Redetermination of 3-methyl-isoquinoline at 150 K.

The structure of the title compound, C(19)H(9)O, has been redetermined at 150 K. The redetermination is of significantly higher precision than a previous room-temperature structure [Ribar et al. (1974 ▶). Cryst. Struct. Commun.3, 323-325]. The C-N bond lengths for this redetermination are much closer to those observed in comparable structures, and the orientation of the methyl group with respect to the isoquinoline plane is clarified. Inter-molecular weak C-H⋯N contacts are present in the crystal.

Related literature

For the structure at room temperature, see: Ribar et al. (1974 ▶). For the structure of the parent compound isoquinoline, see: Hensen et al. (1999 ▶). The C—N bond length in the structure of Ribar et al. (1974 ▶) clearly lies outside of the main distribution for 19 relevant structural fragments in the Cambridge Structural Database, being the second shortest bond in the sample [one shorter bond exists for refcode SAKCIQ, but this structure has R1 = 14.2% (Trumpp-Kallmeyer et al., 1998 ▶)]. The corresponding C—N bond length in this redetermination lies exactly at the mean of the CSD sample.

Experimental

Crystal data

C10H9N

M = 143.18

Monoclinic,

a = 6.1991 (4) Å

b = 7.4176 (6) Å

c = 16.5421 (12) Å

β = 93.438 (2)°

V = 759.28 (10) Å3

Z = 4

Mo Kα radiation

μ = 0.07 mm−1

T = 150 K

0.25 × 0.15 × 0.12 mm

Data collection

Bruker–Nonius X8 APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ▶) T min = 0.826, T max = 0.991

9801 measured reflections

1844 independent reflections

1171 reflections with I > 2σ(I)

R int = 0.034

Refinement

R[F 2 > 2σ(F 2)] = 0.042

wR(F 2) = 0.119

S = 1.06

1844 reflections

101 parameters

H-atom parameters constrained

Δρmax = 0.24 e Å−3

Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2003 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810039838/hb5670sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810039838/hb5670Isup2.hkl

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

C10H9N	F(000) = 304
Mr = 143.18	Dx = 1.253 Mg m−3
Monoclinic, P21/c	Melting point = 336–338 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 6.1991 (4) Å	Cell parameters from 1780 reflections
b = 7.4176 (6) Å	θ = 2.5–25.4°
c = 16.5421 (12) Å	µ = 0.07 mm−1
β = 93.438 (2)°	T = 150 K
V = 759.28 (10) Å3	Block, colourless
Z = 4	0.25 × 0.15 × 0.12 mm

Bruker–Nonius X8 APEXII CCD diffractometer	1844 independent reflections
Radiation source: fine-focus sealed tube	1171 reflections with I > 2σ(I)
graphite	Rint = 0.034
thin–slice ω and φ scans	θmax = 28.4°, θmin = 3.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −7→8
Tmin = 0.826, Tmax = 0.991	k = −9→9
9801 measured reflections	l = −21→20

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.119	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0637P)2] where P = (Fo2 + 2Fc2)/3
1844 reflections	(Δ/σ)max < 0.001
101 parameters	Δρmax = 0.24 e Å−3
0 restraints	Δρmin = −0.20 e Å−3

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.

	x	y	z	Uiso*/Ueq
C1	0.11212 (16)	0.91552 (15)	0.31390 (6)	0.0232 (3)
H1A	−0.0145	0.9742	0.3301	0.028*
N2	0.26422 (14)	0.87917 (12)	0.37033 (5)	0.0247 (3)
C3	0.44782 (16)	0.79419 (15)	0.34720 (7)	0.0234 (3)
C4	0.47647 (16)	0.75059 (15)	0.26814 (7)	0.0232 (3)
H4A	0.6070	0.6944	0.2544	0.028*
C5	0.32884 (18)	0.74255 (15)	0.12395 (7)	0.0257 (3)
H5A	0.4564	0.6873	0.1066	0.031*
C6	0.16084 (19)	0.77766 (16)	0.06908 (7)	0.0294 (3)
H6A	0.1709	0.7434	0.0141	0.035*
C7	−0.02738 (18)	0.86413 (16)	0.09309 (7)	0.0289 (3)
H7A	−0.1420	0.8894	0.0540	0.035*
C8	−0.04638 (16)	0.91186 (15)	0.17202 (7)	0.0247 (3)
H8A	−0.1734	0.9708	0.1877	0.030*
C9	0.12341 (16)	0.87349 (14)	0.23056 (6)	0.0205 (3)
C10	0.31404 (16)	0.78813 (14)	0.20670 (7)	0.0209 (3)
C11	0.61079 (18)	0.74985 (17)	0.41473 (7)	0.0317 (3)
H11A	0.6495	0.8598	0.4451	0.048*
H11B	0.7403	0.6991	0.3923	0.048*
H11C	0.5493	0.6617	0.4510	0.048*

	U11	U22	U33	U12	U13	U23
C1	0.0222 (6)	0.0219 (7)	0.0259 (6)	0.0014 (5)	0.0044 (5)	0.0006 (5)
N2	0.0262 (5)	0.0249 (6)	0.0232 (5)	0.0014 (4)	0.0022 (4)	0.0010 (4)
C3	0.0235 (6)	0.0196 (7)	0.0271 (7)	−0.0011 (4)	0.0003 (5)	0.0040 (5)
C4	0.0198 (5)	0.0212 (6)	0.0289 (7)	0.0011 (4)	0.0050 (5)	0.0025 (5)
C5	0.0300 (6)	0.0221 (6)	0.0258 (7)	0.0000 (5)	0.0089 (5)	−0.0002 (5)
C6	0.0402 (7)	0.0277 (7)	0.0206 (6)	−0.0059 (5)	0.0043 (5)	0.0007 (5)
C7	0.0287 (6)	0.0299 (7)	0.0274 (7)	−0.0049 (5)	−0.0050 (5)	0.0048 (5)
C8	0.0216 (6)	0.0233 (7)	0.0290 (7)	−0.0006 (4)	0.0001 (5)	0.0028 (5)
C9	0.0211 (5)	0.0172 (6)	0.0233 (6)	−0.0019 (4)	0.0028 (4)	0.0021 (5)
C10	0.0223 (6)	0.0173 (6)	0.0235 (6)	−0.0028 (4)	0.0042 (4)	0.0016 (5)
C11	0.0303 (6)	0.0335 (8)	0.0307 (7)	0.0015 (5)	−0.0040 (5)	0.0053 (6)

C1—N2	1.3144 (13)	C6—C7	1.4093 (16)
C1—C9	1.4194 (15)	C6—H6A	0.950
C1—H1A	0.950	C7—C8	1.3646 (15)
N2—C3	1.3753 (13)	C7—H7A	0.950
C3—C4	1.3690 (15)	C8—C9	1.4157 (14)
C3—C11	1.4971 (15)	C8—H8A	0.950
C4—C10	1.4148 (15)	C9—C10	1.4174 (15)
C4—H4A	0.950	C11—H11A	0.980
C5—C6	1.3649 (16)	C11—H11B	0.980
C5—C10	1.4184 (16)	C11—H11C	0.980
C5—H5A	0.950
N2—C1—C9	124.73 (10)	C8—C7—H7A	119.7
N2—C1—H1A	117.6	C6—C7—H7A	119.7
C9—C1—H1A	117.6	C7—C8—C9	119.93 (10)
C1—N2—C3	117.83 (9)	C7—C8—H8A	120.0
C4—C3—N2	122.08 (10)	C9—C8—H8A	120.0
C4—C3—C11	122.72 (10)	C8—C9—C10	119.83 (10)
N2—C3—C11	115.20 (10)	C8—C9—C1	122.84 (10)
C3—C4—C10	120.81 (10)	C10—C9—C1	117.33 (10)
C3—C4—H4A	119.6	C4—C10—C9	117.21 (10)
C10—C4—H4A	119.6	C4—C10—C5	124.19 (10)
C6—C5—C10	120.36 (10)	C9—C10—C5	118.59 (10)
C6—C5—H5A	119.8	C3—C11—H11A	109.5
C10—C5—H5A	119.8	C3—C11—H11B	109.5
C5—C6—C7	120.73 (11)	H11A—C11—H11B	109.5
C5—C6—H6A	119.6	C3—C11—H11C	109.5
C7—C6—H6A	119.6	H11A—C11—H11C	109.5
C8—C7—C6	120.54 (11)	H11B—C11—H11C	109.5
C9—C1—N2—C3	−0.04 (17)	N2—C1—C9—C8	178.66 (10)
C1—N2—C3—C4	1.19 (16)	N2—C1—C9—C10	−0.81 (17)
C1—N2—C3—C11	−177.61 (9)	C3—C4—C10—C9	0.55 (16)
N2—C3—C4—C10	−1.46 (17)	C3—C4—C10—C5	−178.11 (10)
C11—C3—C4—C10	177.24 (10)	C8—C9—C10—C4	−178.97 (9)
C10—C5—C6—C7	1.80 (17)	C1—C9—C10—C4	0.51 (15)
C5—C6—C7—C8	−1.03 (18)	C8—C9—C10—C5	−0.23 (16)
C6—C7—C8—C9	−0.38 (17)	C1—C9—C10—C5	179.26 (9)
C7—C8—C9—C10	0.99 (16)	C6—C5—C10—C4	177.49 (10)
C7—C8—C9—C1	−178.46 (10)	C6—C5—C10—C9	−1.16 (16)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5A···N2i	0.95	2.88	3.6891 (14)	144
C6—H6A···N2ii	0.95	2.64	3.5813 (15)	170

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5A⋯N2i	0.95	2.88	3.6891 (14)	144
C6—H6A⋯N2ii	0.95	2.64	3.5813 (15)	170

Symmetry codes: (i) ; (ii) .