4-Chloro-1-naphthol

Mol­ecules of the title compound, C₁₀H₇ClO, (I), are connected by a single strong O-H...O hydrogen bond into a simple C(2) chain, which runs parallel to the c axis and is additionally stabilized by inter­molecular [pi]-[pi] stacking inter­actions. The significance of this study lies in the comparison drawn between the crystal structure of (I) and those of several of its simple analogues. This comparison shows a close similarity in the packing of the mol­ecules that form [pi]-stacks along the shortest crystallographic axes. A substantial spatial overlap is observed between adjacent mol­ecules in such a [pi]-stack, depending mainly on the kind of substituent.

S1. Comment

Naphthalene derivatives are used in various scientific fields, such as metal complexation, materials chemistry, medicinal chemistry, structural chemistry, molecular recognition, macromolecular chemistry, supramolecular chemistry, fluorescence chemistry and asymmetric synthesis, as backbones, platforms or functional devices (Ohta et al., 2005, and references 8–16 therein). Halo-substituted hydroxy-aromatic compounds (among them also the title compound) are a class of starting matrials for the preparation of bis(hydroxy-aromatic) compounds, which find many uses in chemical applications such as dyes, plastics, pharmaceuticals and agrochemicals, and in the forming polymers such as polycarbonates, polyestercarbonates, polyesters, polyethers, polyetherimides and polyether ketones (Patel et al., 2005). A search of the Cambridge Structural Database (CSD, Version 5.30, November 2008; Allen, 2002) for chloro-substituted hydroxy-derivatives of naphthalene revealed only five reports of four chloro-substituted naphthalenediols, namely 1,5-dichloro-2,6-dihydroxynaphthalene [CSD refcodes JIMFAM (Nakasuji et al., 1991) and JIMFAM01 (Ahn et al., 1995)], 1,5-dichloro-2,6-naphthoquinone 1,5-dichloro-2,6-dihydroxynaphthalene [CSD refcode JIMDUE (Nakasuji et al., 1991)], 1,5-dichloronaphthalene-2,6-diol dioxane solvate [CSD refcode RAYPOW (Ahn et al., 1995)] and bis(1,4-dichloronaphthalene-2,3-diol) dioxane [CSD refcode ZIPYEC (Ahn et al., 1994)], and no prior reports of the structures of chloro-substituted naphthols. Thus, this paper concerning the results of structural studies of the title compound, (I), would appear to be the first example involving a chloronaphthol. The crystal structure of (I) is presented here and is also compared with those of five of its simple analogues, namely 1-hydroxynaphthalene, (II), 1,4-dihydroxynaphthalene, (III), 1,4-dichloronaphthalene, (IV), 1,4-dibromonaphthalene, (V) and naphthalene, (VI) [CSD refcodes NAPHOL01 (Rozycka-Sokolowska et al., 2004), NPHHQU10 (Gaultier & Hauw, 1967), DCLNAQ (Bellows et al., 1978), DBRNAQ01 (Trotter, 1986) and NAPHTA15 (Oddershede & Larsen, 2004), respectively].

Compound (I) consists of a naphthalene ring with two substituents attached to it on atoms C1 and C4 (Fig. 1). Although the presence of a hydroxyl group and a Cl atom at positions 1 and 4, respectively, modifies the geometric parameters within the aromatic rings [the C—C bond distances and C—C—C bond angles lie in the ranges 1.355 (4)–1.431 (3) Å and 117.6 (3)–124.0 (2)°, respectively; Table 1], the naphthalene ring remains planar; the largest out-of-plane deviation is -0.017 Å for atom C1. Atoms O1 and Cl1 deviate from the plane of this ring by only 0.003 (2) and 0.053 (1) Å, respectively. The C4—Cl1 bond length of 1.748 (3) Å is close to those observed in several chloro-derivatives of napthalene, such as 1,2,3,4,6,7-, 1,2,3,5,6,7-, 1,2,4,5,6,8- and 1,2,4,5,7,8-hexachloronaphthalene [CSD refcodes YAFHUI and YAFYEU (Jakobsson et al., 1992) and YILROA and YILRUG (Jakobsson et al., 1994), respectively] and (IV), as well as in compounds such as JIMFAM and JIMFAM01, JIMDUE, RAYPOV [Or RAYPOW as above?] and ZIPYEC.

As can be seen in Fig. 1, there are two weak intramolecular hydrogen-bonding contacts (Table 2); the first interaction, C—H···O, links aromatic atom C9 with hydroxy atom O1, and the second interaction, C—H···Cl, exists between aromatic atom C6 and atom Cl1. Both these interactions generate an S(5) graph-set motif (Bernstein et al., 1995). The presence of an intramolecular C—H···Cl interaction with such a graph-set descriptor is in agreement with the structures observed for naphthalene derivatives which have Cl substituents at positions 1, 4, or 1 and 4, and simultaneously possess substituents at positions 5, 8, or 5 and 8, such as DCLNAQ, YAFHUI and ZIPYEC.

In the crystal structure of (I) there is a single strong and practically linear O—H···O hydrogen bond (Table 2) that links hydroxy atom O1 at (x, y, z), via atom H1, to hydroxy atom O1 belonging to the molecule at (2 - x, 2 - y, -1/2 + z), so generating a simple C(2) chain (Fig. 2), which runs parallel to the shortest crystallographic c axis and is built from molecules related by the 2₁ screw axis. This chain is additionally stabilized by intermolecular π–π stacking interactions involving the C1–C5/C10 (centroid Cg1) and C5–C10 (centroid Cg2) benzene rings (Fig. 2). The perpendicular distance of the ring centroids Cg1 and Cg2 from the symmetry-related centroids Cg2 at (x, y, -1 + z) and Cg1 at (x, y, 1 + z), respectively, is 3.576 Å, and the centroid-to-centroid separation is 3.714 (2) Å. The planes of the rings C1–C5/C10 and C5–C10 make an angle of only 1.02°. Two C(2) chains run through each unit cell and there are no direction-specific interactions between them. In the crystal structure of (I), there are no close contacts between Cl atoms, the shortest Cl···Cl distance being 4.189 (2) Å.

It is worth mentioning that the presence of the 2₁ screw axis along the shortest crystallographic axis and the formation of molecular stacks along this axis are the common characteristics of the crystal packing in (I) and in four of its simple analogues, (II)–(V). In the case of (II) and (III), adjacent stacks are held together mainly by a strong interstack O—H···O hydrogen bond, and in (IV) and (V) by a weak halogen···halogen interaction such as Cl···Cl and Br···Br interactions, respectively, with distances of 3.621 and 3.613–3.701 Å. Similar to (I), the O—H···O hydrogen bond in (II) and the halogen···halogen interactions in (IV) and (V) link molecules related by the 2₁ screw axis into simple infinite chains parallel to the shortest axes [b = 4.7980 (10), 3.9394 (6) and 4.063 (3) Å, respectively; Fig. 3(a)–(c)]. Although the O—H···O hydrogen bond in the crystal stucture of (III) can be desribed by the same C(2) graph-set motif as those in (I) and (II), in contrast with the supramolecular aggregation in these two compounds the single hydrogen bond connects molecules of (III) into a two-dimensional sheet parallel to (100) and built up from R₄⁴(18) rings (Fig. 3d).

The application of the phenomenological approach proposed by Curtis et al. (2004) for the description of distortions from an `ideal' cofacial π-stack based on `pitch' and `roll' parameters, such as the pitch (P) and roll (R) angles and the pitch (dp) and roll (dr) distances, in combination with a simple model introduced by Janzen et al. (2004) for the approximation of the area overlap (AO) of adjacent π-stacking molecules, reveals that the solid-state packing of (I) provides substantial spatial overlap between molecules in the π-stack (P > R, dp > dr, AO = 40.7%; Table 3). Analysis of the parameters given in Table 3 indicates that π-stacking with substantial spatial overlap between molecules is also observed for (II)–(V). Thus, it may be concluded that a modification of the molecular structure of (VI) by the replacement of one C H atom at position 1 by a hydroxy group, or two H atoms at positions 1 and 4 by (i) one hydroxy group and one halogen (Cl or Br) atom, (ii) two hydroxy groups, or (iii) two halogen atoms, results not only in the elimination of intermolecular C—H···π(arene) interactions and the appearance of O—H···O hydrogen bonds [in (I)–(III)] or halogen···halogen interactions [in (IV) and (V)], but primarily in a transformation of the arrangement of the aromatic rings, from typical herringbone in (VI) with no π-overlap between adjacent molecules (P < R, dp < dr; Table 3) to practically parallel π-stacking in (I)–(V) (P > R, dp > dr). It is also worth stressing that hydroxy and halogen substitution at positions 1 and 4 of the molecule of (VI) not only promote π-stacking but also influence the overlap between adjacent molecules in the π-stack. The area of overlap depends mainly on the kind of substituent; among the five naphthalene derivatives considered here, three with one or two halogen substituents [(I), (IV) and (V)] distinguish themselves with larger (average ca 11%) area overlap than those that possess only hydroxy groups as substituents [(II) and (III)] (Table 3).

Bearing in mind that the materials yielding π-stacking with substantial spatial overlap in the solid state are particularly attractive because they often lead to devices with high charge-carrier mobilities (Anthony et al., 2002; Li et al., 1998; Horowitz et al., 1996; Laquindanum et al., 1997), and taking into account the fact that in the crystal structure of (I) such π-stacking is predominant, we can suppose that this derivative of (VI) will turn out to be a promising material for device applications, particularly in the area of functional devices such as organic field-effect transistors (OFETs).

S2. Experimental

4-Chloro-1-naphthol was obtained from Sigma and used without further purification. Crystals of (I) suitable for X-ray diffraction analysis were obtained by slow evaporation of a solution in ethyl acetate at a constant temperature of 279 K.

S3. Refinement

All aromatic H atoms were positioned geometrically and constrained to ride on their parent atoms, with C—H = 0.93 Å and with U_iso(H) = 1.2U_eq(C). The hydroxyl H atom was located in a Fourier difference map and refined isotropically, with O—H = 0.88 (4) Å.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2009).

Figures

	Fig. 1. A view of the molecule of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Dashed lines depict the intramolecular C—H···O and C—H···Cl hydrogen bonds forming patterns with the S(5) descriptor.
	Fig. 2. Part of the crystal structure of (I), showing the interstack O—H···O hydrogen bond forming a C(2) chain along the [001] direction, and the intrastack π–π interactions. H atoms not involved in hydrogen bonding have been omitted for clarity. Cg1 and Cg2 are the centroids of the C1–C5/C10 and C5–C10 benzene rings, respectively, and are denoted by small spheres. [Symmetry codes: (i) 2 - x, 2 - y, -1/2 + z; (ii) 1 - x, 1 - y, -3/2 + z; (iii) 1 - x, 1 - y, 1/2 + z.]
	Fig. 3. Part of the crystal structures of (a) (II), (b) (IV), (c) (V) and (d) (III), showing the intermolecular π–π interactions (thin dashed lines) linking the molecules of each of these compounds into stacks parallel to the shortest crystallographic axes, as well as the interstack O—H···O and halogen···halogen interactions (thick dashed lines). All H atoms not involved in these interactions have been omitted for clarity. The centroids of the benzene aromatic rings (Cg) are denoted by small spheres.

4-Chloro-1-naphthol

Crystal data

C10H7ClO	F(000) = 368
Mr = 178.61	Dx = 1.430 Mg m^−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 4455 reflections
a = 11.7106 (8) Å	θ = 2.4–25.0°
b = 16.9105 (8) Å	µ = 0.40 mm^−1
c = 4.1894 (3) Å	T = 290 K
V = 829.64 (9) Å^3	Columnar, white
Z = 4	0.49 × 0.13 × 0.08 mm

Data collection

Oxford Xcalibur3 CCD area-detector diffractometer	1116 independent reflections
Radiation source: Enhance (Mo) X-ray Source	854 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
ω scans	θmax = 25.0°, θmin = 2.4°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008)	h = −13→13
Tmin = 0.945, Tmax = 0.973	k = −18→20
4455 measured reflections	l = −4→3

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.027	w = 1/[σ^2(Fo^2) + (0.0371P)^2 + 0.0846P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.079	(Δ/σ)max = 0.001
S = 1.13	Δρmax = 0.13 e Å^−3
1116 reflections	Δρmin = −0.15 e Å^−3
114 parameters	Extinction correction: SHELXL (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.026 (3)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), with 289 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.07 (13)

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
Cl1	0.74761 (7)	0.66988 (3)	0.0504 (4)	0.0830 (3)
O1	0.92790 (18)	0.98825 (11)	−0.2365 (6)	0.0671 (6)
H1	0.978 (4)	0.984 (2)	−0.393 (11)	0.124 (16)*
C1	0.8866 (2)	0.91225 (13)	−0.1798 (7)	0.0513 (6)
C2	0.9425 (2)	0.84651 (17)	−0.2788 (8)	0.0642 (8)
H2	1.0101	0.8510	−0.3941	0.077*
C3	0.8976 (2)	0.77132 (15)	−0.2056 (8)	0.0654 (8)
H3	0.9358	0.7261	−0.2727	0.078*
C4	0.7990 (2)	0.76443 (14)	−0.0382 (7)	0.0542 (7)
C5	0.73768 (19)	0.83158 (11)	0.0692 (8)	0.0434 (5)
C6	0.6339 (2)	0.82760 (14)	0.2403 (7)	0.0584 (7)
H6	0.6020	0.7785	0.2864	0.070*
C7	0.5796 (2)	0.89487 (16)	0.3390 (7)	0.0636 (8)
H7	0.5110	0.8911	0.4501	0.076*
C8	0.6263 (2)	0.96944 (14)	0.2743 (8)	0.0615 (7)
H8	0.5893	1.0147	0.3463	0.074*
C9	0.7257 (2)	0.97619 (14)	0.1065 (6)	0.0527 (7)
H9	0.7552	1.0261	0.0623	0.063*
C10	0.78430 (19)	0.90787 (13)	−0.0009 (6)	0.0448 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.1126 (6)	0.0367 (3)	0.0997 (6)	−0.0026 (3)	−0.0003 (5)	−0.0013 (5)
O1	0.0734 (13)	0.0641 (11)	0.0637 (13)	−0.0243 (9)	0.0043 (12)	0.0000 (12)
C1	0.0531 (15)	0.0538 (14)	0.0470 (17)	−0.0116 (11)	−0.0056 (13)	0.0009 (14)
C2	0.0552 (17)	0.0721 (17)	0.065 (2)	0.0017 (13)	0.0067 (15)	−0.0056 (16)
C3	0.0706 (18)	0.0561 (15)	0.069 (2)	0.0149 (12)	0.0005 (17)	−0.0106 (16)
C4	0.0633 (17)	0.0401 (13)	0.0593 (18)	0.0021 (10)	−0.0095 (13)	−0.0035 (12)
C5	0.0482 (13)	0.0376 (10)	0.0444 (13)	−0.0032 (9)	−0.0070 (12)	0.0004 (12)
C6	0.0619 (17)	0.0467 (14)	0.0666 (19)	−0.0086 (10)	−0.0002 (15)	0.0046 (14)
C7	0.0551 (16)	0.0663 (18)	0.069 (2)	0.0030 (12)	0.0081 (15)	0.0035 (16)
C8	0.0700 (18)	0.0490 (14)	0.0654 (18)	0.0130 (11)	−0.0015 (16)	0.0006 (17)
C9	0.0659 (17)	0.0375 (11)	0.0546 (18)	0.0016 (10)	−0.0042 (14)	−0.0006 (12)
C10	0.0487 (14)	0.0431 (12)	0.0425 (15)	−0.0033 (9)	−0.0098 (11)	−0.0001 (11)

Geometric parameters (Å, º)

Cl1—C4	1.748 (3)	C5—C6	1.413 (4)
O1—C1	1.394 (3)	C5—C10	1.431 (3)
O1—H1	0.88 (4)	C6—C7	1.367 (4)
C1—C2	1.355 (4)	C6—H6	0.9300
C1—C10	1.415 (3)	C7—C8	1.401 (4)
C2—C3	1.410 (4)	C7—H7	0.9300
C2—H2	0.9300	C8—C9	1.364 (4)
C3—C4	1.356 (4)	C8—H8	0.9300
C3—H3	0.9300	C9—C10	1.417 (3)
C4—C5	1.417 (3)	C9—H9	0.9300
C1—O1—H1	106 (2)	C7—C6—C5	120.9 (2)
C2—C1—O1	122.4 (3)	C7—C6—H6	119.5
C2—C1—C10	121.9 (2)	C5—C6—H6	119.5
O1—C1—C10	115.6 (2)	C6—C7—C8	120.6 (3)
C1—C2—C3	119.5 (3)	C6—C7—H7	119.7
C1—C2—H2	120.2	C8—C7—H7	119.7
C3—C2—H2	120.2	C9—C8—C7	120.5 (2)
C4—C3—C2	120.5 (2)	C9—C8—H8	119.7
C4—C3—H3	119.7	C7—C8—H8	119.7
C2—C3—H3	119.7	C8—C9—C10	120.6 (2)
C3—C4—C5	121.8 (2)	C8—C9—H9	119.7
C3—C4—Cl1	118.79 (19)	C10—C9—H9	119.7
C5—C4—Cl1	119.4 (2)	C1—C10—C9	122.4 (2)
C6—C5—C4	124.0 (2)	C1—C10—C5	118.6 (2)
C6—C5—C10	118.4 (2)	C9—C10—C5	119.0 (2)
C4—C5—C10	117.6 (3)
O1—C1—C2—C3	178.2 (3)	C6—C7—C8—C9	1.2 (5)
C10—C1—C2—C3	0.7 (4)	C7—C8—C9—C10	−1.0 (4)
C1—C2—C3—C4	0.1 (5)	C2—C1—C10—C9	179.4 (3)
C2—C3—C4—C5	0.0 (5)	O1—C1—C10—C9	1.7 (4)
C2—C3—C4—Cl1	−179.3 (3)	C2—C1—C10—C5	−1.7 (4)
C3—C4—C5—C6	179.0 (3)	O1—C1—C10—C5	−179.3 (3)
Cl1—C4—C5—C6	−1.7 (4)	C8—C9—C10—C1	179.0 (3)
C3—C4—C5—C10	−0.9 (4)	C8—C9—C10—C5	0.0 (4)
Cl1—C4—C5—C10	178.3 (2)	C6—C5—C10—C1	−178.3 (3)
C4—C5—C6—C7	179.5 (3)	C4—C5—C10—C1	1.7 (4)
C10—C5—C6—C7	−0.5 (5)	C6—C5—C10—C9	0.8 (4)
C5—C6—C7—C8	−0.4 (5)	C4—C5—C10—C9	−179.3 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O1^i	0.88 (4)	1.87 (4)	2.720 (3)	160 (3)
C6—H6···Cl1	0.93	2.69	3.085 (3)	106
C9—H9···O1	0.93	2.46	2.777 (3)	100

Symmetry code: (i) −x+2, −y+2, z−1/2.