Quinoline

The crystal structure of quinoline, C₉H₇N, has been determined at 150 (2) K. In space group P2₁/c, the asymmetric unit comprises two independent mol­ecules. Molecules are linked via C—H...N interactions into two orthogonal sets of chains which are linked via an extensive network of edge-to-face C—H...π interactions.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.045
• wR factor = 0.124
• Data-to-parameter ratio = 13.3

checkCIF results

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ADDSYM reports no extra symmetry

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S1. Comment

Although the structure of naphthalene was one of the first determined by X-ray crystallography (Bragg, 1922), this is the first report of the structure of quinoline. This long delay may be attributed to the difficulty of obtaining a suitable single-crystal of quinoline. This work forms part of a study devoted to improving the techniques for determining the crystal structures of substances which are liquids at room temperature [see, for example, Bond et al. (2001)].

Quinoline, (I), crystallizes in the space group P2₁/c with the asymmetric unit comprising two independent molecules (denoted A and B, Fig. 1). Molecules of type A are linked via C—H···N interactions into chains running parallel to the c direction [H6A···N1Aⁱ = 2.89 (2) Å, C6A—H6A···N1Aⁱ = 141.1 (1)°; symmetry code: (i) x, 0.5 - y, 0.5 + z]. Molecules of type B are also linked via C—H···N interactions into chains running parallel to the b direction [H3B···N1Bⁱⁱ = 2.68 (2) Å, C3B—H3B···N1Bⁱⁱ = 171.1 (1)°; symmetry code: (ii) 2 - x, 0.5 + y, 1.5 - z]. Thus, there exists in (I) two orthogonal sets of C—H···N hydrogen-bonded chains. Between these chains, an extensive network of edge-to-face C—H···π interactions exists (Desiraju & Steiner, 1999). This network may be visualized most conveniently by considering that each edge of a molecule of (I) exposed in a type B chain is `capped' by a molecule of type A, and that these capped chains interlock to form two-dimensional layers parallel to (101) (Fig. 2). The layers may then be considered to stack in an ABCABC arrangement perpendicular to (101) with the C—H···N interactions between type A molecules linking the layers (Fig. 3).

S2. Experimental

The sample (98%) was obtained from the Aldrich Company and used without further purification. The crystal was grown with difficulty in a 0.3 mm glass capillary tube, obtained from the PANTAK company (PANTAK Company, Unit 30, The Robert Corl Industrial Estate, Britten Road, Reading, England), at 245 K (a temperature only slightly less than the melting point of the solid in the capillary tube). With the axis of the capillary parallel to the phi axis and horizontal on the instrument, the crystal was eventually grown by moving a plug of solid material up and down the tube (the movement being controlled with the standard Z (height) adjustment of the goniometer head). The goniometer head was a Nonius model 1516.916 X—Y—Z (Nonius BV, Delft, The Netherlands); this head is particularly well suited to the experiment described in this paper since it has an especially wide Z translation (8 mm). This method is effectively zone refinement, similar to the industrial methods used to grow large single crystals of silicon for the electronics industry. The fine temperature control necessary for the successful growth of the crystal was provided by an Oxford Cryosystems Cryostream (Oxford Cryosystems, Lower Road, Long Hanborough, Oxford, England).

S3. Refinement

The positions of all H atoms were allowed to refine independently. Pairs of chemically equivalent H atoms in the two independent molecules were assigned common, isotropic displacement parameters (7 variables in total).

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The asymmetric unit in (I) showing displacement ellipsoids at the 50% probability level (XP; Sheldrick, 1993). The two independent molecules adopt a geometry indicative of an edge-to-face C—H···π interaction.
	Fig. 2. Projection of (I) onto (101) showing type B molecules (coloured red) linked by C—H···N interactions into chains capped at each exposed edge by type A molecules (coloured green). Adjacent chains interlock to form two-dimensional sheets. Edge-to-face C—H···π interactions are shown as dotted lines only between the molecules at the edge of each chain (interactions between chains are not drawn for the purposes of clarity) (CAMERON; Watkin et al., 1996).
	Fig. 3. Projection of (I) onto (010) showing layers stacked in an ABCABC arrangement. C—H···N interactions between type A molecules link the layers and are shown as dotted lines (CAMERON; Watkin et al., 1996).

Quinoline

Crystal data

C9H7N	Dx = 1.244 Mg m^−3
Mr = 129.16	Melting point = 257–258 K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.7107 Å
a = 9.9226 (5) Å	Cell parameters from 6740 reflections
b = 10.8473 (7) Å	θ = 1.0–27.5°
c = 13.3665 (7) Å	µ = 0.07 mm^−1
β = 106.578 (3)°	T = 150 K
V = 1378.88 (13) Å^3	Cylinder, colourless
Z = 8	0.26 mm (radius)
F(000) = 544

Data collection

Nonius KappaCCD diffractometer	Rint = 0.018
Radiation source: fine-focus sealed tube	θmax = 27.4°, θmin = 3.6°
Thin–slice ω and ϕ scans	h = −12→12
4851 measured reflections	k = −12→14
3055 independent reflections	l = −17→17
2337 reflections with I > 2σ(I)

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)] = 0.045	Hydrogen site location: difference Fourier map
wR(F^2) = 0.124	All H-atom parameters refined
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0556P)^2 + 0.2728P] where P = (Fo^2 + 2Fc^2)/3
3055 reflections	(Δ/σ)max = 0.002
230 parameters	Δρmax = 0.18 e Å^−3
0 restraints	Δρmin = −0.18 e Å^−3

Special details

Experimental. Grown in a 0.30 mm glass capillary tube at 245 K

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
N1A	0.65225 (13)	0.07533 (12)	0.23904 (9)	0.0452 (3)
C2A	0.54448 (17)	−0.00110 (16)	0.21851 (13)	0.0549 (4)
H2A	0.531 (2)	−0.0560 (18)	0.1551 (15)	0.071 (4)*
C3A	0.45114 (17)	−0.01252 (16)	0.27924 (15)	0.0582 (5)
H3A	0.375 (2)	−0.0737 (17)	0.2596 (13)	0.064 (4)*
C4A	0.47055 (15)	0.05872 (15)	0.36503 (14)	0.0499 (4)
H4A	0.4112 (18)	0.0555 (15)	0.4118 (12)	0.052 (3)*
C5A	0.61552 (18)	0.21815 (14)	0.48250 (12)	0.0466 (4)
H5A	0.5547 (17)	0.2137 (15)	0.5255 (13)	0.053 (3)*
C6A	0.7300 (2)	0.29307 (14)	0.50649 (13)	0.0521 (4)
H6A	0.7558 (19)	0.3422 (17)	0.5694 (14)	0.063 (4)*
C7A	0.81915 (18)	0.29743 (13)	0.44123 (13)	0.0492 (4)
H7A	0.9067 (19)	0.3531 (17)	0.4611 (13)	0.063 (4)*
C8A	0.79123 (15)	0.22698 (13)	0.35304 (12)	0.0415 (3)
H8A	0.8508 (18)	0.2290 (15)	0.3062 (13)	0.057 (3)*
C9A	0.67380 (13)	0.14730 (12)	0.32681 (10)	0.0346 (3)
C10A	0.58453 (14)	0.14235 (12)	0.39252 (10)	0.0373 (3)
N1B	0.89070 (14)	−0.18868 (13)	0.73237 (9)	0.0483 (3)
C2B	0.93813 (17)	−0.07581 (17)	0.75730 (12)	0.0531 (4)
H2B	0.974 (2)	−0.0584 (17)	0.8338 (15)	0.071 (4)*
C3B	0.93974 (15)	0.01761 (15)	0.68472 (12)	0.0473 (4)
H3B	0.9746 (19)	0.0981 (18)	0.7078 (13)	0.064 (4)*
C4B	0.89030 (14)	−0.00839 (12)	0.58122 (11)	0.0372 (3)
H4B	0.8869 (17)	0.0548 (15)	0.5285 (12)	0.052 (3)*
C5B	0.78315 (14)	−0.16227 (13)	0.44397 (10)	0.0380 (3)
H5B	0.7828 (17)	−0.1016 (15)	0.3884 (12)	0.053 (3)*
C6B	0.72953 (16)	−0.27704 (14)	0.41768 (12)	0.0471 (4)
H6B	0.6889 (18)	−0.3002 (16)	0.3406 (14)	0.063 (4)*
C7B	0.72999 (17)	−0.36330 (14)	0.49616 (14)	0.0511 (4)
H7B	0.6901 (18)	−0.4468 (18)	0.4770 (13)	0.063 (4)*
C8B	0.78385 (15)	−0.33428 (13)	0.59868 (13)	0.0456 (4)
H8B	0.7839 (18)	−0.3935 (16)	0.6560 (13)	0.057 (3)*
C9B	0.83913 (13)	−0.21504 (12)	0.62842 (10)	0.0343 (3)
C10B	0.83788 (12)	−0.12738 (11)	0.54945 (9)	0.0305 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1A	0.0450 (7)	0.0494 (7)	0.0385 (6)	0.0108 (6)	0.0074 (5)	−0.0014 (5)
C2A	0.0465 (9)	0.0527 (9)	0.0531 (9)	0.0092 (8)	−0.0060 (7)	−0.0065 (7)
C3A	0.0347 (8)	0.0469 (9)	0.0820 (13)	0.0006 (7)	−0.0012 (8)	0.0064 (8)
C4A	0.0323 (7)	0.0479 (9)	0.0720 (11)	0.0100 (6)	0.0189 (7)	0.0192 (8)
C5A	0.0596 (9)	0.0416 (8)	0.0460 (8)	0.0201 (7)	0.0270 (7)	0.0106 (6)
C6A	0.0773 (11)	0.0329 (7)	0.0430 (8)	0.0139 (8)	0.0122 (8)	0.0001 (6)
C7A	0.0552 (9)	0.0322 (7)	0.0554 (9)	−0.0023 (7)	0.0079 (7)	0.0048 (6)
C8A	0.0404 (8)	0.0386 (7)	0.0483 (8)	0.0040 (6)	0.0169 (6)	0.0096 (6)
C9A	0.0339 (7)	0.0338 (7)	0.0369 (7)	0.0090 (5)	0.0115 (5)	0.0065 (5)
C10A	0.0360 (7)	0.0347 (7)	0.0435 (7)	0.0127 (5)	0.0154 (6)	0.0118 (6)
N1B	0.0489 (7)	0.0591 (8)	0.0378 (6)	0.0067 (6)	0.0137 (5)	0.0083 (6)
C2B	0.0507 (9)	0.0698 (11)	0.0361 (8)	0.0105 (8)	0.0078 (6)	−0.0066 (7)
C3B	0.0426 (8)	0.0413 (8)	0.0558 (9)	0.0019 (6)	0.0103 (7)	−0.0126 (7)
C4B	0.0339 (7)	0.0319 (7)	0.0470 (8)	0.0036 (5)	0.0138 (6)	0.0031 (6)
C5B	0.0392 (7)	0.0401 (7)	0.0365 (7)	0.0032 (6)	0.0137 (6)	0.0036 (6)
C6B	0.0476 (8)	0.0463 (8)	0.0462 (9)	0.0012 (7)	0.0117 (7)	−0.0083 (7)
C7B	0.0464 (8)	0.0328 (7)	0.0700 (11)	−0.0008 (7)	0.0098 (7)	−0.0016 (7)
C8B	0.0399 (8)	0.0355 (7)	0.0614 (9)	0.0015 (6)	0.0144 (7)	0.0172 (7)
C9B	0.0297 (6)	0.0369 (7)	0.0380 (7)	0.0069 (5)	0.0123 (5)	0.0093 (5)
C10B	0.0277 (6)	0.0297 (6)	0.0365 (6)	0.0049 (5)	0.0132 (5)	0.0037 (5)

Geometric parameters (Å, º)

N1A—C2A	1.319 (2)	N1B—C2B	1.320 (2)
N1A—C9A	1.3742 (17)	N1B—C9B	1.3670 (18)
C2A—C3A	1.400 (3)	C2B—C3B	1.406 (2)
C2A—H2A	1.01 (2)	C2B—H2B	1.00 (2)
C3A—C4A	1.350 (3)	C3B—C4B	1.359 (2)
C3A—H3A	0.98 (2)	C3B—H3B	0.96 (2)
C4A—C10A	1.414 (2)	C4B—C10B	1.4109 (18)
C4A—H4A	0.97 (2)	C4B—H4B	0.98 (2)
C5A—C6A	1.358 (2)	C5B—C6B	1.360 (2)
C5A—C10A	1.416 (2)	C5B—C10B	1.4103 (18)
C5A—H5A	0.95 (2)	C5B—H5B	0.99 (2)
C6A—C7A	1.410 (2)	C6B—C7B	1.405 (2)
C6A—H6A	0.97 (2)	C6B—H6B	1.02 (2)
C7A—C8A	1.365 (2)	C7B—C8B	1.358 (2)
C7A—H7A	1.03 (2)	C7B—H7B	0.99 (2)
C8A—C9A	1.412 (2)	C8B—C9B	1.417 (2)
C8A—H8A	0.98 (2)	C8B—H8B	1.00 (2)
C9A—C10A	1.4152 (18)	C9B—C10B	1.4181 (17)
C2A—N1A—C9A	117.02 (13)	C2B—N1B—C9B	116.98 (13)
N1A—C2A—C3A	124.48 (16)	N1B—C2B—C3B	124.60 (14)
N1A—C2A—H2A	116.6 (11)	N1B—C2B—H2B	115.5 (11)
C3A—C2A—H2A	118.9 (11)	C3B—C2B—H2B	119.9 (11)
C4A—C3A—C2A	118.95 (16)	C4B—C3B—C2B	118.74 (14)
C4A—C3A—H3A	121.7 (10)	C4B—C3B—H3B	120.7 (10)
C2A—C3A—H3A	119.4 (10)	C2B—C3B—H3B	120.6 (10)
C3A—C4A—C10A	119.83 (15)	C3B—C4B—C10B	119.43 (13)
C3A—C4A—H4A	124.0 (10)	C3B—C4B—H4B	121.1 (9)
C10A—C4A—H4A	116.2 (10)	C10B—C4B—H4B	119.4 (9)
C6A—C5A—C10A	120.80 (14)	C6B—C5B—C10B	120.97 (13)
C6A—C5A—H5A	121.5 (10)	C6B—C5B—H5B	119.7 (9)
C10A—C5A—H5A	117.7 (10)	C10B—C5B—H5B	119.3 (9)
C5A—C6A—C7A	120.28 (15)	C5B—C6B—C7B	119.94 (14)
C5A—C6A—H6A	122.1 (11)	C5B—C6B—H6B	119.8 (10)
C7A—C6A—H6A	117.6 (11)	C7B—C6B—H6B	120.3 (10)
C8A—C7A—C6A	120.47 (15)	C8B—C7B—C6B	121.04 (14)
C8A—C7A—H7A	120.0 (10)	C8B—C7B—H7B	119.0 (10)
C6A—C7A—H7A	119.5 (10)	C6B—C7B—H7B	119.9 (10)
C7A—C8A—C9A	120.44 (14)	C7B—C8B—C9B	120.26 (13)
C7A—C8A—H8A	122.0 (10)	C7B—C8B—H8B	122.5 (10)
C9A—C8A—H8A	117.6 (10)	C9B—C8B—H8B	117.2 (10)
N1A—C9A—C8A	118.42 (12)	N1B—C9B—C8B	118.61 (12)
N1A—C9A—C10A	122.40 (12)	N1B—C9B—C10B	122.52 (12)
C8A—C9A—C10A	119.17 (13)	C8B—C9B—C10B	118.87 (12)
C4A—C10A—C9A	117.32 (13)	C5B—C10B—C4B	123.38 (12)
C4A—C10A—C5A	123.83 (13)	C5B—C10B—C9B	118.90 (12)
C9A—C10A—C5A	118.83 (13)	C4B—C10B—C9B	117.72 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3B—H3B···N1B^i	0.96 (2)	2.68 (2)	3.626 (2)	171.1 (1)
C6A—H6A···N1A^ii	0.97 (2)	2.89 (2)	3.696 (2)	141.1 (1)

Symmetry codes: (i) −x+2, y+1/2, −z+3/2; (ii) x, −y+1/2, z+1/2.