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Acta Crystallogr Sect E Struct Rep Online. 2010 March 1; 66(Pt 3): o554.
Published online 2010 February 6. doi:  10.1107/S160053681000382X
PMCID: PMC2983753

Methyl 4-(2,7-dimeth­oxy-1-naphtho­yl)benzoate

Abstract

In the title compound, C21H18O5, the dihedral angle between the naphthalene ring system and the benzene ring is 86.65 (6)°. The bridging carbonyl C—C(=O)—C plane makes dihedral angles of 83.57 (7) and 20.21 (8)°, respectively, with the naphthalene ring system and the benzene ring. The ester O—C=O plane and the benzene ring are almost coplanar, making a dihedral angle of 3.81 (18)°. The two meth­oxy groups lie essentially in the naphthalene ring plane [C—O—C—C torsion angles = 2.1 (2) and −1.44 (19)°]. In the crystal structure, a centrosymmetric dimer is formed through C—H(...)O bonds connecting the 7-meth­oxy group and the carbonyl O atom of the ester group. The dimers are further linked by C—H(...)O hydrogen bonds between the methoxy­carbonyl group and the bridging carbonyl O atom.

Related literature

For electrophilic aromatic substitution of naphthalene derivatives, see: Okamoto & Yonezawa (2009 [triangle]). For the structures of closely related compounds, see: Mitsui, Nakaema, Noguchi et al. (2008 [triangle]); Mitsui, Nakaema, Noguchi & Yonezawa (2008 [triangle]); Mitsui et al. (2009 [triangle]); Watanabe et al. (2010 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-0o554-scheme1.jpg

Experimental

Crystal data

  • C21H18O5
  • M r = 350.35
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-0o554-efi1.jpg
  • a = 7.7714 (2) Å
  • b = 9.5195 (3) Å
  • c = 12.2737 (4) Å
  • α = 97.525 (2)°
  • β = 97.919 (2)°
  • γ = 106.630 (2)°
  • V = 847.73 (5) Å3
  • Z = 2
  • Cu Kα radiation
  • μ = 0.81 mm−1
  • T = 193 K
  • 0.40 × 0.20 × 0.05 mm

Data collection

  • Rigaku R-AXIS RAPID diffractometer
  • Absorption correction: numerical (NUMABS; Higashi, 1999 [triangle]) T min = 0.816, T max = 0.960
  • 15482 measured reflections
  • 3066 independent reflections
  • 2571 reflections with I > 2σ(I)
  • R int = 0.029

Refinement

  • R[F 2 > 2σ(F 2)] = 0.037
  • wR(F 2) = 0.117
  • S = 1.08
  • 3066 reflections
  • 239 parameters
  • H-atom parameters constrained
  • Δρmax = 0.24 e Å−3
  • Δρmin = −0.20 e Å−3

Data collection: PROCESS-AUTO (Rigaku, 1998 [triangle]); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004 [triangle]); program(s) used to solve structure: SIR2004 (Burla et al., 2005 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 [triangle]); software used to prepare material for publication: SHELXL97.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681000382X/is2518sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053681000382X/is2518Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors would express their gratitude to Professor Keiichi Noguchi for technical advice. This work was partially supported by the Iketani Science and Technology Foundation, Tokyo, Japan.

supplementary crystallographic information

Comment

In the course of our study on selective electrophilic aromatic aroylation of 2,7-dimethoxynaphthalene, peri-aroylnaphthalene compounds have proved to be formed regioselectively with the aid of suitable acidic mediator (Okamoto & Yonezawa, 2009). The aroyl groups at 1,8-positions of the naphthalene rings in these compounds are twisted almost perpendicularly but a little tiltedly toward exo sides against the naphthalene ring.

Recently, we have reported the X-ray crystal structures of several 1,8-diaroylated naphthalene homologues exemplified by bis(4-bromobenzoyl)(2,7-dimethoxynaphthalene-1,8-diyl)dimethanone (Watanabe et al., 2010). Furthermore, we have also clarified the crystal structures of 1-monoaroylated naphthalenes. 1-(4-Chlorobenzoyl)-2,7-dimethoxynaphthalene (Mitsui, Nakaema, Noguchi, Okamoto & Yonezawa, 2008) and (4-chlorobenzoyl)(2-ethoxy-7-methoxynaphthalen-1-yl)methanone (Mitsui et al., 2009) have essentially same non-coplanar structure as 1,8-diaroylated naphthalenes, and (4-chlorophenyl)(2-hydroxy-7-methoxynaphthalen-1-yl)methanone has substantially coplanar structure by intramolecular hydrogen bonding (Mitsui, Nakaema, Noguchi & Yonezawa, 2008). As a part of the course of our continuous study on the molecular structures of this kind of homologous molecules, the X-ray crystal structure of title compound, 1-monoaroylnaphthalene bearing ester group, is discussed in this report.

An ORTEPIII (Burnett & Johnson, 1996) plot of (I) is displayed in Fig. 1. In the molecule of (I), the interplanar angle between the benzene ring (C12—C17) and the naphthalene ring (C1—C10) is 86.65 (6)°. The dihedral angle between the ketonic C=O plane and the naphthalene ring is 83.57 (7)° [C10—C1—C11—O1 torsion angle = 84.41 (18)°]. The dihedral angle between the ketonic C=O plane and the benzene ring is 20.21 (8)° [C17—C12—C11—O1 torsion angle = 19.9 (2)°]. The torsion angle between the ketonic carbonyl group and benzene ring [C17—C12—C11—O1 torsion angle = 19.9 (2)°] is larger than that between the carbonyl moiety of ester group and the benzene ring [C14—C15—C20—O2 torsion angle = -4.0 (2)°]. Two methoxy groups lie essentially on the naphthalene ring plane. The methyl group on O4, which is a part of methoxy group adjacent to the aroyl group, is oriented to the exo site of the molecule and that on O5 is directed to endo site. In the crystal packing, molecules are aligned forming dimeric pairs. Each pair has two intermolecular C—H···O bonds therein: equivalent hydrogen bonds between a H atom of 7-methoxy group (H19B) and the O atom of carbonyl moiety in ester group (O2). There is another type of hydrogen bond between dimeric pairs: hydrogen bonds between a H atom of the methyl moiety in ester group (H21A) and the O atom of ketonic carbonyl group (O1) (Fig. 2 and Table 1).

Experimental

The title compound was prepared by regioselective electrophilic aromatic aroylation of 2,7-dimethoxynaphthalene with 4-(bromomethyl)benzoyl chloride followed by transformation of bromomethyl group. Single crystals suitable for X-ray diffraction were obtained by recrystallization from ethanol.

Spectroscopic Data: 1H NMR (300 MHz, CDCl3): δ3.73 (3H, s), 3.76 (3H, s), 3.94 (3H, s), 6.83 (1H, s), 7.01 (1H, d, J = 9.0 Hz), 7.14 (1H, d, J = 9.0 Hz), 7.71 (1H, d, J = 9.0 Hz), 7.87–7.90 (3H, m), 8.07 (2H, d, J = 8.1 Hz); 13C NMR (75.0 MHz, CDCl3): δ52.4, 55.2, 56.2, 101.9, 110.1, 117.2, 121.0, 124.4, 129.2, 129.7, 129.8, 131.6, 133.0, 133.9, 141.6, 155.4, 159.1, 166.4, 197.5; IR (KBr): 1674, 1625, 1511; m.p. = 154.6–157.1 °C; Anal. Calcd for C21H18O5: C 71.99, H 5.18%. Found: C 72.05, H 5.25%.

Refinement

All H atoms were found in a difference map and were subsequently refined as riding atoms, with C—H = 0.95 (aromatic) and 0.98 (methyl) Å, and with Uiso(H) = 1.2Ueq(C).

Figures

Fig. 1.
The molecular structure of (I), showing the atom-labeling scheme and 50% probability displacement ellipsoids.
Fig. 2.
A partial crystal packing diagram of compound (I). The intermolecular C—H···O interactions are shown as dashed lines.

Crystal data

C21H18O5Z = 2
Mr = 350.35F(000) = 368
Triclinic, P1Dx = 1.373 Mg m3
Hall symbol: -P 1Melting point = 427.6–430.1 K
a = 7.7714 (2) ÅCu Kα radiation, λ = 1.54187 Å
b = 9.5195 (3) ÅCell parameters from 10631 reflections
c = 12.2737 (4) Åθ = 3.7–68.2°
α = 97.525 (2)°µ = 0.81 mm1
β = 97.919 (2)°T = 193 K
γ = 106.630 (2)°Block, yellow
V = 847.73 (5) Å30.40 × 0.20 × 0.05 mm

Data collection

Rigaku R-AXIS RAPID diffractometer3066 independent reflections
Radiation source: rotating anode2571 reflections with I > 2σ(I)
graphiteRint = 0.029
Detector resolution: 10.00 pixels mm-1θmax = 68.2°, θmin = 3.7°
ω scansh = −9→9
Absorption correction: numerical (NUMABS; Higashi, 1999)k = −11→11
Tmin = 0.816, Tmax = 0.960l = −14→14
15482 measured reflections

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037H-atom parameters constrained
wR(F2) = 0.117w = 1/[σ2(Fo2) + (0.0674P)2 + 0.1365P] where P = (Fo2 + 2Fc2)/3
S = 1.08(Δ/σ)max < 0.001
3066 reflectionsΔρmax = 0.24 e Å3
239 parametersΔρmin = −0.20 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0056 (9)

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 (Å2)

xyzUiso*/Ueq
O11.18952 (13)0.98013 (12)0.33288 (8)0.0454 (3)
O20.76893 (17)0.46407 (13)0.65183 (9)0.0570 (3)
O30.59054 (13)0.32936 (11)0.49174 (8)0.0423 (3)
O40.76938 (14)1.00486 (13)0.26247 (8)0.0470 (3)
O51.29922 (14)0.59184 (12)0.00036 (9)0.0479 (3)
C10.94439 (17)0.87694 (14)0.17801 (11)0.0320 (3)
C20.80587 (18)0.93926 (15)0.16515 (12)0.0363 (3)
C30.7095 (2)0.93512 (17)0.05840 (12)0.0420 (4)
H30.61440.97940.05020.050*
C40.7548 (2)0.86624 (17)−0.03362 (12)0.0431 (4)
H40.68980.8635−0.10580.052*
C50.89479 (18)0.79937 (15)−0.02438 (11)0.0351 (3)
C60.9413 (2)0.72579 (16)−0.11830 (12)0.0426 (4)
H60.87800.7228−0.19100.051*
C71.0735 (2)0.65969 (16)−0.10717 (12)0.0439 (4)
H71.10120.6098−0.17150.053*
C81.17077 (19)0.66469 (15)0.00021 (12)0.0375 (3)
C91.13305 (18)0.73542 (15)0.09430 (11)0.0342 (3)
H91.19970.73830.16590.041*
C100.99256 (17)0.80497 (14)0.08386 (11)0.0326 (3)
C111.04313 (18)0.88600 (15)0.29455 (11)0.0334 (3)
C120.95508 (17)0.77299 (15)0.36010 (11)0.0328 (3)
C131.00721 (19)0.79937 (16)0.47627 (11)0.0370 (3)
H131.09700.88990.51340.044*
C140.92869 (19)0.69435 (16)0.53730 (11)0.0391 (3)
H140.96340.71330.61640.047*
C150.79879 (18)0.56076 (16)0.48323 (11)0.0352 (3)
C160.74621 (19)0.53386 (16)0.36727 (11)0.0370 (3)
H160.65730.44290.33010.044*
C170.82356 (18)0.63965 (15)0.30640 (11)0.0358 (3)
H170.78690.62140.22740.043*
C180.6225 (2)1.0673 (2)0.25460 (15)0.0519 (4)
H18A0.61111.10860.32970.062*
H18B0.50850.98950.21850.062*
H18C0.64721.14670.21010.062*
C191.4033 (2)0.59325 (18)0.10659 (13)0.0460 (4)
H19A1.48650.53440.09610.055*
H19B1.32030.55020.15530.055*
H19C1.47420.69610.14110.055*
C200.72025 (19)0.44915 (16)0.55271 (11)0.0381 (3)
C210.5110 (2)0.21403 (17)0.55273 (13)0.0466 (4)
H21A0.41220.13470.50200.056*
H21B0.46210.25680.61380.056*
H21C0.60510.17260.58350.056*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0398 (6)0.0492 (6)0.0360 (5)0.0012 (5)0.0004 (4)0.0041 (5)
O20.0752 (8)0.0539 (7)0.0302 (6)0.0028 (6)0.0075 (5)0.0079 (5)
O30.0465 (6)0.0410 (6)0.0352 (5)0.0071 (4)0.0065 (4)0.0075 (4)
O40.0489 (6)0.0594 (7)0.0394 (6)0.0285 (5)0.0095 (5)0.0043 (5)
O50.0547 (6)0.0520 (6)0.0406 (6)0.0230 (5)0.0140 (5)0.0008 (5)
C10.0331 (7)0.0312 (7)0.0297 (7)0.0068 (5)0.0052 (5)0.0061 (5)
C20.0357 (7)0.0351 (7)0.0363 (7)0.0084 (6)0.0066 (6)0.0063 (6)
C30.0391 (8)0.0460 (8)0.0414 (8)0.0157 (6)0.0006 (6)0.0116 (7)
C40.0450 (8)0.0437 (8)0.0349 (7)0.0074 (6)−0.0021 (6)0.0113 (6)
C50.0393 (7)0.0317 (7)0.0285 (7)0.0033 (6)0.0031 (5)0.0059 (5)
C60.0530 (9)0.0391 (8)0.0283 (7)0.0047 (7)0.0041 (6)0.0054 (6)
C70.0572 (9)0.0394 (8)0.0313 (7)0.0098 (7)0.0117 (6)0.0017 (6)
C80.0407 (7)0.0325 (7)0.0374 (7)0.0077 (6)0.0112 (6)0.0035 (6)
C90.0383 (7)0.0328 (7)0.0292 (7)0.0077 (6)0.0065 (5)0.0048 (5)
C100.0355 (7)0.0289 (7)0.0290 (7)0.0030 (5)0.0055 (5)0.0058 (5)
C110.0361 (7)0.0349 (7)0.0290 (7)0.0130 (6)0.0059 (5)0.0006 (5)
C120.0338 (7)0.0366 (7)0.0287 (7)0.0139 (6)0.0047 (5)0.0028 (5)
C130.0401 (7)0.0375 (7)0.0290 (7)0.0096 (6)0.0020 (5)0.0005 (6)
C140.0452 (8)0.0445 (8)0.0251 (6)0.0127 (6)0.0039 (5)0.0027 (6)
C150.0388 (7)0.0392 (8)0.0304 (7)0.0164 (6)0.0073 (5)0.0057 (6)
C160.0414 (7)0.0345 (7)0.0317 (7)0.0099 (6)0.0024 (6)0.0023 (6)
C170.0414 (7)0.0387 (8)0.0254 (6)0.0129 (6)0.0020 (5)0.0027 (6)
C180.0459 (9)0.0587 (10)0.0587 (10)0.0274 (8)0.0132 (7)0.0078 (8)
C190.0449 (8)0.0487 (9)0.0463 (9)0.0180 (7)0.0103 (6)0.0051 (7)
C200.0428 (8)0.0407 (8)0.0310 (7)0.0140 (6)0.0078 (6)0.0041 (6)
C210.0498 (9)0.0439 (9)0.0462 (9)0.0121 (7)0.0118 (7)0.0109 (7)

Geometric parameters (Å, °)

O1—C111.2154 (16)C9—C101.4298 (19)
O2—C201.2002 (17)C9—H90.9500
O3—C201.3368 (17)C11—C121.4933 (18)
O3—C211.4499 (17)C12—C171.3939 (19)
O4—C21.3772 (17)C12—C131.3960 (18)
O4—C181.4277 (18)C13—C141.381 (2)
O5—C81.3687 (17)C13—H130.9500
O5—C191.4327 (18)C14—C151.391 (2)
C1—C21.3708 (19)C14—H140.9500
C1—C101.4154 (19)C15—C161.3937 (19)
C1—C111.5065 (18)C15—C201.496 (2)
C2—C31.407 (2)C16—C171.3813 (19)
C3—C41.370 (2)C16—H160.9500
C3—H30.9500C17—H170.9500
C4—C51.408 (2)C18—H18A0.9800
C4—H40.9500C18—H18B0.9800
C5—C61.413 (2)C18—H18C0.9800
C5—C101.4231 (18)C19—H19A0.9800
C6—C71.351 (2)C19—H19B0.9800
C6—H60.9500C19—H19C0.9800
C7—C81.414 (2)C21—H21A0.9800
C7—H70.9500C21—H21B0.9800
C8—C91.3695 (19)C21—H21C0.9800
C20—O3—C21115.70 (11)C13—C12—C11119.85 (12)
C2—O4—C18118.25 (12)C14—C13—C12120.21 (13)
C8—O5—C19117.18 (11)C14—C13—H13119.9
C2—C1—C10120.65 (12)C12—C13—H13119.9
C2—C1—C11118.48 (12)C13—C14—C15120.17 (12)
C10—C1—C11120.86 (12)C13—C14—H14119.9
C1—C2—O4115.70 (12)C15—C14—H14119.9
C1—C2—C3121.08 (14)C14—C15—C16119.85 (13)
O4—C2—C3123.22 (13)C14—C15—C20118.23 (12)
C4—C3—C2118.99 (14)C16—C15—C20121.91 (12)
C4—C3—H3120.5C17—C16—C15119.91 (13)
C2—C3—H3120.5C17—C16—H16120.0
C3—C4—C5121.91 (13)C15—C16—H16120.0
C3—C4—H4119.0C16—C17—C12120.43 (12)
C5—C4—H4119.0C16—C17—H17119.8
C4—C5—C6122.64 (13)C12—C17—H17119.8
C4—C5—C10118.76 (13)O4—C18—H18A109.5
C6—C5—C10118.61 (13)O4—C18—H18B109.5
C7—C6—C5121.56 (13)H18A—C18—H18B109.5
C7—C6—H6119.2O4—C18—H18C109.5
C5—C6—H6119.2H18A—C18—H18C109.5
C6—C7—C8120.04 (14)H18B—C18—H18C109.5
C6—C7—H7120.0O5—C19—H19A109.5
C8—C7—H7120.0O5—C19—H19B109.5
O5—C8—C9124.51 (13)H19A—C19—H19B109.5
O5—C8—C7114.37 (12)O5—C19—H19C109.5
C9—C8—C7121.10 (14)H19A—C19—H19C109.5
C8—C9—C10119.48 (13)H19B—C19—H19C109.5
C8—C9—H9120.3O2—C20—O3123.51 (13)
C10—C9—H9120.3O2—C20—C15124.10 (13)
C1—C10—C5118.60 (13)O3—C20—C15112.39 (11)
C1—C10—C9122.18 (12)O3—C21—H21A109.5
C5—C10—C9119.20 (12)O3—C21—H21B109.5
O1—C11—C12121.49 (12)H21A—C21—H21B109.5
O1—C11—C1121.30 (12)O3—C21—H21C109.5
C12—C11—C1117.20 (11)H21A—C21—H21C109.5
C17—C12—C13119.41 (12)H21B—C21—H21C109.5
C17—C12—C11120.72 (11)
C10—C1—C2—O4179.30 (11)C6—C5—C10—C9−0.47 (18)
C11—C1—C2—O4−0.32 (18)C8—C9—C10—C1178.58 (11)
C10—C1—C2—C3−0.8 (2)C8—C9—C10—C5−0.08 (18)
C11—C1—C2—C3179.60 (12)C2—C1—C11—O1−98.98 (16)
C18—O4—C2—C1−177.96 (12)C10—C1—C11—O181.40 (17)
C18—O4—C2—C32.1 (2)C2—C1—C11—C1282.03 (15)
C1—C2—C3—C40.6 (2)C10—C1—C11—C12−97.59 (14)
O4—C2—C3—C4−179.50 (13)O1—C11—C12—C17−158.78 (14)
C2—C3—C4—C50.1 (2)C1—C11—C12—C1720.22 (18)
C3—C4—C5—C6178.96 (13)O1—C11—C12—C1319.9 (2)
C3—C4—C5—C10−0.5 (2)C1—C11—C12—C13−161.07 (12)
C4—C5—C6—C7−178.55 (13)C17—C12—C13—C14−0.2 (2)
C10—C5—C6—C70.9 (2)C11—C12—C13—C14−178.91 (12)
C5—C6—C7—C8−0.8 (2)C12—C13—C14—C150.8 (2)
C19—O5—C8—C9−1.44 (19)C13—C14—C15—C16−0.8 (2)
C19—O5—C8—C7179.73 (12)C13—C14—C15—C20178.81 (13)
C6—C7—C8—O5179.11 (12)C14—C15—C16—C170.2 (2)
C6—C7—C8—C90.2 (2)C20—C15—C16—C17−179.44 (13)
O5—C8—C9—C10−178.55 (11)C15—C16—C17—C120.5 (2)
C7—C8—C9—C100.2 (2)C13—C12—C17—C16−0.5 (2)
C2—C1—C10—C50.31 (19)C11—C12—C17—C16178.25 (12)
C11—C1—C10—C5179.92 (11)C21—O3—C20—O2−0.9 (2)
C2—C1—C10—C9−178.35 (12)C21—O3—C20—C15178.40 (12)
C11—C1—C10—C91.26 (19)C14—C15—C20—O2−4.0 (2)
C4—C5—C10—C10.33 (18)C16—C15—C20—O2175.62 (15)
C6—C5—C10—C1−179.18 (11)C14—C15—C20—O3176.73 (12)
C4—C5—C10—C9179.04 (11)C16—C15—C20—O3−3.64 (19)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C19—H19B···O2i0.982.573.461 (2)152
C21—H21A···O1ii0.982.493.4446 (19)163

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

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: IS2518).

References

  • Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst.38, 381–388.
  • Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII Report ORNL-6895. Oak Ridge National Laboratory. Tennessee, USA.
  • Higashi, T. (1999). NUMABS Rigaku Corporation, Tokyo, Japan.
  • Mitsui, R., Nakaema, K., Noguchi, K., Okamoto, A. & Yonezawa, N. (2008). Acta Cryst. E64, o1278. [PMC free article] [PubMed]
  • Mitsui, R., Nakaema, K., Noguchi, K. & Yonezawa, N. (2008). Acta Cryst. E64, o2497. [PMC free article] [PubMed]
  • Mitsui, R., Noguchi, K. & Yonezawa, N. (2009). Acta Cryst. E65, o543. [PMC free article] [PubMed]
  • Okamoto, A. & Yonezawa, N. (2009). Chem. Lett.38, 914–915.
  • Rigaku (1998). PROCESS-AUTO Rigaku Corporation, Tokyo, Japan.
  • Rigaku/MSC (2004). CrystalStructure Rigaku/MSC, The Woodlands, Texas, USA.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Watanabe, S., Nakaema, K., Muto, T., Okamoto, A. & Yonezawa, N. (2010). Acta Cryst. E66, o403. [PMC free article] [PubMed]

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