6-Bromo-2-naphthol–piperazine (2/1)

In the title compound, 2C₁₀H₇BrO·C₄H₁₀N₂, the piperazine (pip) mol­ecule displays a chair conformation and is linked to two mol­ecules of 6-bromo-2-naphthol (bno) via O—H...N hydrogen bonds. Weak N—H...O hydrogen bonds from pip to bno mol­ecules result in chains propagating in [100]. The chains inter­act via C—H...π inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.041
• wR factor = 0.107
• Data-to-parameter ratio = 19.1

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR) is > 1.10
            Tmin and Tmax reported:      0.409     0.713
            Tmin and Tmax expected:      0.352     0.695
            RR =      1.135
            Please check that your absorption correction is appropriate.
            Value of measurement temperature given =   296.000
            Value of melting point given =     0.000
PLAT060_ALERT_4_C Ratio Tmax/Tmin (Exp-to-Rep) (too) Large .......       1.14
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.98
PLAT234_ALERT_4_C Large Hirshfeld Difference C9     --  C10     ..       0.11  Ang.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

During the past decade, the field of molecular co-crystals have received considerable attention, for example, the design, construction and properties of molecular co-crystals. Recently, many co-crystals containing some organic acids and bases, have been successfully prepared and characterized by some research groups (Wang et al., 2006a,b,c). Especially, co-crystals containing hydroxyl-naphthalene with some organic bases have been synthesized and characterized (Wang et al., 2008). As part of our investigations of co-crystals containing 6-bromo-2-naphthol (bno), we now report the structure of the co-crystal, (I), of bno and piperazine.

A view of the title structure is shown in Fig. 1. The asymmetric unit consists of two independent bno molecules and one independent molecule of piperazine. In the crystal structure of (I), the piperazine molecule display a chair conformation and links with two molecules of 6-bromo-2-naphthol via O—H···N hydrogen bonds. These motifs are extended to one-dimensional chains via intermolecular edge-to-face C—H···π packing interactions (Fig. 2 and Table 1).

Related literature

For related structures, see: Wang & Tang (2006a,b,c); Wang et al. (2008). Cg1, Cg2 and Cg5 are the centroids of atoms C1–C5,C10, C5–C10 and C15–C20, respectively.

S2. Experimental

A mixture of bno (446 mg, 1 mmol) and piperazine (86 mg, 1 mmol) was dissolved in methanol (10 ml), which was left at room temperature. Some colourless plates of (I0 were obtained after ten days. Analysis found (%): C, 54.28; H, 4.53; N, 5.28; requires (%): C, 54.16; H, 4.54; N, 5.26.

S3. Refinement

All the H atoms were located in a difference Fourier map. The carbon-bound hydrogen atoms were relocated to idealised positions (C—H = 0.93 A °), and refined as riding with U_iso(H) = 1.2U_eq(C). The oxygen- and nitrogen-bound hydrogen atoms were refined as riding in their as-found relative possitions with U_iso(H) = 1.5U_eq(O, N).

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. A drawing of (I), with displacement ellipsoids for the non-hydrogen atoms drawn at the 30% probability level.
	Fig. 2. Packing diagram of (I); hydrogen bonds are shown by dashed lines.

6-Bromo-2-naphthol–piperazine (2/1)

Crystal data

2C10H7BrO·C4H10N2	F(000) = 1072
Mr = 532.27	Dx = 1.575 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3655 reflections
a = 10.1327 (4) Å	θ = 2.5–27.5°
b = 16.2494 (7) Å	µ = 3.64 mm^−1
c = 14.3499 (5) Å	T = 296 K
β = 108.238 (2)°	Plate, colourless
V = 2244.02 (15) Å^3	0.30 × 0.30 × 0.10 mm
Z = 4

Data collection

Bruker SMART CCD diffractometer	5164 independent reflections
Radiation source: fine-focus sealed tube	2857 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
Detector resolution: 9.00 pixels mm^-1	θmax = 27.6°, θmin = 2.0°
ω scans	h = −13→13
Absorption correction: multi-scan (SADABS; Bruker, 2001)	k = −20→21
Tmin = 0.409, Tmax = 0.713	l = −18→18
16751 measured reflections

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.107	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.046P)^2 + 0.5753P] where P = (Fo^2 + 2Fc^2)/3
5164 reflections	(Δ/σ)max = 0.001
271 parameters	Δρmax = 0.52 e Å^−3
0 restraints	Δρmin = −0.39 e Å^−3

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
Br1	0.90393 (4)	0.69713 (3)	1.25794 (3)	0.07368 (16)
O1	0.5253 (2)	0.59439 (15)	0.67377 (16)	0.0644 (7)
H1B	0.4423	0.5842	0.6586	0.097*
C1	0.6945 (3)	0.6429 (2)	0.8149 (2)	0.0513 (8)
H1A	0.7491	0.6579	0.7762	0.062*
C2	0.5696 (3)	0.6067 (2)	0.7733 (2)	0.0500 (8)
C3	0.4883 (3)	0.5817 (2)	0.8315 (2)	0.0528 (8)
H3A	0.4037	0.5556	0.8023	0.063*
C4	0.5317 (3)	0.59511 (19)	0.9301 (2)	0.0521 (8)
H4A	0.4763	0.5783	0.9674	0.062*
C5	0.6582 (3)	0.63370 (18)	0.9756 (2)	0.0452 (8)
C6	0.7088 (3)	0.64743 (19)	1.0793 (2)	0.0520 (8)
H6A	0.6553	0.6318	1.1184	0.062*
C7	0.8328 (3)	0.6827 (2)	1.1201 (2)	0.0518 (8)
C8	0.9161 (3)	0.70853 (19)	1.0628 (3)	0.0567 (9)
H8A	1.0010	0.7341	1.0924	0.068*
C9	0.8716 (3)	0.6958 (2)	0.9645 (3)	0.0558 (9)
H9A	0.9273	0.7122	0.9272	0.067*
C10	0.7427 (3)	0.65831 (18)	0.9179 (2)	0.0445 (7)
C21	0.1839 (3)	0.6015 (2)	0.5035 (3)	0.0640 (10)
H21A	0.1860	0.6602	0.5158	0.077*
H21B	0.0877	0.5847	0.4757	0.077*
C22	0.2618 (3)	0.5824 (2)	0.4333 (2)	0.0560 (9)
H22A	0.2186	0.6104	0.3715	0.067*
H22B	0.3567	0.6020	0.4597	0.067*
C23	0.3232 (3)	0.4493 (2)	0.5094 (2)	0.0601 (9)
H23A	0.4194	0.4658	0.5383	0.072*
H23B	0.3209	0.3905	0.4974	0.072*
C24	0.2437 (4)	0.4687 (3)	0.5782 (3)	0.0710 (11)
H24A	0.1480	0.4510	0.5501	0.085*
H24B	0.2838	0.4396	0.6396	0.085*
N1	0.2484 (3)	0.5572 (2)	0.5960 (2)	0.0669 (8)
H1C	0.1994	0.5750	0.6287	0.100*
N2	0.2616 (3)	0.49323 (18)	0.41684 (19)	0.0567 (7)
H2A	0.3047	0.4879	0.3813	0.085*
Br2	0.41434 (4)	0.63994 (3)	1.24310 (3)	0.07881 (17)
O2	−0.0266 (2)	0.59459 (14)	0.65772 (15)	0.0587 (6)
H2B	−0.0912	0.5604	0.6430	0.088*
C11	0.1170 (3)	0.65519 (19)	0.8032 (2)	0.0436 (7)
H11A	0.1287	0.7005	0.7670	0.052*
C12	0.0343 (3)	0.59134 (18)	0.7567 (2)	0.0429 (7)
C13	0.0169 (3)	0.52264 (18)	0.8108 (2)	0.0470 (8)
H13A	−0.0407	0.4797	0.7795	0.056*
C14	0.0843 (3)	0.51849 (18)	0.9094 (2)	0.0450 (7)
H14A	0.0734	0.4720	0.9441	0.054*
C15	0.1700 (3)	0.58307 (17)	0.9598 (2)	0.0388 (7)
C16	0.2394 (3)	0.58006 (19)	1.0613 (2)	0.0458 (8)
H16A	0.2318	0.5338	1.0973	0.055*
C17	0.3176 (3)	0.6450 (2)	1.1062 (2)	0.0489 (8)
C18	0.3303 (3)	0.7159 (2)	1.0545 (2)	0.0533 (8)
H18A	0.3826	0.7603	1.0873	0.064*
C19	0.2665 (3)	0.71977 (19)	0.9567 (2)	0.0499 (8)
H19A	0.2765	0.7668	0.9225	0.060*
C20	0.1845 (3)	0.65347 (18)	0.9052 (2)	0.0395 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0786 (3)	0.0808 (3)	0.0568 (3)	−0.0023 (2)	0.0141 (2)	−0.0183 (2)
O1	0.0537 (13)	0.0915 (19)	0.0459 (14)	0.0005 (13)	0.0124 (11)	−0.0070 (13)
C1	0.049 (2)	0.055 (2)	0.054 (2)	0.0111 (16)	0.0221 (17)	0.0048 (16)
C2	0.0456 (19)	0.054 (2)	0.049 (2)	0.0120 (16)	0.0124 (16)	0.0006 (16)
C3	0.0442 (18)	0.060 (2)	0.053 (2)	0.0006 (16)	0.0131 (16)	−0.0032 (17)
C4	0.0430 (18)	0.058 (2)	0.060 (2)	0.0009 (16)	0.0223 (16)	0.0040 (17)
C5	0.0406 (17)	0.0422 (18)	0.055 (2)	0.0082 (15)	0.0182 (15)	0.0014 (15)
C6	0.051 (2)	0.053 (2)	0.055 (2)	0.0066 (17)	0.0208 (17)	−0.0032 (17)
C7	0.052 (2)	0.047 (2)	0.053 (2)	0.0073 (16)	0.0131 (17)	−0.0075 (16)
C8	0.051 (2)	0.048 (2)	0.069 (2)	0.0036 (16)	0.0162 (18)	−0.0050 (17)
C9	0.050 (2)	0.054 (2)	0.069 (2)	0.0040 (17)	0.0269 (18)	0.0024 (18)
C10	0.0386 (17)	0.0399 (18)	0.057 (2)	0.0070 (14)	0.0179 (15)	0.0027 (15)
C21	0.0451 (19)	0.072 (3)	0.073 (3)	0.0027 (18)	0.0160 (18)	−0.006 (2)
C22	0.0477 (19)	0.067 (2)	0.051 (2)	−0.0040 (18)	0.0116 (16)	0.0067 (17)
C23	0.0415 (18)	0.061 (2)	0.072 (2)	−0.0067 (17)	0.0090 (17)	−0.0002 (19)
C24	0.045 (2)	0.107 (3)	0.056 (2)	−0.016 (2)	0.0079 (17)	0.021 (2)
N1	0.0517 (17)	0.103 (3)	0.0512 (18)	−0.0028 (17)	0.0240 (14)	−0.0125 (18)
N2	0.0468 (15)	0.073 (2)	0.0480 (16)	−0.0084 (15)	0.0109 (13)	−0.0097 (15)
Br2	0.0957 (3)	0.0887 (3)	0.0446 (2)	−0.0178 (2)	0.0114 (2)	−0.00418 (19)
O2	0.0544 (13)	0.0687 (16)	0.0464 (14)	−0.0138 (12)	0.0064 (11)	0.0010 (11)
C11	0.0386 (17)	0.0419 (18)	0.0513 (19)	0.0011 (14)	0.0153 (15)	0.0094 (15)
C12	0.0347 (16)	0.047 (2)	0.0464 (19)	0.0035 (15)	0.0110 (14)	0.0000 (15)
C13	0.0427 (17)	0.0382 (18)	0.056 (2)	−0.0048 (14)	0.0095 (15)	−0.0056 (15)
C14	0.0477 (17)	0.0337 (17)	0.054 (2)	0.0003 (15)	0.0163 (15)	0.0046 (15)
C15	0.0359 (16)	0.0357 (17)	0.0458 (18)	0.0038 (13)	0.0141 (14)	0.0001 (14)
C16	0.0447 (18)	0.0460 (19)	0.049 (2)	0.0014 (15)	0.0182 (15)	0.0042 (15)
C17	0.0495 (18)	0.056 (2)	0.0416 (18)	0.0002 (16)	0.0151 (15)	−0.0034 (16)
C18	0.057 (2)	0.049 (2)	0.055 (2)	−0.0079 (16)	0.0181 (17)	−0.0094 (16)
C19	0.057 (2)	0.0390 (19)	0.054 (2)	−0.0082 (15)	0.0184 (17)	−0.0020 (15)
C20	0.0337 (15)	0.0402 (18)	0.0458 (18)	0.0044 (13)	0.0144 (14)	0.0004 (14)

Geometric parameters (Å, º)

Br1—C7	1.896 (3)	C23—C24	1.490 (5)
O1—C2	1.371 (4)	C23—H23A	0.9700
O1—H1B	0.8168	C23—H23B	0.9700
C1—C2	1.353 (4)	C24—N1	1.460 (5)
C1—C10	1.427 (4)	C24—H24A	0.9700
C1—H1A	0.9300	C24—H24B	0.9700
C2—C3	1.405 (4)	N1—H1C	0.8336
C3—C4	1.361 (4)	N2—H2A	0.7730
C3—H3A	0.9300	Br2—C17	1.903 (3)
C4—C5	1.392 (4)	O2—C12	1.360 (3)
C4—H4A	0.9300	O2—H2B	0.8329
C5—C10	1.423 (4)	C11—C12	1.369 (4)
C5—C6	1.431 (4)	C11—C20	1.408 (4)
C6—C7	1.338 (4)	C11—H11A	0.9300
C6—H6A	0.9300	C12—C13	1.403 (4)
C7—C8	1.414 (5)	C13—C14	1.367 (4)
C8—C9	1.355 (4)	C13—H13A	0.9300
C8—H8A	0.9300	C14—C15	1.409 (4)
C9—C10	1.406 (4)	C14—H14A	0.9300
C9—H9A	0.9300	C15—C16	1.406 (4)
C21—N1	1.470 (4)	C15—C20	1.420 (4)
C21—C22	1.495 (4)	C16—C17	1.356 (4)
C21—H21A	0.9700	C16—H16A	0.9300
C21—H21B	0.9700	C17—C18	1.398 (4)
C22—N2	1.468 (4)	C18—C19	1.350 (4)
C22—H22A	0.9700	C18—H18A	0.9300
C22—H22B	0.9700	C19—C20	1.419 (4)
C23—N2	1.464 (4)	C19—H19A	0.9300
C2—O1—H1B	106.3	N2—C23—H23B	109.8
C2—C1—C10	120.2 (3)	C24—C23—H23B	109.8
C2—C1—H1A	119.9	H23A—C23—H23B	108.2
C10—C1—H1A	119.9	N1—C24—C23	109.2 (3)
C1—C2—O1	118.7 (3)	N1—C24—H24A	109.8
C1—C2—C3	120.3 (3)	C23—C24—H24A	109.8
O1—C2—C3	121.0 (3)	N1—C24—H24B	109.8
C4—C3—C2	120.8 (3)	C23—C24—H24B	109.8
C4—C3—H3A	119.6	H24A—C24—H24B	108.3
C2—C3—H3A	119.6	C24—N1—C21	110.0 (3)
C3—C4—C5	120.7 (3)	C24—N1—H1C	116.5
C3—C4—H4A	119.6	C21—N1—H1C	99.4
C5—C4—H4A	119.6	C23—N2—C22	110.9 (3)
C4—C5—C10	119.1 (3)	C23—N2—H2A	112.0
C4—C5—C6	122.4 (3)	C22—N2—H2A	104.1
C10—C5—C6	118.4 (3)	C12—O2—H2B	107.6
C7—C6—C5	120.3 (3)	C12—C11—C20	121.1 (3)
C7—C6—H6A	119.9	C12—C11—H11A	119.5
C5—C6—H6A	119.9	C20—C11—H11A	119.5
C6—C7—C8	121.4 (3)	O2—C12—C11	119.3 (3)
C6—C7—Br1	120.6 (3)	O2—C12—C13	121.0 (3)
C8—C7—Br1	118.0 (3)	C11—C12—C13	119.8 (3)
C9—C8—C7	119.7 (3)	C14—C13—C12	120.3 (3)
C9—C8—H8A	120.1	C14—C13—H13A	119.9
C7—C8—H8A	120.1	C12—C13—H13A	119.9
C8—C9—C10	121.2 (3)	C13—C14—C15	121.5 (3)
C8—C9—H9A	119.4	C13—C14—H14A	119.3
C10—C9—H9A	119.4	C15—C14—H14A	119.3
C9—C10—C5	118.9 (3)	C16—C15—C14	122.3 (3)
C9—C10—C1	122.3 (3)	C16—C15—C20	119.7 (3)
C5—C10—C1	118.8 (3)	C14—C15—C20	118.1 (3)
N1—C21—C22	109.2 (3)	C17—C16—C15	119.6 (3)
N1—C21—H21A	109.9	C17—C16—H16A	120.2
C22—C21—H21A	109.9	C15—C16—H16A	120.2
N1—C21—H21B	109.9	C16—C17—C18	121.7 (3)
C22—C21—H21B	109.9	C16—C17—Br2	119.5 (2)
H21A—C21—H21B	108.3	C18—C17—Br2	118.7 (2)
N2—C22—C21	109.8 (3)	C19—C18—C17	119.7 (3)
N2—C22—H22A	109.7	C19—C18—H18A	120.1
C21—C22—H22A	109.7	C17—C18—H18A	120.1
N2—C22—H22B	109.7	C18—C19—C20	121.2 (3)
C21—C22—H22B	109.7	C18—C19—H19A	119.4
H22A—C22—H22B	108.2	C20—C19—H19A	119.4
N2—C23—C24	109.4 (3)	C11—C20—C19	122.8 (3)
N2—C23—H23A	109.8	C11—C20—C15	119.3 (3)
C24—C23—H23A	109.8	C19—C20—C15	117.9 (3)
C10—C1—C2—O1	178.7 (3)	C22—C21—N1—C24	−60.3 (4)
C10—C1—C2—C3	−1.9 (5)	C24—C23—N2—C22	58.6 (3)
C1—C2—C3—C4	1.6 (5)	C21—C22—N2—C23	−58.0 (3)
O1—C2—C3—C4	−179.0 (3)	C20—C11—C12—O2	−178.6 (2)
C2—C3—C4—C5	−0.3 (5)	C20—C11—C12—C13	−0.4 (4)
C3—C4—C5—C10	−0.7 (5)	O2—C12—C13—C14	176.8 (3)
C3—C4—C5—C6	−178.7 (3)	C11—C12—C13—C14	−1.3 (4)
C4—C5—C6—C7	178.1 (3)	C12—C13—C14—C15	1.4 (4)
C10—C5—C6—C7	0.1 (4)	C13—C14—C15—C16	179.6 (3)
C5—C6—C7—C8	1.0 (5)	C13—C14—C15—C20	0.2 (4)
C5—C6—C7—Br1	−177.5 (2)	C14—C15—C16—C17	−178.3 (3)
C6—C7—C8—C9	−1.5 (5)	C20—C15—C16—C17	1.2 (4)
Br1—C7—C8—C9	177.0 (2)	C15—C16—C17—C18	0.6 (5)
C7—C8—C9—C10	0.9 (5)	C15—C16—C17—Br2	−178.8 (2)
C8—C9—C10—C5	0.2 (5)	C16—C17—C18—C19	−1.7 (5)
C8—C9—C10—C1	−178.9 (3)	Br2—C17—C18—C19	177.7 (2)
C4—C5—C10—C9	−178.8 (3)	C17—C18—C19—C20	1.0 (5)
C6—C5—C10—C9	−0.7 (4)	C12—C11—C20—C19	−177.4 (3)
C4—C5—C10—C1	0.3 (4)	C12—C11—C20—C15	2.0 (4)
C6—C5—C10—C1	178.4 (3)	C18—C19—C20—C11	−179.7 (3)
C2—C1—C10—C9	−179.9 (3)	C18—C19—C20—C15	0.8 (4)
C2—C1—C10—C5	1.0 (4)	C16—C15—C20—C11	178.7 (3)
N1—C21—C22—N2	58.1 (4)	C14—C15—C20—C11	−1.9 (4)
N2—C23—C24—N1	−59.7 (4)	C16—C15—C20—C19	−1.8 (4)
C23—C24—N1—C21	61.2 (3)	C14—C15—C20—C19	177.6 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1B···N1	0.82	1.94	2.743 (4)	168
O2—H2B···N2^i	0.83	1.88	2.694 (4)	163
N1—H1C···O2	0.83	2.47	3.235 (4)	152
N2—H2A···O1^ii	0.77	2.50	3.184 (4)	149
C4—H4A···Cg5	0.93	2.77	3.471 (3)	133
C14—H14A···Cg2^iii	0.93	2.68	3.371 (3)	132
C16—H16A···Cg1^iii	0.93	2.90	3.570 (3)	130
C21—H21A···Cg2^iv	0.97	2.93	3.831 (3)	156

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