Dimethyl 3,3′-[(4,5-dicyano-1,2-phenyl­ene)bis­(­oxy)]dibenzoate

Bai, M.; Zhang, Y.; Zhang, C.

doi:10.1107/S1600536812027432

organic compounds

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ISSN: 2056-9890

Volume 68| Part 9| September 2012| Page o2611

doi:10.1107/S1600536812027432

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Dimethyl 3,3′-[(4,5-dicyano-1,2-phenylene)bis(oxy)]dibenzoate

Ming Bai,^a ^* Yan Zhang ^a and Chongxi Zhang ^a

^aMarine College, Shandong University at Weihai, Weihai 264209, People's Republic of China
^*Correspondence e-mail: ming_bai@sdu.edu.cn

(Received 13 June 2012; accepted 17 June 2012; online 1 August 2012)

In the title compound, C₂₄H₁₆N₂O₆, the dihedral angles between the central 4,5-dicyano-1,2-phenylene unit [maximum deviation from planarity = 0.014 (4) Å] and the pendant benzene rings are 73.62 (5) and 84.08 (6)°.

Related literature

For background to the properties and applications of phthalocyanines, see: Jiang & Ng (2009 ); Wang et al. (2011 ). For the synthesis, see Wang et al. (2009 ).

Experimental

Crystal data

C₂₄H₁₆N₂O₆
M_r = 428.39
Triclinic, $[P \overline 1]$
a = 10.1092 (11) Å
b = 10.3408 (11) Å
c = 10.8190 (14) Å
α = 82.284 (10)°
β = 85.991 (10)°
γ = 64.721 (11)°
V = 1013.3 (2) Å³
Z = 2
Cu Kα radiation
μ = 0.86 mm⁻¹
T = 293 K
0.15 × 0.11 × 0.08 mm

Data collection

Agilent Xcalibur Eos Gemini diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ) T_min = 0.882, T_max = 0.935
6668 measured reflections
3484 independent reflections
2790 reflections with I > 2σ(I)
R_int = 0.019

Refinement

R[F² > 2σ(F²)] = 0.039
wR(F²) = 0.119
S = 1.07
3484 reflections
292 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812027432/hb6852sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812027432/hb6852Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812027432/hb6852Isup3.cml

checkCIF report

Comment top

Phthalocyanines are a class of dye and pigments with a wide range of applications. Their macrocyclic basic unit contain four isoindole, which can complex with a range of metal ions. Large rare earth metal ions can bring together these tetrapyrrole derivatives to form sandwich-type double- and triple-decker complexes (Jiang et al., 2009). Depending on the metal centers and the nature of the macrocyclic ligands, these compounds exhibit tunable spectroscopic, electronic, and redox properties, and different extents of intramolecular π-π interactions. Some of the properties of the sandwich-type complexes are unique and enable them to be used as advanced materials for various applications (Wang et al., 2011). As an initial extension of our work on the substituent effect on the phthalocyanine properties, the title compound, as a precursor to synthesize phthalocyanine, was synthesized and characterized by X-ray diffraction, as shown in Fig. 1.

The compound (I) crystallizes in the triclinic system with only two molecule per unit cell, contains one 4,5-dicyano-1,2-phenylene C₈H₂N₂ as main framework and two 3-(methoxycarbonyl)phenolate C₈H₇O₃ substituents, and the C₈H₂N₂ framework is essentially flat, with the maximum deviation from the least-squares mean plane being 0.014 (4) Å. The dihedral angels between the C₈H₂N₂ unit and two benzene planes 3-(methoxycarbonyl)phenolate substituents are 73.62 (5) and 84.08 (6)°, respectively. As shown in Table 1, the C—C and C—O bond lengths within C₈H₂N₂ framework are not clear distinction, indicating the strongly delocalized π-system nature of the 4,5-dicyano-1,2-phenylene framework.

Related literature top

For background to the properties and applications of phthalocyanines, see: Jiang & Ng (2009); Wang et al. (2011). For the synthesis, see Wang et al. (2009).

Experimental top

On The basis of report lately(Wang et al., 2009), to a solution of methyl 3-hydroxybenzoate (3.04 g, 0.02 mol) and anhydrous Na₂CO₃ (4.20 g, 0.02 mol) in DMF(25 ml) stirred for 30 min, 4,5-dichlorophthalonitrile (0.98 g, 0.01 mol) was added. The resulting mixture was stirred at 60 ^oC for 48 h on the basis of TLC monitored. Then the mixture was poured into water (100 ml), and a slightly yellow solid was yielded and isolated by filtration. The crude product was dried in air, yielding dimethyl 3,3'-((4,5-dicyano-1,2-phenylene)bis(oxy))dibenzoate (2.08 g). The solid mixture was chromatographed on a silica gel column using CH₂Cl₃/hexane (1:1) as eluent. Repeated chromatography followed by recrystallization from CH₂Cl₃ and hexane gave the target compound as colorless blocks. Yield:1.98 g, 46%.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at 30% probability level.
	Fig. 2. Figure 2. A view of supramolecular configuration of (I).

Dimethyl 3,3'-[(4,5-dicyano-1,2-phenylene)bis(oxy)]dibenzoate top

Crystal data top

C₂₄H₁₆N₂O₆	Z = 2
M_r = 428.39	F(000) = 444
Triclinic, P1	D_x = 1.404 Mg m⁻³
Hall symbol: -P 1	Cu Kα radiation, λ = 1.54178 Å
a = 10.1092 (11) Å	Cell parameters from 3269 reflections
b = 10.3408 (11) Å	θ = 2.1–64.7°
c = 10.8190 (14) Å	µ = 0.86 mm⁻¹
α = 82.284 (10)°	T = 293 K
β = 85.991 (10)°	Block, colorless
γ = 64.721 (11)°	0.15 × 0.11 × 0.08 mm
V = 1013.3 (2) Å³

Data collection top

Agilent Xcalibur Eos Gemini diffractometer	3484 independent reflections
Radiation source: fine-focus sealed tube	2790 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.019
Detector resolution: 0 pixels mm^-1	θ_max = 66.0°, θ_min = 4.1°
ω scans	h = −11→11
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −9→12
T_min = 0.882, T_max = 0.935	l = −9→12
6668 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.039	H-atom parameters constrained
wR(F²) = 0.119	w = 1/[σ²(F_o²) + (0.063P)² + 0.0632P] where P = (F_o² + 2F_c²)/3
S = 1.07	(Δ/σ)_max = 0.010
3484 reflections	Δρ_max = 0.21 e Å⁻³
292 parameters	Δρ_min = −0.20 e Å⁻³
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0036 (6)

Crystal data top

C₂₄H₁₆N₂O₆	γ = 64.721 (11)°
M_r = 428.39	V = 1013.3 (2) Å³
Triclinic, P1	Z = 2
a = 10.1092 (11) Å	Cu Kα radiation
b = 10.3408 (11) Å	µ = 0.86 mm⁻¹
c = 10.8190 (14) Å	T = 293 K
α = 82.284 (10)°	0.15 × 0.11 × 0.08 mm
β = 85.991 (10)°

Data collection top

Agilent Xcalibur Eos Gemini diffractometer	3484 independent reflections
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	2790 reflections with I > 2σ(I)
T_min = 0.882, T_max = 0.935	R_int = 0.019
6668 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	1 restraint
wR(F²) = 0.119	H-atom parameters constrained
S = 1.07	Δρ_max = 0.21 e Å⁻³
3484 reflections	Δρ_min = −0.20 e Å⁻³
292 parameters

Special details top

Experimental. Absorption correction: CrysAlisPro, Agilent Technologies, Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET) (compiled Oct 27 2011,15:02:11) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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 (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.36679 (12)	0.87260 (13)	0.45190 (11)	0.0500 (3)
O2	0.53609 (14)	0.59249 (13)	0.39290 (10)	0.0547 (3)
O3	0.2830 (2)	0.7221 (2)	−0.11360 (13)	0.0933 (6)
O4	0.26548 (15)	0.56809 (16)	0.04354 (12)	0.0648 (4)
O5	−0.01163 (14)	0.88074 (16)	0.18060 (12)	0.0635 (4)
O6	−0.19904 (13)	0.89259 (17)	0.30884 (15)	0.0738 (4)
N1	1.0057 (2)	0.4624 (2)	0.7376 (2)	0.0809 (6)
N2	0.7608 (2)	0.8509 (2)	0.83423 (15)	0.0723 (5)
C1	0.75592 (17)	0.61523 (18)	0.63383 (14)	0.0447 (4)
C2	0.66927 (17)	0.75363 (18)	0.66704 (13)	0.0430 (4)
C3	0.53669 (17)	0.83798 (18)	0.60837 (14)	0.0450 (4)
H3	0.4778	0.9289	0.6315	0.054*
C4	0.49313 (17)	0.78577 (18)	0.51556 (14)	0.0432 (4)
C5	0.57990 (18)	0.64856 (18)	0.48157 (14)	0.0449 (4)
C6	0.71024 (19)	0.56367 (18)	0.54090 (15)	0.0479 (4)
H6	0.7675	0.4720	0.5187	0.058*
C7	0.51505 (17)	0.66227 (18)	0.27123 (14)	0.0449 (4)
C8	0.57881 (19)	0.7533 (2)	0.22567 (16)	0.0514 (4)
H8	0.6374	0.7728	0.2761	0.062*
C9	0.5536 (2)	0.8156 (2)	0.10261 (17)	0.0586 (5)
H9	0.5948	0.8783	0.0706	0.070*
C10	0.4682 (2)	0.7854 (2)	0.02736 (16)	0.0568 (5)
H10	0.4523	0.8275	−0.0550	0.068*
C11	0.40625 (18)	0.69222 (19)	0.07461 (15)	0.0482 (4)
C12	0.43022 (18)	0.62997 (18)	0.19734 (15)	0.0469 (4)
H12	0.3894	0.5669	0.2296	0.056*
C13	0.24755 (16)	0.83783 (17)	0.47464 (14)	0.0416 (4)
C14	0.21672 (18)	0.78724 (18)	0.59275 (15)	0.0491 (4)
H14	0.2801	0.7667	0.6583	0.059*
C15	0.0898 (2)	0.7680 (2)	0.61111 (17)	0.0587 (5)
H15	0.0671	0.7339	0.6899	0.070*
C16	−0.00390 (19)	0.7989 (2)	0.51367 (18)	0.0575 (5)
H16	−0.0905	0.7879	0.5277	0.069*
C17	0.02986 (17)	0.84627 (18)	0.39509 (16)	0.0469 (4)
C18	0.15724 (17)	0.86604 (17)	0.37489 (15)	0.0429 (4)
H18	0.1815	0.8977	0.2957	0.051*
C19	0.71881 (18)	0.8084 (2)	0.76095 (15)	0.0500 (4)
C20	0.8951 (2)	0.5287 (2)	0.69212 (18)	0.0556 (4)
C21	−0.07390 (18)	0.87628 (19)	0.29280 (18)	0.0537 (4)
C22	0.3129 (2)	0.6638 (2)	−0.00915 (16)	0.0563 (5)
C23	0.1746 (2)	0.5351 (3)	−0.0331 (2)	0.0756 (6)
H23A	0.0814	0.6165	−0.0446	0.113*
H23B	0.1605	0.4533	0.0073	0.113*
H23C	0.2215	0.5137	−0.1128	0.113*
C24	−0.1000 (3)	0.8966 (3)	0.0748 (2)	0.0795 (7)
H24A	−0.1324	0.8210	0.0842	0.119*
H24B	−0.0428	0.8913	−0.0006	0.119*
H24C	−0.1834	0.9882	0.0706	0.119*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0467 (6)	0.0577 (7)	0.0502 (6)	−0.0286 (6)	−0.0169 (5)	0.0096 (5)
O2	0.0801 (9)	0.0585 (7)	0.0403 (6)	−0.0430 (7)	−0.0184 (5)	0.0024 (5)
O3	0.1357 (15)	0.1149 (14)	0.0484 (8)	−0.0717 (12)	−0.0370 (9)	0.0116 (8)
O4	0.0720 (9)	0.0846 (10)	0.0503 (7)	−0.0426 (8)	−0.0150 (6)	−0.0085 (7)
O5	0.0553 (7)	0.0812 (9)	0.0595 (8)	−0.0331 (7)	−0.0194 (6)	−0.0020 (6)
O6	0.0421 (7)	0.0856 (10)	0.0996 (11)	−0.0272 (7)	−0.0076 (7)	−0.0257 (8)
N1	0.0627 (11)	0.0727 (12)	0.1003 (14)	−0.0196 (9)	−0.0356 (10)	0.0000 (10)
N2	0.0790 (12)	0.0964 (14)	0.0541 (9)	−0.0447 (11)	−0.0119 (8)	−0.0180 (9)
C1	0.0451 (9)	0.0530 (9)	0.0404 (8)	−0.0258 (8)	−0.0071 (6)	0.0011 (7)
C2	0.0454 (8)	0.0566 (9)	0.0331 (7)	−0.0273 (7)	−0.0041 (6)	−0.0034 (6)
C3	0.0462 (9)	0.0517 (9)	0.0400 (8)	−0.0233 (7)	−0.0017 (6)	−0.0052 (7)
C4	0.0443 (8)	0.0520 (9)	0.0374 (7)	−0.0257 (7)	−0.0096 (6)	0.0040 (6)
C5	0.0548 (9)	0.0540 (9)	0.0363 (8)	−0.0332 (8)	−0.0091 (7)	0.0003 (7)
C6	0.0546 (10)	0.0472 (9)	0.0444 (9)	−0.0230 (8)	−0.0073 (7)	−0.0047 (7)
C7	0.0479 (9)	0.0506 (9)	0.0374 (8)	−0.0214 (7)	−0.0064 (6)	−0.0035 (7)
C8	0.0511 (9)	0.0613 (10)	0.0504 (9)	−0.0318 (8)	−0.0033 (7)	−0.0063 (8)
C9	0.0630 (11)	0.0674 (12)	0.0525 (10)	−0.0370 (10)	0.0042 (8)	−0.0002 (8)
C10	0.0604 (11)	0.0681 (12)	0.0402 (9)	−0.0276 (9)	−0.0014 (7)	0.0012 (8)
C11	0.0484 (9)	0.0570 (10)	0.0386 (8)	−0.0209 (8)	−0.0031 (7)	−0.0067 (7)
C12	0.0512 (9)	0.0541 (9)	0.0403 (8)	−0.0265 (8)	−0.0048 (7)	−0.0050 (7)
C13	0.0391 (8)	0.0427 (8)	0.0440 (8)	−0.0178 (7)	−0.0048 (6)	−0.0047 (6)
C14	0.0530 (9)	0.0520 (10)	0.0395 (8)	−0.0195 (8)	−0.0034 (7)	−0.0040 (7)
C15	0.0596 (11)	0.0651 (11)	0.0501 (10)	−0.0279 (9)	0.0105 (8)	−0.0031 (8)
C16	0.0458 (9)	0.0620 (11)	0.0661 (11)	−0.0254 (9)	0.0077 (8)	−0.0076 (9)
C17	0.0407 (8)	0.0447 (9)	0.0557 (10)	−0.0169 (7)	−0.0034 (7)	−0.0094 (7)
C18	0.0418 (8)	0.0459 (8)	0.0423 (8)	−0.0199 (7)	−0.0046 (6)	−0.0030 (6)
C19	0.0508 (9)	0.0649 (11)	0.0396 (8)	−0.0286 (9)	−0.0041 (7)	−0.0064 (7)
C20	0.0548 (11)	0.0584 (11)	0.0580 (10)	−0.0272 (9)	−0.0146 (8)	−0.0024 (8)
C21	0.0429 (9)	0.0481 (9)	0.0723 (12)	−0.0185 (8)	−0.0101 (8)	−0.0124 (8)
C22	0.0604 (11)	0.0652 (11)	0.0419 (9)	−0.0232 (9)	−0.0091 (8)	−0.0087 (8)
C23	0.0767 (14)	0.0902 (16)	0.0725 (13)	−0.0414 (13)	−0.0213 (11)	−0.0192 (12)
C24	0.0740 (14)	0.0946 (17)	0.0736 (14)	−0.0367 (13)	−0.0357 (11)	−0.0003 (12)

Geometric parameters (Å, º) top

O1—C4	1.3746 (19)	C8—H8	0.9300
O1—C13	1.3956 (19)	C9—C10	1.379 (3)
O2—C5	1.3714 (19)	C9—H9	0.9300
O2—C7	1.3970 (19)	C10—C11	1.386 (3)
O3—C22	1.200 (2)	C10—H10	0.9300
O4—C22	1.323 (2)	C11—C12	1.385 (2)
O4—C23	1.449 (2)	C11—C22	1.491 (2)
O5—C21	1.332 (2)	C12—H12	0.9300
O5—C24	1.450 (2)	C13—C14	1.381 (2)
O6—C21	1.206 (2)	C13—C18	1.382 (2)
N1—C20	1.138 (2)	C14—C15	1.378 (3)
N2—C19	1.141 (2)	C14—H14	0.9300
C1—C6	1.388 (2)	C15—C16	1.379 (3)
C1—C2	1.403 (2)	C15—H15	0.9300
C1—C20	1.440 (2)	C16—C17	1.384 (3)
C2—C3	1.390 (2)	C16—H16	0.9300
C2—C19	1.440 (2)	C17—C18	1.386 (2)
C3—C4	1.380 (2)	C17—C21	1.488 (2)
C3—H3	0.9300	C18—H18	0.9300
C4—C5	1.396 (2)	C23—H23A	0.9600
C5—C6	1.378 (2)	C23—H23B	0.9600
C6—H6	0.9300	C23—H23C	0.9600
C7—C8	1.376 (2)	C24—H24A	0.9600
C7—C12	1.378 (2)	C24—H24B	0.9600
C8—C9	1.389 (3)	C24—H24C	0.9600

C4—O1—C13	117.31 (12)	C11—C12—H12	120.3
C5—O2—C7	118.67 (13)	C14—C13—C18	122.10 (15)
C22—O4—C23	115.98 (16)	C14—C13—O1	121.36 (14)
C21—O5—C24	116.20 (16)	C18—C13—O1	116.39 (13)
C6—C1—C2	119.92 (15)	C15—C14—C13	118.36 (16)
C6—C1—C20	119.81 (16)	C15—C14—H14	120.8
C2—C1—C20	120.21 (15)	C13—C14—H14	120.8
C3—C2—C1	119.98 (14)	C14—C15—C16	120.56 (16)
C3—C2—C19	120.20 (15)	C14—C15—H15	119.7
C1—C2—C19	119.82 (15)	C16—C15—H15	119.7
C4—C3—C2	119.47 (16)	C15—C16—C17	120.55 (17)
C4—C3—H3	120.3	C15—C16—H16	119.7
C2—C3—H3	120.3	C17—C16—H16	119.7
O1—C4—C3	119.52 (15)	C16—C17—C18	119.65 (16)
O1—C4—C5	119.78 (14)	C16—C17—C21	118.46 (16)
C3—C4—C5	120.62 (15)	C18—C17—C21	121.89 (16)
O2—C5—C6	118.30 (15)	C13—C18—C17	118.74 (15)
O2—C5—C4	121.55 (15)	C13—C18—H18	120.6
C6—C5—C4	120.09 (15)	C17—C18—H18	120.6
C5—C6—C1	119.90 (16)	N2—C19—C2	178.62 (18)
C5—C6—H6	120.0	N1—C20—C1	178.7 (2)
C1—C6—H6	120.0	O6—C21—O5	123.65 (17)
C8—C7—C12	121.66 (15)	O6—C21—C17	124.32 (18)
C8—C7—O2	122.68 (14)	O5—C21—C17	112.02 (14)
C12—C7—O2	115.61 (15)	O3—C22—O4	123.13 (18)
C7—C8—C9	118.44 (16)	O3—C22—C11	123.71 (19)
C7—C8—H8	120.8	O4—C22—C11	113.16 (15)
C9—C8—H8	120.8	O4—C23—H23A	109.5
C10—C9—C8	120.78 (18)	O4—C23—H23B	109.5
C10—C9—H9	119.6	H23A—C23—H23B	109.5
C8—C9—H9	119.6	O4—C23—H23C	109.5
C9—C10—C11	119.90 (16)	H23A—C23—H23C	109.5
C9—C10—H10	120.0	H23B—C23—H23C	109.5
C11—C10—H10	120.0	O5—C24—H24A	109.5
C12—C11—C10	119.81 (16)	O5—C24—H24B	109.5
C12—C11—C22	121.87 (16)	H24A—C24—H24B	109.5
C10—C11—C22	118.31 (16)	O5—C24—H24C	109.5
C7—C12—C11	119.39 (16)	H24A—C24—H24C	109.5
C7—C12—H12	120.3	H24B—C24—H24C	109.5

Experimental details

Crystal data
Chemical formula	C₂₄H₁₆N₂O₆
M_r	428.39
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	10.1092 (11), 10.3408 (11), 10.8190 (14)
α, β, γ (°)	82.284 (10), 85.991 (10), 64.721 (11)
V (Å³)	1013.3 (2)
Z	2
Radiation type	Cu Kα
µ (mm⁻¹)	0.86
Crystal size (mm)	0.15 × 0.11 × 0.08

Data collection
Diffractometer	Agilent Xcalibur Eos Gemini diffractometer
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2011)
T_min, T_max	0.882, 0.935
No. of measured, independent and observed [I > 2σ(I)] reflections	6668, 3484, 2790
R_int	0.019
(sin θ/λ)_max (Å⁻¹)	0.593

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.039, 0.119, 1.07
No. of reflections	3484
No. of parameters	292
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.21, −0.20

Computer programs: CrysAlis PRO (Agilent, 2011), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008).

Acknowledgements

Financial support from the National Natural Science Foundation of China, grant No. 21001069, is acknowledged.

References

Agilent (2011). CrysAlis PRO. Agilent Technolgies, Yanton, England. Google Scholar
Jiang, J. & Ng, D. K. P. (2009). Acc. Chem. Res. 42, 79–88. Web of Science CrossRef PubMed CAS Google Scholar
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