0.013 (2)	−0.001 (2)	−0.024 (2)

Geometric parameters (Å, º)

C12—O2	1.436 (4)	C3—C2	1.406 (4)
C12—C13	1.512 (5)	C2—C1	1.359 (4)
C12—H12A	0.9700	C2—H2	0.9300
C12—H12B	0.9700	C9a—N9	1.360 (4)
C13—H13A	0.9600	C9a—C1	1.402 (4)
C13—H13B	0.9600	C5a—C5	1.409 (4)
C13—H13C	0.9600	C5—C6	1.376 (4)
C4a—C4	1.394 (4)	C5—H5	0.9300
C4a—C9a	1.411 (4)	N9—H9	1.02 (4)
C4a—C5a	1.453 (4)	C1—H1	0.9300
O1—C11	1.204 (3)	C6—C7	1.374 (5)
O2—C11	1.350 (3)	C6—H6	0.9300
C8a—C8	1.383 (4)	C8—C7	1.384 (5)
C8a—C5a	1.391 (4)	C8—H8	0.9300
C8a—N9	1.397 (4)	C7—H7	0.9300
C4—C3	1.424 (4)	C10—H10A	0.9600
C4—C10	1.498 (4)	C10—H10B	0.9600
C11—C3	1.470 (4)	C10—H10C	0.9600
O2—C12—C13	107.7 (3)	N9—C9a—C1	128.7 (3)
O2—C12—H12A	110.2	N9—C9a—C4a	109.9 (2)
C13—C12—H12A	110.2	C1—C9a—C4a	121.3 (3)
O2—C12—H12B	110.2	C8a—C5a—C5	117.9 (3)
C13—C12—H12B	110.2	C8a—C5a—C4a	107.1 (2)
H12A—C12—H12B	108.5	C5—C5a—C4a	135.1 (3)
C12—C13—H13A	109.5	C6—C5—C5a	118.9 (3)
C12—C13—H13B	109.5	C6—C5—H5	120.5
H13A—C13—H13B	109.5	C5a—C5—H5	120.5
C12—C13—H13C	109.5	C9a—N9—C8a	108.6 (2)
H13A—C13—H13C	109.5	C9a—N9—H9	129.6 (19)
H13B—C13—H13C	109.5	C8a—N9—H9	121.8 (19)
C4—C4a—C9a	120.8 (3)	C2—C1—C9a	117.4 (3)
C4—C4a—C5a	133.6 (2)	C2—C1—H1	121.3
C9A—C4a—C5a	105.5 (2)	C9a—C1—H1	121.3
C11—O2—C12	115.9 (2)	C7—C6—C5	121.9 (3)
C8—C8a—C5a	123.1 (3)	C7—C6—H6	119.1
C8—C8a—N9	128.1 (3)	C5—C6—H6	119.1
C5a—C8a—N9	108.8 (2)	C8a—C8—C7	117.6 (3)
C4a—C4—C3	117.6 (2)	C8a—C8—H8	121.2
C4a—C4—C10	119.4 (2)	C7—C8—H8	121.2
C3—C4—C10	123.0 (3)	C6—C7—C8	120.7 (3)
O1—C11—O2	120.3 (3)	C6—C7—H7	119.7
O1—C11—C3	127.1 (3)	C8—C7—H7	119.7
O2—C11—C3	112.6 (2)	C4—C10—H10A	109.5
C2—C3—C4	119.4 (3)	C4—C10—H10B	109.5
C2—C3—C11	119.8 (3)	H10A—C10—H10B	109.5
C4—C3—C11	120.8 (2)	C4—C10—H10C	109.5
C1—C2—C3	123.4 (3)	H10A—C10—H10C	109.5
C1—C2—H2	118.3	H10B—C10—H10C	109.5
C3—C2—H2	118.3
C13—C12—O2—C11	174.6 (3)	N9—C8a—C5a—C5	−179.3 (3)
C9a—C4a—C4—C3	−0.4 (4)	C8—C8a—C5a—C4a	−179.0 (3)
C5a—C4a—C4—C3	179.2 (3)	N9—C8a—C5a—C4a	0.3 (3)
C9a—C4a—C4—C10	177.8 (3)	C4—C4a—C5a—C8a	179.4 (3)
C5a—C4a—C4—C10	−2.6 (5)	C9a—C4a—C5a—C8a	−1.0 (3)
C12—O2—C11—O1	0.8 (4)	C4—C4a—C5a—C5	−1.1 (6)
C12—O2—C11—C3	179.1 (2)	C9a—C4a—C5a—C5	178.5 (3)
C4a—C4—C3—C2	−0.2 (4)	C8a—C5a—C5—C6	−1.2 (4)
C10—C4—C3—C2	−178.3 (3)	C4a—C5a—C5—C6	179.3 (3)
C4a—C4—C3—C11	−179.1 (3)	C1—C9A—N9—C8a	−179.6 (3)
C10—C4—C3—C11	2.8 (4)	C4a—C9a—N9—C8a	−1.2 (3)
O1—C11—C3—C2	−175.8 (3)	C8—C8a—N9—C9a	179.8 (3)
O2—C11—C3—C2	6.0 (4)	C5a—C8a—N9—C9a	0.5 (3)
O1—C11—C3—C4	3.0 (5)	C3—C2—C1—C9a	−2.5 (5)
O2—C11—C3—C4	−175.2 (2)	N9—C9a—C1—C2	180.0 (3)
C4—C3—C2—C1	1.7 (5)	C4a—C9a—C1—C2	1.8 (4)
C11—C3—C2—C1	−179.4 (3)	C5a—C5—C6—C7	0.5 (5)
C4—C4a—C9a—N9	−178.9 (2)	C5a—C8a—C8—C7	−0.8 (5)
C5a—C4a—C9a—N9	1.4 (3)	N9—C8a—C8—C7	180.0 (3)
C4—C4a—C9a—C1	−0.4 (4)	C5—C6—C7—C8	0.0 (5)
C5a—C4a—C9a—C1	179.9 (3)	C8a—C8—C7—C6	0.1 (5)
C8—C8a—C5a—C5	1.4 (5)