Bis(1,2,3,4-tetra­hydro­quinolin-6-yl)methane

Abstract

The asymmetric unit of the title compound, C₁₉H₂₂N₂, contains one half-mol­ecule. The 1,2,3,4-tetra­hydro­quinoline units are linked by a methyl­ene bridge, which lies on a twofold rotation axis. The non-aromatic ring adopts a flattened-boat conformation. The dihedral angle between the two symmetry-related benzene rings is 64.03 (7)°.

Related literature

For general background, see: Xiao et al. (2008a ▶,b ▶,c ▶); Xiao et al. (2007a ▶,b ▶); Xue et al. (2007 ▶). For ring conformation puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

• C₁₉H₂₂N₂

• M _r = 278.39

• Orthorhombic,

• a = 17.515 (3) Å

• b = 29.660 (4) Å

• c = 5.7678 (8) Å

• V = 2996.2 (8) ų

• Z = 8

• Mo Kα radiation

• μ = 0.07 mm⁻¹

• T = 292 (2) K

• 0.30 × 0.20 × 0.20 mm

Data collection

• Enraf–Nonius CAD-4 diffractometer

• Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.979, T _max = 0.986

• 4545 measured reflections

• 814 independent reflections

• 773 reflections with I > 2σ(I)

• R _int = 0.073

Refinement

• R[F ² > 2σ(F ²)] = 0.048

• wR(F ²) = 0.138

• S = 1.07

• 814 reflections

• 100 parameters

• 2 restraints

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.28 e Å⁻³

• Δρ_min = −0.21 e Å⁻³

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Comment

Nitrogen heterocyclic compounds show diverse biological activities such as antiproliferative (Xiao et al., 2008a,b), antibacterial (Xiao et al., 2007a; Xue et al., 2007; Xiao et al., 2008c), and urease inhibitory (Xiao et al., 2007b) activities. The title compound is a heterocyclic compound, which may be used for screening the biological activities. We report herein its crystal structure.

The asymmetric unit of the title compound (Fig. 1) contains one-half molecule. 1,2,3,4-Tetrahydroquinoline moieties are joined by a methylene bridge. Ring A (N1/C2-C4/C9/C10) adopts flattened-boat [φ = 126.28 (2)°, θ = 26.77 (3)°] conformation, having total puckering amplitude, Q_T, of 0.448 (3) Å (Cremer & Pople, 1975). The dihedral angle between the two symmetry related phenyl rings is 64.03 (7)°.

Experimental

Heating of 4,4'-methylenedibenzenamine (2 g), bis(4-nitrophenyl)methane (0.5 g), H₃AsO₄ (1.5 g), concentrated H₂SO₄ (3 ml), and glycerol (8.6 ml) at 413 K for 5 h, addition of water, removal of resinous matter, making alkalization with NaOH, taking up in ether, dehydration with K₂CO₃, and recrystallization of the residue from alcohol gives diquinolin-6-ylmethane. The resulting product (1 g) was subsequently heated with Sn (5.5 g) and HCl (22 ml, 32%) in a water bath for 8 h, addition of water, precipitation of the Sn as Sn(OH)₂ by NaOH, taking up in ether, and drying with K₂CO₃, gives the title compound (yield; 0.9 g), which was recrystallized from petroleum ether-ethyl acetate to give colorless prisms.

Refinement

H1 atom (for bridging CH₂) was located in difference syntheses and refined isotropically [C-H = 0.97 (2) Å and U_iso(H) = 0.067 (10) Ų]. The remaining H atoms were positioned geometrically, with N-H = 0.86 Å (for NH) and C-H = 0.93 and 0.97 Å for aromatic and methylene H, respectively, and constrained to ride on their parent atoms with U_iso(H) = 1.2U_eq(C).

Figures

Fig. 1.

The molecular structure of the title molecule, with the atom-numbering scheme [symmetry code: (a) -x, 1 - y, z].

Crystal data

C19H22N2	F000 = 1200
Mr = 278.39	Dx = 1.234 Mg m−3
Orthorhombic, Fdd2	Mo Kα radiation λ = 0.71073 Å
Hall symbol: F 2 -2d	Cell parameters from 1297 reflections
a = 17.515 (3) Å	θ = 2.9–25.2º
b = 29.660 (4) Å	µ = 0.07 mm−1
c = 5.7678 (8) Å	T = 292 (2) K
V = 2996.2 (8) Å3	Prism, colorless
Z = 8	0.30 × 0.20 × 0.20 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	814 independent reflections
Radiation source: fine-focus sealed tube	773 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.073
T = 292(2) K	θmax = 26.0º
ω/2θ scans	θmin = 2.7º
Absorption correction: ψ scan(North et al., 1968)	h = −21→21
Tmin = 0.979, Tmax = 0.986	k = −36→32
4545 measured reflections	l = −7→6

Refinement

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)] = 0.048	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.138	w = 1/[σ2(Fo2) + (0.0996P)2 + 0.9957P] where P = (Fo2 + 2Fc2)/3
S = 1.08	(Δ/σ)max < 0.001
814 reflections	Δρmax = 0.28 e Å−3
100 parameters	Δρmin = −0.21 e Å−3
2 restraints	Extinction correction: none
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
N1	0.26094 (12)	0.44383 (8)	1.0848 (5)	0.0605 (7)
H11A	0.2700	0.4566	1.2159	0.073*
C1	0.0000	0.5000	0.5624 (6)	0.0519 (9)
H1	0.0128 (16)	0.5254 (7)	0.464 (5)	0.067 (10)*
C2	0.31123 (16)	0.40914 (9)	1.0048 (7)	0.0637 (9)
H2A	0.3360	0.3951	1.1368	0.076*
H2B	0.3505	0.4224	0.9080	0.076*
C3	0.27005 (17)	0.37452 (10)	0.8715 (8)	0.0662 (9)
H3A	0.2357	0.3584	0.9740	0.079*
H3B	0.3064	0.3530	0.8094	0.079*
C4	0.22470 (16)	0.39493 (9)	0.6743 (6)	0.0579 (8)
H4A	0.2595	0.4045	0.5530	0.070*
H4B	0.1911	0.3722	0.6097	0.070*
C5	0.11375 (13)	0.44942 (7)	0.6314 (5)	0.0415 (6)
H5	0.1004	0.4345	0.4954	0.050*
C6	0.06877 (12)	0.48523 (8)	0.7038 (5)	0.0407 (6)
C7	0.09023 (12)	0.50718 (8)	0.9058 (5)	0.0434 (6)
H7	0.0615	0.5315	0.9581	0.052*
C8	0.15365 (13)	0.49360 (8)	1.0313 (5)	0.0435 (6)
H8	0.1667	0.5088	1.1667	0.052*
C9	0.19817 (12)	0.45735 (7)	0.9568 (5)	0.0384 (5)
C10	0.17797 (12)	0.43464 (7)	0.7524 (5)	0.0390 (6)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N1	0.0578 (13)	0.0610 (13)	0.0628 (17)	0.0115 (10)	−0.0273 (12)	−0.0153 (13)
C1	0.0451 (19)	0.068 (2)	0.042 (2)	0.0156 (17)	0.000	0.000
C2	0.0537 (15)	0.0635 (16)	0.074 (2)	0.0170 (11)	−0.0201 (16)	0.0025 (16)
C3	0.0623 (16)	0.0582 (15)	0.078 (2)	0.0198 (12)	−0.0097 (17)	−0.0042 (16)
C4	0.0622 (16)	0.0558 (14)	0.0558 (18)	0.0202 (12)	−0.0111 (15)	−0.0126 (14)
C5	0.0420 (12)	0.0442 (11)	0.0384 (13)	0.0016 (9)	−0.0014 (11)	−0.0069 (10)
C6	0.0324 (10)	0.0460 (10)	0.0437 (13)	0.0024 (8)	0.0016 (10)	0.0000 (11)
C7	0.0383 (11)	0.0416 (11)	0.0504 (15)	0.0045 (9)	0.0061 (10)	−0.0052 (11)
C8	0.0440 (12)	0.0432 (11)	0.0433 (14)	−0.0040 (9)	−0.0018 (11)	−0.0113 (11)
C9	0.0345 (11)	0.0392 (10)	0.0416 (13)	−0.0032 (8)	−0.0034 (10)	0.0013 (10)
C10	0.0398 (11)	0.0375 (10)	0.0398 (12)	0.0008 (8)	−0.0007 (10)	−0.0036 (11)

Geometric parameters (Å, °)

N1—C2	1.431 (3)	C4—H4B	0.9700
N1—H11A	0.8600	C5—C6	1.387 (3)
C1—C6	1.519 (3)	C5—C10	1.394 (3)
C1—C6i	1.519 (3)	C5—H5	0.9300
C1—H1	0.97 (2)	C7—C6	1.386 (4)
C2—C3	1.472 (4)	C7—H7	0.9300
C2—H2A	0.9700	C8—C7	1.386 (3)
C2—H2B	0.9700	C8—H8	0.9300
C3—H3A	0.9700	C9—N1	1.384 (3)
C3—H3B	0.9700	C9—C8	1.396 (3)
C4—C3	1.514 (4)	C9—C10	1.403 (4)
C4—H4A	0.9700	C10—C4	1.503 (3)
C9—N1—C2	121.7 (3)	C10—C4—H4B	109.2
C9—N1—H11A	119.2	C3—C4—H4B	109.2
C2—N1—H11A	119.2	H4A—C4—H4B	107.9
C6—C1—C6i	115.1 (3)	C6—C5—C10	123.3 (2)
C6—C1—H1	110.8 (18)	C6—C5—H5	118.4
C6i—C1—H1	105.9 (19)	C10—C5—H5	118.4
N1—C2—C3	111.6 (2)	C7—C6—C5	117.3 (2)
N1—C2—H2A	109.3	C7—C6—C1	122.0 (2)
C3—C2—H2A	109.3	C5—C6—C1	120.6 (2)
N1—C2—H2B	109.3	C8—C7—C6	121.3 (2)
C3—C2—H2B	109.3	C8—C7—H7	119.3
H2A—C2—H2B	108.0	C6—C7—H7	119.3
C2—C3—C4	111.8 (2)	C7—C8—C9	120.7 (2)
C2—C3—H3A	109.3	C7—C8—H8	119.6
C4—C3—H3A	109.3	C9—C8—H8	119.6
C2—C3—H3B	109.3	N1—C9—C8	120.2 (2)
C4—C3—H3B	109.3	N1—C9—C10	120.6 (2)
H3A—C3—H3B	107.9	C8—C9—C10	119.2 (2)
C10—C4—C3	112.0 (2)	C5—C10—C9	118.2 (2)
C10—C4—H4A	109.2	C5—C10—C4	122.4 (2)
C3—C4—H4A	109.2	C9—C10—C4	119.4 (2)
C9—N1—C2—C3	−33.5 (4)	C9—C8—C7—C6	0.3 (4)
C6i—C1—C6—C7	−39.05 (19)	C8—C9—N1—C2	−175.1 (2)
C6i—C1—C6—C5	142.3 (3)	C10—C9—N1—C2	5.6 (4)
N1—C2—C3—C4	54.2 (4)	N1—C9—C8—C7	−179.4 (2)
C10—C4—C3—C2	−48.1 (4)	C10—C9—C8—C7	0.0 (4)
C10—C5—C6—C7	0.6 (4)	N1—C9—C10—C5	179.4 (2)
C10—C5—C6—C1	179.3 (2)	C8—C9—C10—C5	0.0 (3)
C6—C5—C10—C9	−0.3 (4)	N1—C9—C10—C4	0.7 (4)
C6—C5—C10—C4	178.3 (2)	C8—C9—C10—C4	−178.6 (2)
C8—C7—C6—C5	−0.6 (4)	C5—C10—C4—C3	−157.7 (2)
C8—C7—C6—C1	−179.2 (2)	C9—C10—C4—C3	20.9 (4)

Symmetry codes: (i) −x, −y+1, z.