1,5-Di­meth­­oxy­naphthalene

The title compound, C₁₂H₁₂O₂, lies across an inversion centre. The mol­ecular structure suggests that the meth­oxy groups in the 1- and 5-positions of the naphthalene moiety do not significantly distort the planar conformation of the ring system, which has a maximum deviation of 0.0025 (9) Å. In the crystal, mol­ecules pack in a herringbone arrangement in layers parallel to (100) and with chains propagating along [101] formed by very weak C—H⋯O inter­actions.

Related literature

For details of the uses of 1,5-di­meth­oxy­naphthalene, see: Ashton et al. (1991); Amabilino & Veciana (2003); Kim et al. (2008); Kato et al. (2003); Rawson et al. (2006). For related compounds, see: Allen & Kirby (1984); Beintema (1965); Belskii et al. (1990); Bolte & Bauch (1998); Cosmo et al. (1990); Cruickshank (1957); Gaultier & Hauw (1967); Pawley & Yeats (1969); Rozycka-Sokolowska & Marciniak (2009); Rozycka-Sokolowska et al. (2004, 2005); Wiedenfeld et al. (1999); Wilson et al. (1996); Wilson (1997). For details of the low-temperature device used, see: Cosier & Glazer (1986). For details of the H-atom treatment, see: Cooper et al. (2010). For Cambridge Structural Database, see: Allen (2002).

Experimental

Crystal data

• C₁₂H₁₂O₂

• M_r = 188.23

• Monoclinic, P 2₁ /c

• a = 7.0412 (3) Å

• b = 10.1058 (4) Å

• c = 6.5773 (2) Å

• β = 95.509 (3)°

• V = 465.86 (3) ų

• Z = 2

• Cu Kα radiation

• μ = 0.73 mm⁻¹

• T = 150 K

• 0.18 × 0.08 × 0.01 mm

Data collection

• Oxford Diffraction SuperNova diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007) T_min = 0.59, T_max = 1.00

• 7624 measured reflections

• 975 independent reflections

• 890 reflections with I > 2σ(I)

• R_int = 0.027

Refinement

• R[F² > 2σ(F²)] = 0.034

• wR(F²) = 0.093

• S = 1.00

• 971 reflections

• 64 parameters

• H-atom parameters constrained

• Δρ_max = 0.22 e Å⁻³

• Δρ_min = −0.18 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H73⋯O6^i	0.98	2.70	3.495 (1)	139
Symmetry code: (i) -x, -y+1, -z+1.

Data collection: SUPERNOVA (Oxford Diffraction, 2007); cell refinement: CrysAlis PRO (Oxford Diffraction, 2007); data reduction: CrysAlis PRO; program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996); software used to prepare material for publication: CRYSTALS.

Supporting information

S1. Comment

1,5-Dimethoxynaphthalene has numerous industrial applications and uses. It is employed in the synthesis of pesticides (Kim et al., 2008) for the agriculture industry, involved in the preparation of polyhydric alcohols (Kato et al., 2003), as well as a component in molecular magnetic devices (Ashton et al., 1991) for the electronics industry. It is also involved in the synthesis of more complex paramagnetic supramolecular architectures including rotaxanes and catenanes (Amabilino & Veciana, 2003, Rawson et al., 2006). Despite this, reports discussing single-crystal studies of naphthalene (Pawley et al., 1969; Wilson et al., 1996; Wilson et al., 1997) and its analogues including naphthol (Rozycka-Sokolowska, et al., 2004; Rozycka-Sokolowska et al., 2009; CSD (Allen, 2002) refcode NAPHOLO1), 1,4- and 1,5-dihydroxynaphthalene (Gaultier, et al., 1967; CSD refcode NPHHQU10), Belskii et al., 1990; CSD refcode VOGRUE) and 1,4-dimethoxynaphthalene (Wiedenfeld, et al., 1999; CSD refcode ALUJIA; Cosmo et al., 1990; CSD refcode MATFES) confirm that the crystal structure of 1,5-dimethoxynaphthalene (I) is not known.

The colorless single-crystal of 1,5-dimethoxynaphthalene was crystallized while attemping to crystallize the rac-1,1'-bi-2-naphthol/1,5-dimethoxynaphalene complex from a blend of methanol/ethylacetate solvents. It crystallizes in the monoclinic space group P2₁/c with the molecule located on an inversion centre. The refined molecule and the labeling scheme are given in Fig. 1. It exhibits a herringbone packing motif and the molecules are arranged in layers parallel to the lattice plane (100) as shown in Fig. 2. All bond distances and angles fall within expected ranges.

In 1,5-dimethylnaphthalene (Gaultier, et al., 1967; Belskii et al., 1990; Beintema, 1965) as well as those in 1,4-dimethoxynaphthalene (Wiedenfeld, et al., 1999), 1,8-dimethoxynaphthalene (Cosmo et al., 1990), the steric interactions of the methyl groups cause a deviation from planarity in the naphthalene moiety. However, the ten-membered aromatic ring formed by atoms C1–C10 in (I) is planar; the steric interactions of the methoxy and H atoms do not cause any significant deviation from planarity. The exterior C4—C5—C4' angle (122.13 (9)°; symmetry operator indicated by a prime is -x + 1, -y + 1, -z + 2) in the naphathalene moiety shows no evidence of distortion in the naphthalene core associated with 1,5-disubstitutions. This suggests that the methoxy group seems to be restrained in the packing structure as a result of steric interaction between methoxy group and hydrogen atoms that reduce the propensity of the methoxy group to freely rotate in the crystal structure.

The methoxy substituents point away from the centre of the naphthalene moiety and each one forms a weak hydrogen bonded dimer with the neighbouring molecule. Since the molecule sits on an inversion centre, this leads to the formation of chains in the [101] direction (Fig. 3) via the weak intermolecular C—H···O hydrogen bonds involving the methoxy groups (with a C···O distance of 3.495 (1) Å).

In conclusion, the structure suggests that the methoxy groups in 1 and 5 positions around the naphthalene moiety do not significantly distort the planar conformation of the naphthalene, and the size of the groups and their positions are not influenced by steric interactions with the naphthalene moiety.

Related literature

For details of the uses of 1,5-dimethoxynaphthalene, see: Ashton et al. (1991); Amabilino & Veciana (2003); Kim et al. (2008); Kato et al. (2003); Rawson et al. (2006); For related compounds, see: Allen & Kirby (1984); Beintema (1965); Belskii et al. (1990); Bolte & Bauch (1998); Cosmo et al. (1990); Cruickshank (1957); Gaultier & Hauw (1967); Pawley & Yeats (1969); Rozycka-Sokolowska & Marciniak (2009); Rozycka-Sokolowska et al. (2004); Rozycka-Sokolowska et al. (2005); Wiedenfeld et al. (1999); Wilson et al. (1996); Wilson (1997); For details of the low-temperature device used, see: Cosier & Glazer (1986); For details of the H-atom treatment, see: Cooper et al. (2010). For Cambridge Structural Database, see: Allen (2002).

S2. Experimental

The crystal of 1,5-dimethoxynaphthalene was obtained as a result of attemping to crystallize crystal complex of 1:1 mixture of rac-1,1'-bi-2-naphthol/1,5-dimethoxynaphalene from mixture of methanol and ethylacetate.

S3. Refinement

The H atoms were all located in a difference map, but those attached to carbon atoms were repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles to regularize their geometry (C—H in the range 0.93–0.98, O—H = 0.82 Å) and U_iso(H) (in the range 1.2–1.5 times U_eq of the parent atom), after which the positions were refined with riding constraints (Cooper et al., 2010).

Computing details

Data collection: SUPERNOVA (Oxford Diffraction, 2007); cell refinement: CrysAlis PRO (Oxford Diffraction, 2007); data reduction: CrysAlis PRO (Oxford Diffraction, 2007); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996); software used to prepare material for publication: CRYSTALS (Betteridge et al., 2003).

Figures

	Fig. 1. The title compound with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitary radius [symmetry operator indicated by a prime is -x + 1, -y + 1, -z + 2].
	Fig. 2. The packing in (I) viewed along [100] and showing the herringbone arrangement.
	Fig. 3. Intermolecular C—H···O hydrogen bonds forming chains that propagate along [101] (symmetry operator indicated by a double prime is -x, -y + 1, -z + 1).

1,5-Dimethoxynaphthalene

Crystal data

C12H12O2	F(000) = 200
Mr = 188.23	Dx = 1.342 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: -P 2ybc	Cell parameters from 3622 reflections
a = 7.0412 (3) Å	θ = 4–77°
b = 10.1058 (4) Å	µ = 0.73 mm^−1
c = 6.5773 (2) Å	T = 150 K
β = 95.509 (3)°	Plate, clear_pale_colourless
V = 465.86 (3) Å^3	0.18 × 0.08 × 0.01 mm
Z = 2

Data collection

Oxford Diffraction SuperNova diffractometer	890 reflections with I > 2.0σ(I)
Graphite monochromator	Rint = 0.027
ω scans	θmax = 76.7°, θmin = 6.3°
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2007)	h = −8→7
Tmin = 0.59, Tmax = 1.00	k = −12→12
7624 measured reflections	l = −8→8
975 independent reflections

Refinement

Refinement on F^2	Primary atom site location: other
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.034	H-atom parameters constrained
wR(F^2) = 0.093	Method = Modified Sheldrick w = 1/[σ^2(F^2) + (0.06P)^2 + 0.1P], where P = (max(Fo^2,0) + 2Fc^2)/3
S = 1.00	(Δ/σ)max = 0.0004116
971 reflections	Δρmax = 0.22 e Å^−3
64 parameters	Δρmin = −0.18 e Å^−3
0 restraints

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.46630 (14)	0.35777 (9)	1.31198 (15)	0.0246
C2	0.28469 (14)	0.36191 (10)	1.19978 (15)	0.0251
C3	0.25474 (13)	0.43124 (9)	1.02089 (14)	0.0226
C4	0.40796 (12)	0.50104 (9)	0.94482 (13)	0.0202
C5	0.38406 (14)	0.57492 (9)	0.75848 (14)	0.0219
O6	0.20285 (10)	0.57222 (7)	0.66380 (11)	0.0274
C7	0.16539 (15)	0.64994 (10)	0.48270 (16)	0.0296
H11	0.4837	0.3088	1.4350	0.0297*
H21	0.1819	0.3157	1.2519	0.0309*
H31	0.1296	0.4338	0.9479	0.0276*
H73	0.0325	0.6342	0.4324	0.0427*
H72	0.1849	0.7431	0.5170	0.0424*
H71	0.2476	0.6232	0.3793	0.0432*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0273 (5)	0.0242 (5)	0.0220 (4)	−0.0007 (4)	0.0001 (4)	0.0018 (3)
C2	0.0220 (5)	0.0258 (5)	0.0277 (5)	−0.0029 (4)	0.0041 (4)	0.0001 (4)
C3	0.0179 (5)	0.0236 (5)	0.0260 (5)	−0.0001 (3)	−0.0002 (3)	−0.0027 (3)
C4	0.0195 (5)	0.0186 (4)	0.0220 (4)	0.0012 (3)	−0.0002 (4)	−0.0031 (3)
C5	0.0210 (5)	0.0214 (5)	0.0225 (5)	0.0011 (3)	−0.0023 (4)	−0.0024 (3)
O6	0.0223 (4)	0.0314 (4)	0.0268 (4)	−0.0028 (3)	−0.0064 (3)	0.0060 (3)
C7	0.0298 (5)	0.0308 (5)	0.0261 (5)	−0.0002 (4)	−0.0077 (4)	0.0044 (4)

Geometric parameters (Å, º)

C1—C5^i	1.3717 (14)	C4—C4^i	1.4236 (17)
C1—C2	1.4143 (13)	C4—C5	1.4312 (13)
C1—H11	0.946	C5—O6	1.3653 (11)
C2—C3	1.3683 (14)	O6—C7	1.4301 (11)
C2—H21	0.953	C7—H73	0.975
C3—C4	1.4197 (13)	C7—H72	0.974
C3—H31	0.962	C7—H71	0.972
C5^i—C1—C2	119.63 (9)	C3—C4—C5	122.01 (9)
C5^i—C1—H11	120.5	C4—C5—C1^i	121.13 (9)
C2—C1—H11	119.9	C4—C5—O6	114.09 (8)
C1—C2—C3	121.39 (9)	C1^i—C5—O6	124.78 (9)
C1—C2—H21	118.6	C5—O6—C7	117.29 (8)
C3—C2—H21	120.0	O6—C7—H73	106.7
C2—C3—C4	119.86 (9)	O6—C7—H72	109.1
C2—C3—H31	120.1	H73—C7—H72	110.2
C4—C3—H31	120.1	O6—C7—H71	110.8
C4^i—C4—C3	119.90 (10)	H73—C7—H71	109.5
C4^i—C4—C5	118.09 (11)	H72—C7—H71	110.5

Symmetry code: (i) −x+1, −y+1, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H73···O6^ii	0.98	2.70	3.495 (1)	139

Symmetry code: (ii) −x, −y+1, −z+1.

 

Footnotes

‡Visiting: Chemical Crystallography, Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, England.