1,2-Bis[(2-hydr­oxy-3-methoxy­phenyl)­methyl­amino]benzene

Chen, Y.-F.; Ng, S.W.

doi:10.1107/S160053680702452X

1,2-Bis[(2-hydroxy-3-methoxyphenyl)methylamino]benzene

The title compound, C₂₂H₂₄N₂O₄, is a disubstituted α,α′-o-phenylenediamine whose hydroxyl groups engage in intermolecular O—H

N hydrogen bonding to form a chain. The amino groups have pyramidal configurations; their H atoms are not involved in any strong hydrogen-bonding interactions.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680702452X/hb2420sup1.cif Contains datablocks global, I
	Structure factor file (CIF format) https://doi.org/10.1107/S160053680702452X/hb2420Isup2.hkl Contains datablock I

CCDC reference: 651495

checkCIF report

Key indicators

Single-crystal X-ray study
T = 295 K
Mean (C-C) = 0.003 Å
R factor = 0.045
wR factor = 0.132
Data-to-parameter ratio = 16.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT416_ALERT_2_C Short Intra D-H..H-D       H1N    ..  H2N     ..       1.93 Ang.

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          4

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

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 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
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

Comment top

In this study, we synthesized the Schiff base, 1,2-bis(2-hydroxy-3-methoxybenzylideneamino)benzene, whose constitution is similar to that of the heterocyclic analog, 3,4-bis(2-hydroxy-3-methoxybenzylideneamino)pyridine, and whose structure we have recently reported (Bi et al., 2007). We then reduced the carbon–nitrogen double-bond of the Schiff base to form the title double-amine, which should function as a flexible tetradentate chelate in the formation of metal complexes.

For 1,2-bis(2-hydroxy-3-methoxybenzylideneamino)benzene Schiff base itself, the rigid nature is seen is the strained bond dimensions found in, for example, the manganese (Przychodzeń et al., 2005), cobalt (Wu et al., 2006) and copper (Salmon et al., 2005) complexes.

Related literature top

For related structures and background, see: Bi et al. (2007); Przychodzeń et al., (2005); Wu et al. (2006) and Salmon et al. (2006).

Experimental top

The precursor bis(3-methoxysalicylaldimine)-o-phenylene was prepared by condensing 3-methoxysalicylaldehyde with o-phenylenediamine. To a solution of the Schiff base (0.38 g, 1 mol) in methanol (80 ml) at room temperature was added solid potassium borohydride (0.27 g, 5 mol). The solution was stirred for several hours until the yellow color had disappeared. The solvent was removed and dichloromethane (50 ml) was added. A small amount of anhydrous sodium sulfate was added to remove traces of water. The colorless solution was dried to obtain a brown solid. This was purified by recrystallization from anhydrous methanol to give brown crystals of (I) in about 60% yield. CH&N elemental analysis. Calculated for C₂₂H₂₄N₂O₄: C 69.46, H 6.36, N 7.36; found: C 69.43, H 6.44, N 7.29%.

Structure description top

For related structures and background, see: Bi et al. (2007); Przychodzeń et al., (2005); Wu et al. (2006) and Salmon et al. (2006).

Computing details top

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2007).

Figures top

Fig. 1. View of (I) as a displacement ellipsoid plot (50% probability). Hydrogen atoms are drawn as spheres of arbitrary radius.

1,2-Bis[(2-hydroxy-3-methoxyphenyl)methylamino]benzene top

Crystal data top

C₂₂H₂₄N₂O₄	F(000) = 1616
M_r = 380.43	D_x = 1.306 Mg m⁻³
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 3418 reflections
a = 10.4665 (7) Å	θ = 2.6–21.5°
b = 15.778 (1) Å	µ = 0.09 mm⁻¹
c = 23.439 (2) Å	T = 295 K
V = 3870.8 (4) Å³	Block, brown
Z = 8	0.37 × 0.27 × 0.18 mm

Data collection top

Bruker APEX CCD area-detector diffractometer	2372 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.052
Graphite monochromator	θ_max = 27.5°, θ_min = 2.5°
φ and ω scans	h = −13→13
21495 measured reflections	k = −20→19
4411 independent reflections	l = −30→22

Refinement top

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.132	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	w = 1/[σ²(F_o²) + (0.0522P)² + 0.9447P] where P = (F_o² + 2F_c²)/3
4411 reflections	(Δ/σ)_max = 0.001
269 parameters	Δρ_max = 0.16 e Å⁻³
4 restraints	Δρ_min = −0.14 e Å⁻³

Crystal data top

C₂₂H₂₄N₂O₄	V = 3870.8 (4) Å³
M_r = 380.43	Z = 8
Orthorhombic, Pbca	Mo Kα radiation
a = 10.4665 (7) Å	µ = 0.09 mm⁻¹
b = 15.778 (1) Å	T = 295 K
c = 23.439 (2) Å	0.37 × 0.27 × 0.18 mm

Data collection top

Bruker APEX CCD area-detector diffractometer	2372 reflections with I > 2σ(I)
21495 measured reflections	R_int = 0.052
4411 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.045	4 restraints
wR(F²) = 0.132	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	Δρ_max = 0.16 e Å⁻³
4411 reflections	Δρ_min = −0.14 e Å⁻³
269 parameters

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.32120 (15)	0.66198 (11)	0.60670 (6)	0.0675 (5)
O2	0.36109 (14)	0.67543 (11)	0.71842 (7)	0.0606 (4)
O3	0.86678 (13)	0.46432 (10)	0.76967 (6)	0.0504 (4)
O4	1.08944 (13)	0.50169 (11)	0.81913 (6)	0.0674 (5)
N1	0.59204 (16)	0.65856 (11)	0.78926 (7)	0.0459 (4)
N2	0.59019 (15)	0.49037 (11)	0.81097 (7)	0.0426 (4)
C1	0.44971 (19)	0.70552 (13)	0.68120 (9)	0.0467 (5)
C2	0.4333 (2)	0.70033 (13)	0.62250 (9)	0.0504 (5)
C3	0.5247 (2)	0.73288 (15)	0.58635 (10)	0.0622 (6)
H3	0.5144	0.7293	0.5470	0.075*
C4	0.6333 (2)	0.77142 (17)	0.60961 (11)	0.0719 (7)
H4	0.6950	0.7942	0.5855	0.086*
C5	0.6496 (2)	0.77591 (15)	0.66762 (11)	0.0645 (7)
H5	0.7226	0.8012	0.6825	0.077*
C6	0.55805 (18)	0.74309 (13)	0.70423 (9)	0.0480 (5)
C7	0.2956 (3)	0.65090 (18)	0.54835 (10)	0.0794 (8)
H7A	0.2146	0.6231	0.5438	0.119*
H7B	0.3615	0.6168	0.5315	0.119*
H7C	0.2931	0.7052	0.5299	0.119*
C8	0.5692 (2)	0.74491 (13)	0.76782 (9)	0.0549 (6)
H8A	0.6393	0.7816	0.7789	0.066*
H8B	0.4912	0.7673	0.7843	0.066*
C9	0.54105 (17)	0.63253 (13)	0.84202 (8)	0.0439 (5)
C10	0.4937 (2)	0.68866 (16)	0.88249 (9)	0.0625 (6)
H10	0.4947	0.7467	0.8755	0.075*
C11	0.4449 (2)	0.65783 (19)	0.93341 (10)	0.0743 (8)
H11	0.4115	0.6954	0.9601	0.089*
C12	0.4452 (2)	0.57282 (19)	0.94485 (9)	0.0687 (7)
H12	0.4114	0.5527	0.9790	0.082*
C13	0.49600 (19)	0.51689 (15)	0.90553 (8)	0.0531 (5)
H13	0.4975	0.4592	0.9138	0.064*
C14	0.54468 (17)	0.54540 (13)	0.85409 (8)	0.0405 (5)
C15	0.65038 (19)	0.40989 (13)	0.82723 (9)	0.0483 (5)
H15A	0.6634	0.3760	0.7932	0.058*
H15B	0.5928	0.3790	0.8521	0.058*
C16	0.77694 (19)	0.42103 (12)	0.85726 (8)	0.0447 (5)
C17	0.7925 (2)	0.40482 (14)	0.91521 (9)	0.0590 (6)
H17	0.7243	0.3835	0.9362	0.071*
C18	0.9069 (3)	0.41991 (17)	0.94171 (10)	0.0749 (8)
H18	0.9159	0.4084	0.9804	0.090*
C19	1.0091 (2)	0.45205 (16)	0.91134 (10)	0.0684 (7)
H19	1.0864	0.4625	0.9297	0.082*
C20	0.9966 (2)	0.46862 (14)	0.85399 (9)	0.0524 (5)
C21	0.88098 (19)	0.45128 (12)	0.82675 (8)	0.0428 (5)
C22	1.2061 (2)	0.52865 (19)	0.84492 (11)	0.0809 (8)
H22A	1.2624	0.5504	0.8161	0.121*
H22B	1.2458	0.4814	0.8637	0.121*
H22C	1.1885	0.5723	0.8723	0.121*
H2O	0.2899 (16)	0.6617 (18)	0.7028 (11)	0.111 (11)*
H3O	0.9387 (14)	0.4747 (16)	0.7532 (9)	0.084 (9)*
H1N	0.5700 (19)	0.6231 (11)	0.7634 (7)	0.053 (6)*
H2N	0.6401 (15)	0.5163 (11)	0.7879 (7)	0.042 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0620 (10)	0.0901 (13)	0.0504 (9)	−0.0097 (9)	−0.0049 (8)	−0.0025 (8)
O2	0.0473 (9)	0.0791 (12)	0.0555 (10)	−0.0105 (8)	0.0002 (8)	0.0063 (8)
O3	0.0445 (8)	0.0652 (10)	0.0414 (8)	−0.0049 (8)	−0.0054 (7)	0.0027 (7)
O4	0.0427 (8)	0.1014 (14)	0.0581 (10)	−0.0082 (9)	−0.0091 (7)	−0.0113 (9)
N1	0.0495 (10)	0.0381 (10)	0.0501 (11)	0.0026 (8)	−0.0049 (8)	−0.0011 (8)
N2	0.0432 (9)	0.0437 (10)	0.0411 (10)	0.0003 (8)	0.0025 (8)	−0.0007 (8)
C1	0.0440 (11)	0.0421 (12)	0.0540 (13)	0.0062 (10)	0.0009 (10)	0.0054 (9)
C2	0.0465 (12)	0.0496 (13)	0.0552 (13)	0.0064 (10)	−0.0020 (10)	0.0029 (10)
C3	0.0634 (15)	0.0695 (17)	0.0539 (14)	0.0108 (13)	0.0049 (12)	0.0087 (12)
C4	0.0569 (14)	0.0809 (19)	0.0779 (18)	−0.0008 (13)	0.0124 (13)	0.0230 (14)
C5	0.0486 (13)	0.0611 (16)	0.0839 (18)	−0.0048 (11)	−0.0050 (12)	0.0166 (13)
C6	0.0447 (11)	0.0366 (11)	0.0627 (13)	0.0052 (9)	−0.0059 (10)	0.0077 (10)
C7	0.0802 (18)	0.105 (2)	0.0529 (15)	−0.0062 (16)	−0.0019 (13)	−0.0120 (14)
C8	0.0557 (13)	0.0400 (12)	0.0689 (15)	0.0010 (11)	−0.0137 (11)	−0.0005 (10)
C9	0.0380 (10)	0.0528 (13)	0.0409 (11)	0.0045 (9)	−0.0087 (9)	−0.0052 (9)
C10	0.0689 (15)	0.0640 (16)	0.0544 (14)	0.0181 (12)	−0.0107 (12)	−0.0135 (11)
C11	0.0770 (17)	0.096 (2)	0.0496 (15)	0.0328 (16)	−0.0064 (12)	−0.0218 (14)
C12	0.0580 (14)	0.107 (2)	0.0413 (13)	0.0199 (15)	0.0027 (11)	−0.0002 (13)
C13	0.0435 (11)	0.0702 (15)	0.0455 (12)	0.0044 (11)	−0.0001 (10)	0.0032 (11)
C14	0.0315 (9)	0.0523 (13)	0.0378 (10)	0.0039 (9)	−0.0067 (8)	−0.0036 (9)
C15	0.0513 (12)	0.0391 (12)	0.0546 (13)	−0.0032 (10)	0.0028 (10)	−0.0029 (9)
C16	0.0523 (12)	0.0354 (11)	0.0463 (12)	0.0069 (9)	−0.0020 (10)	−0.0015 (9)
C17	0.0664 (15)	0.0620 (15)	0.0487 (13)	0.0086 (12)	0.0052 (12)	0.0084 (11)
C18	0.0862 (19)	0.094 (2)	0.0442 (14)	0.0218 (16)	−0.0122 (14)	0.0050 (13)
C19	0.0602 (14)	0.0934 (19)	0.0515 (14)	0.0155 (14)	−0.0145 (12)	−0.0066 (13)
C20	0.0477 (12)	0.0617 (15)	0.0478 (12)	0.0077 (11)	−0.0072 (10)	−0.0092 (10)
C21	0.0482 (12)	0.0391 (11)	0.0409 (11)	0.0071 (9)	−0.0078 (9)	−0.0031 (9)
C22	0.0468 (13)	0.113 (2)	0.0827 (18)	−0.0067 (14)	−0.0139 (13)	−0.0261 (16)

Geometric parameters (Å, º) top

O1—C2	1.372 (3)	C8—H8A	0.9700
O1—C7	1.405 (3)	C8—H8B	0.9700
O2—C1	1.359 (2)	C9—C10	1.389 (3)
O2—H2O	0.858 (10)	C9—C14	1.404 (3)
O3—C21	1.362 (2)	C10—C11	1.387 (3)
O3—H3O	0.862 (10)	C10—H10	0.9300
O4—C20	1.373 (3)	C11—C12	1.368 (4)
O4—C22	1.427 (2)	C11—H11	0.9300
N1—C9	1.408 (2)	C12—C13	1.382 (3)
N1—C8	1.472 (3)	C12—H12	0.9300
N1—H1N	0.857 (9)	C13—C14	1.384 (3)
N2—C14	1.415 (2)	C13—H13	0.9300
N2—C15	1.468 (3)	C15—C16	1.510 (3)
N2—H2N	0.856 (9)	C15—H15A	0.9700
C1—C6	1.389 (3)	C15—H15B	0.9700
C1—C2	1.389 (3)	C16—C21	1.387 (3)
C2—C3	1.377 (3)	C16—C17	1.392 (3)
C3—C4	1.400 (3)	C17—C18	1.370 (3)
C3—H3	0.9300	C17—H17	0.9300
C4—C5	1.372 (3)	C18—C19	1.381 (3)
C4—H4	0.9300	C18—H18	0.9300
C5—C6	1.387 (3)	C19—C20	1.376 (3)
C5—H5	0.9300	C19—H19	0.9300
C6—C8	1.495 (3)	C20—C21	1.395 (3)
C7—H7A	0.9600	C22—H22A	0.9600
C7—H7B	0.9600	C22—H22B	0.9600
C7—H7C	0.9600	C22—H22C	0.9600

C2—O1—C7	118.78 (18)	C11—C10—H10	120.1
C1—O2—H2O	114 (2)	C9—C10—H10	120.1
C21—O3—H3O	111.9 (17)	C12—C11—C10	120.8 (2)
C20—O4—C22	117.84 (18)	C12—C11—H11	119.6
C9—N1—C8	120.56 (17)	C10—C11—H11	119.6
C9—N1—H1N	109.2 (14)	C11—C12—C13	119.8 (2)
C8—N1—H1N	108.6 (14)	C11—C12—H12	120.1
C14—N2—C15	119.34 (16)	C13—C12—H12	120.1
C14—N2—H2N	111.3 (13)	C12—C13—C14	121.0 (2)
C15—N2—H2N	108.4 (13)	C12—C13—H13	119.5
O2—C1—C6	117.19 (18)	C14—C13—H13	119.5
O2—C1—C2	122.08 (19)	C13—C14—C9	118.94 (18)
C6—C1—C2	120.7 (2)	C13—C14—N2	123.13 (19)
O1—C2—C3	126.3 (2)	C9—C14—N2	117.78 (17)
O1—C2—C1	113.52 (18)	N2—C15—C16	113.37 (16)
C3—C2—C1	120.1 (2)	N2—C15—H15A	108.9
C2—C3—C4	119.1 (2)	C16—C15—H15A	108.9
C2—C3—H3	120.5	N2—C15—H15B	108.9
C4—C3—H3	120.5	C16—C15—H15B	108.9
C5—C4—C3	120.6 (2)	H15A—C15—H15B	107.7
C5—C4—H4	119.7	C21—C16—C17	118.33 (19)
C3—C4—H4	119.7	C21—C16—C15	119.22 (17)
C4—C5—C6	120.6 (2)	C17—C16—C15	122.41 (19)
C4—C5—H5	119.7	C18—C17—C16	120.8 (2)
C6—C5—H5	119.7	C18—C17—H17	119.6
C5—C6—C1	118.9 (2)	C16—C17—H17	119.6
C5—C6—C8	123.8 (2)	C17—C18—C19	120.5 (2)
C1—C6—C8	117.36 (19)	C17—C18—H18	119.8
O1—C7—H7A	109.5	C19—C18—H18	119.8
O1—C7—H7B	109.5	C20—C19—C18	120.0 (2)
H7A—C7—H7B	109.5	C20—C19—H19	120.0
O1—C7—H7C	109.5	C18—C19—H19	120.0
H7A—C7—H7C	109.5	O4—C20—C19	125.9 (2)
H7B—C7—H7C	109.5	O4—C20—C21	114.60 (18)
N1—C8—C6	109.58 (17)	C19—C20—C21	119.5 (2)
N1—C8—H8A	109.8	O3—C21—C16	118.21 (17)
C6—C8—H8A	109.8	O3—C21—C20	120.97 (19)
N1—C8—H8B	109.8	C16—C21—C20	120.82 (18)
C6—C8—H8B	109.8	O4—C22—H22A	109.5
H8A—C8—H8B	108.2	O4—C22—H22B	109.5
C10—C9—C14	119.76 (19)	H22A—C22—H22B	109.5
C10—C9—N1	123.3 (2)	O4—C22—H22C	109.5
C14—C9—N1	116.89 (16)	H22A—C22—H22C	109.5
C11—C10—C9	119.7 (2)	H22B—C22—H22C	109.5

C7—O1—C2—C3	2.4 (3)	C12—C13—C14—N2	−175.84 (19)
C7—O1—C2—C1	−178.2 (2)	C10—C9—C14—C13	2.5 (3)
O2—C1—C2—O1	−0.4 (3)	N1—C9—C14—C13	179.80 (16)
C6—C1—C2—O1	−179.61 (18)	C10—C9—C14—N2	178.18 (17)
O2—C1—C2—C3	178.97 (19)	N1—C9—C14—N2	−4.5 (2)
C6—C1—C2—C3	−0.2 (3)	C15—N2—C14—C13	−32.3 (3)
O1—C2—C3—C4	178.9 (2)	C15—N2—C14—C9	152.26 (17)
C1—C2—C3—C4	−0.3 (3)	C14—N2—C15—C16	−67.7 (2)
C2—C3—C4—C5	0.8 (4)	N2—C15—C16—C21	−68.9 (2)
C3—C4—C5—C6	−0.6 (4)	N2—C15—C16—C17	108.8 (2)
C4—C5—C6—C1	0.1 (3)	C21—C16—C17—C18	1.2 (3)
C4—C5—C6—C8	179.5 (2)	C15—C16—C17—C18	−176.5 (2)
O2—C1—C6—C5	−178.86 (19)	C16—C17—C18—C19	0.4 (4)
C2—C1—C6—C5	0.4 (3)	C17—C18—C19—C20	−0.4 (4)
O2—C1—C6—C8	1.7 (3)	C22—O4—C20—C19	−6.0 (3)
C2—C1—C6—C8	−179.09 (18)	C22—O4—C20—C21	174.1 (2)
C9—N1—C8—C6	−145.63 (18)	C18—C19—C20—O4	178.9 (2)
C5—C6—C8—N1	−109.3 (2)	C18—C19—C20—C21	−1.2 (3)
C1—C6—C8—N1	70.2 (2)	C17—C16—C21—O3	177.79 (18)
C8—N1—C9—C10	−15.4 (3)	C15—C16—C21—O3	−4.4 (3)
C8—N1—C9—C14	167.46 (17)	C17—C16—C21—C20	−2.8 (3)
C14—C9—C10—C11	−3.0 (3)	C15—C16—C21—C20	174.97 (18)
N1—C9—C10—C11	179.90 (19)	O4—C20—C21—O3	2.1 (3)
C9—C10—C11—C12	1.4 (4)	C19—C20—C21—O3	−177.81 (19)
C10—C11—C12—C13	0.7 (4)	O4—C20—C21—C16	−177.26 (18)
C11—C12—C13—C14	−1.2 (3)	C19—C20—C21—C16	2.8 (3)
C12—C13—C14—C9	−0.4 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2O···N1ⁱ	0.86 (1)	2.08 (2)	2.834 (2)	146 (3)
O3—H3O···N2ⁱⁱ	0.86 (1)	2.20 (1)	3.035 (2)	163 (2)
N1—H1N···O2	0.86 (1)	2.56 (2)	2.945 (2)	108 (2)
N2—H2N···O3	0.86 (1)	2.55 (2)	3.080 (2)	121 (2)
N2—H2N···O4ⁱ	0.86 (1)	2.57 (2)	3.055 (2)	117 (2)

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

Experimental details

Crystal data
Chemical formula	C₂₂H₂₄N₂O₄
M_r	380.43
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	295
a, b, c (Å)	10.4665 (7), 15.778 (1), 23.439 (2)
V (Å³)	3870.8 (4)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.37 × 0.27 × 0.18

Data collection
Diffractometer	Bruker APEX CCD area-detector
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	21495, 4411, 2372
R_int	0.052
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.132, 0.99
No. of reflections	4411
No. of parameters	269
No. of restraints	4
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.16, −0.14

Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), X-SEED (Barbour, 2001), publCIF (Westrip, 2007).