research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Crystal structure of benzyl 2-naphthyl ether, a sensitiser for thermal paper

aGraduate School of Environment and Information Sciences, Yokohama National University, Tokiwadai 79-7, Hodogaya-ku, Yokohama 240-8501, Japan, bFunctional Chemicals R&D Laboratories, Nippon Kayaku Corporation Limited, Shimo 3-31-2, Kita-ku, Tokyo 115-8588, Japan, and cColor Materials Division in Functional Chemicals Group, Nippon Kayaku Corporation Limited, Shimo 3-31-2, Kita-ku, Tokyo 115-8588, Japan
*Correspondence e-mail: matsumoto-shinya-py@ynu.ac.jp

Edited by H. Ishida, Okayama University, Japan (Received 3 December 2018; accepted 15 January 2019; online 18 January 2019)

The title compound [systematic name: 2-(benz­yloxy)naphthalene], C17H14O, which is used as a sensitiser for thermal paper, has a twisted conformation with a dihedral angle of 48.71 (12)° between the phenyl ring and the naphthyl ring system. In the crystal, one mol­ecule inter­acts with six neighbouring mol­ecules via inter­molecular C—H⋯π inter­actions to form a herringbone mol­ecular arrangement.

1. Chemical context

Thermal printing is a rapid and inexpensive printing technology widely used in commercial applications such as receipts, faxes and tickets (Gregory, 1991[Gregory, P. (1991). High-technology Applications of Organic Colorants. New York: Plenum Press.]; Mendum et al., 2011[Mendum, T., Stoler, E., VanBenschoten, H. & Warner, J. C. (2011). Green Chem. Lett. Rev. 4, 81-86.]). Many structural reports are available for thermosensitive dyes and developers (Matsumoto et al., 2010[Matsumoto, S., Takeshima, S., Satoh, S. & Kabashima, K. (2010). Dyes Pigments, 85, 139-142.]; Kodama et al., 2013[Kodama, S., Johmoto, K., Sekine, A., Fujii, K. & Uekusa, H. (2013). CrystEngComm, 15, 4667-4675.]; Gontani et al., 2017[Gontani, S., Ohashi, T., Miyanaga, K., Kurata, T., Akatani, Y. & Matsumoto, S. (2017). Dyes Pigments, 139, 549-555.]; Ohashi et al., 2017[Ohashi, T., Gontani, S., Miyanaga, K., Kurata, T., Akatani, Y. & Matsumoto, S. (2017). Dyes Pigments, 142, 198-200.]). On the other hand, we found only one report on the crystal structure of a compound commonly used as a sensitiser for the thermosensitive layer (Rudolph et al., 2010[Rudolph, F. A. M., Fuller, A. L., Slawin, A. M. Z., Bühl, M., Aitken, R. A. & Woollins, J. D. (2010). J. Chem. Crystallogr. 40, 253-265.]), which can facilitate the dye coloration process by lowering the melting point of the dye/developer composite on thermal paper (US EPA, 2014[US EPA (2014). Bisphenol A Alternative in Thermal Paper. Final report. United States Environmental Protection Agency.]). The title compound, benzyl 2-naphthyl ether, 1, is known as another commonly used sensitiser. Herein, we report the crystal structure of 1 as fundamental data for the investigation of its influence on the solid-state physicochemical properties of the thermosensitive layer of the thermal paper.

[Scheme 1]

2. Structural commentary

The title compound (Fig. 1[link]) is a simple ether compound in which a benzyl group is connected to a naphthyl group via an ether bond. The two aromatic rings are twisted, which is mainly attributable to the rotation about the C11—C12 bond. The dihedral angle between the mean planes of the naphthyl ring system (C1–C10) and the phenyl ring (C12–C17) is 48.71 (12)°. The related torsion angles for this dihedral angle are −44.9 (3)° (O1—C11—C12—C17), 178.7 (2)° (C1—O1—C11—C12) and −5.6 (3)° (C6—C1—O1—C11).

[Figure 1]
Figure 1
The mol­ecular structure of the title compound, 1, with displacement ellipsoids drawn at the 50% probability level.

3. Supra­molecular features

In the crystal, one mol­ecule inter­acts with six neighbouring mol­ecules via inter­molecular C—H⋯π inter­actions (Table 1[link]; Fig. 2[link]). The mol­ecules are linked by a C—H⋯π inter­action between the benzene C1–C6 rings (C3—H3⋯Cg1i; symmetry code as in Table 1[link]), forming a zigzag chain along the a-axis direction. The chains are connected into a layer structure parallel to the ab plane via a C—H⋯π inter­action between the benzene C4/C5/C7–C10 ring and the methyl­ene hydrogen atom (C11—H11ACg2ii; Table 1[link]). A weak C—H⋯π inter­action between the C12–C17 phenyl rings (C16—H16⋯Cg3iii; Table 1[link]) links the layers and thus the mol­ecules form a herringbone arrangement when viewed along the a axis, as shown in Fig. 3[link].

Table 1
Hydrogen-bond geometry (Å, °)

Cg1, Cg2 and Cg3 are the centroids of the C1–C6, C4/C5/C7–C10 and C12–C17 rings, respectively.

D—H⋯A D—H H⋯A DA D—H⋯A
C3—H3⋯Cg1i 0.93 2.71 3.439 (2) 135
C11—H11ACg2ii 0.97 2.63 3.512 (3) 150
C16—H16⋯Cg3iii 0.93 2.87 3.586 (3) 135
Symmetry codes: (i) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]; (ii) [x-{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+1]; (iii) [-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].
[Figure 2]
Figure 2
A packing diagram of the title compound, 1, showing inter­molecular C—H⋯π inter­actions (dashed lines). [Symmetry codes: (A) −x + 1, y + [{1\over 2}], −z + [{1\over 2}]; (B) −x + 1, y − [{1\over 2}], −z + [{1\over 2}]; (C) x + [{1\over 2}], −y + [{3\over 2}], −z + 1; (D) x − [{1\over 2}], −y + [{3\over 2}], −z + 1; (E) x + [{1\over 2}], −y + [{1\over 2}], −z + 1; (F) x − [{1\over 2}], −y + [{1\over 2}], −z + 1.]
[Figure 3]
Figure 3
A packing diagram of the title compound, 1, viewed along the a axis, showing a herringbone arrangement. H atoms have been omitted for clarity.

4. Database survey

Three analogous compounds of 1, namely, 2-benz­yloxy-1-naphthaldehyde, 2 [CSD (Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) refcode SOLVUL; Gao et al., 2009[Gao, R., Li, W.-H., Liu, P. & Wang, P.-A. (2009). Acta Cryst. E65, o534.]], 2-benz­yloxy-3-meth­oxy­naphthalene, 3 (MEBYIC; Huang et al., 2004[Huang, K.-S., Wang, E.-C. & Chen, H.-M. (2004). Jnl Chin. Chem. Soc. 51, 585-605.]) and 2-benz­yloxy-3-hy­droxy­naphthalene, 4 (SICGEQ; Peters et al., 1998[Peters, K., Peters, E.-M., Wuzik, A. & Bringmann, G. (1998). Z. Kristallogr. NCS213, 565-567.]), have been reported. Compounds, 2, 3 and 4, crystallize in the centrosymmetric space groups P21/c, P21/c and P[\overline{1}], respectively. Fig. 4[link] shows an overlay of the mol­ecular geometries of compounds 14, which indicates significant geometrical differences in the conformation of the benzyl unit caused by the rotations around the C1—O1 and C11—C12 bonds. Fig. 5[link] shows packing diagrams for compounds 24. In the crystals of 24, the mol­ecules form zigzag chains via C—H⋯O inter­actions. In 2, the chains are linked by ππ inter­actions into a three-dimensional network, whereas C—H⋯π inter­actions contribute to the arrangement of the chains in 3 and 4.

[Figure 4]
Figure 4
An overlay of the mol­ecular conformation of four analogous benzyl-2-naphthyl ether derivatives, 1 (blue), 2 (red), 3 (yellow) and 4 (green). All H atoms have been omitted for clarity.
[Figure 5]
Figure 5
Packing diagrams of compounds 2 (a), 3 (b) and 4 (c). The dotted lines indicate inter­molecular C—H⋯O and C—H⋯π inter­actions.

5. Synthesis and crystallization

The title compound was purchased from Tokyo Kasei Kogyo Co., Ltd., and used without further purification. X-ray diffraction quality colourless platelets were obtained using a liquid–liquid diffusion method, with combination of chloro­form and ethanol at 278 K.

6. Refinement

The crystal data, data collection and structure refinement details are summarized in Table 2[link]. All H atoms were positioned geometrically (C—H = 0.93 Å) and refined using a riding model with Uiso(H) = 1.2Ueq(C).

Table 2
Experimental details

Crystal data
Chemical formula C17H14O
Mr 234.30
Crystal system, space group Orthorhombic, P212121
Temperature (K) 298
a, b, c (Å) 6.10537 (10), 7.58687 (13), 26.8196 (5)
V3) 1242.30 (4)
Z 4
Radiation type Cu Kα
μ (mm−1) 0.59
Crystal size (mm) 0.61 × 0.42 × 0.04
 
Data collection
Diffractometer Rigaku XtaLAB PRO
Absorption correction Multi-scan (CrysAlis PRO; Rigaku OD, 2015[Rigaku Oxford Diffraction (2015). CrysAlis PRO. Rigaku Corporation, Tokyo, Japan.])
Tmin, Tmax 0.396, 0.976
No. of measured, independent and observed [F2 > 2.0σ(F2)] reflections 3724, 2017, 1841
Rint 0.033
(sin θ/λ)max−1) 0.594
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.042, 0.107, 1.01
No. of reflections 2017
No. of parameters 163
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.12, −0.20
Absolute structure Flack x determined using 601 quotients [(I+)−(I)]/[(I+)+(I)] (Parsons et al., 2013[Parsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249-259.])
Absolute structure parameter −0.3 (3)
Computer programs: CrysAlis PRO (Rigaku OD, 2015[Rigaku Oxford Diffraction (2015). CrysAlis PRO. Rigaku Corporation, Tokyo, Japan.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL2014 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]) and CrystalStructure (Rigaku, 2018[Rigaku (2018). CrystalStructure. Rigaku Corporation, Tokyo, Japan.]).

Supporting information


Computing details top

Data collection: CrysAlis PRO (Rigaku OD, 2015); cell refinement: CrysAlis PRO (Rigaku OD, 2015); data reduction: CrysAlis PRO (Rigaku OD, 2015); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: CrystalStructure (Rigaku, 2018); software used to prepare material for publication: CrystalStructure (Rigaku, 2018).

2-(Benzyloxy)naphthalene top
Crystal data top
C17H14ODx = 1.253 Mg m3
Mr = 234.30Cu Kα radiation, λ = 1.54184 Å
Orthorhombic, P212121Cell parameters from 2523 reflections
a = 6.10537 (10) Åθ = 6.1–71.1°
b = 7.58687 (13) ŵ = 0.59 mm1
c = 26.8196 (5) ÅT = 298 K
V = 1242.30 (4) Å3Plate, colourless
Z = 40.61 × 0.42 × 0.04 mm
F(000) = 496.00
Data collection top
Rigaku XtaLAB PRO
diffractometer
1841 reflections with F2 > 2.0σ(F2)
Detector resolution: 5.811 pixels mm-1Rint = 0.033
ω scansθmax = 66.4°, θmin = 3.3°
Absorption correction: multi-scan
(CrysAlis PRO; Rigaku OD, 2015)
h = 37
Tmin = 0.396, Tmax = 0.976k = 98
3724 measured reflectionsl = 3131
2017 independent reflections
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.042H-atom parameters constrained
wR(F2) = 0.107 w = 1/[σ2(Fo2) + (0.0559P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.01(Δ/σ)max < 0.001
2017 reflectionsΔρmax = 0.12 e Å3
163 parametersΔρmin = 0.20 e Å3
0 restraintsAbsolute structure: Flack x determined using 601 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.3 (3)
Secondary atom site location: difference Fourier map
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement was performed using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F2. R-factor (gt) are based on F. The threshold expression of F2 > 2.0 sigma(F2) is used only for calculating R-factor (gt).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.5853 (3)0.5557 (2)0.39703 (5)0.0492 (4)
C10.6358 (4)0.5250 (3)0.44606 (8)0.0394 (5)
C50.5738 (4)0.5198 (3)0.53498 (7)0.0380 (5)
C30.9115 (3)0.4027 (3)0.50010 (8)0.0432 (5)
H31.04880.35180.50450.052*
C40.7789 (4)0.4363 (3)0.54226 (8)0.0393 (5)
C120.3435 (4)0.6519 (3)0.33234 (8)0.0446 (5)
C60.5058 (3)0.5652 (3)0.48601 (8)0.0405 (5)
H60.37280.62230.48110.049*
C70.8415 (4)0.3848 (3)0.59097 (9)0.0494 (6)
H70.97600.33000.59600.059*
C20.8426 (4)0.4432 (3)0.45349 (9)0.0447 (5)
H20.93100.41730.42620.054*
C100.4399 (4)0.5505 (3)0.57705 (8)0.0466 (5)
H100.30600.60720.57310.056*
C110.3713 (4)0.6215 (4)0.38720 (8)0.0491 (6)
H11A0.34920.73130.40510.059*
H11B0.26280.53740.39870.059*
C80.7069 (5)0.4148 (4)0.63052 (9)0.0561 (6)
H80.74960.37980.66230.067*
C90.5047 (5)0.4980 (3)0.62363 (9)0.0547 (6)
H90.41360.51770.65090.066*
C130.1486 (4)0.6077 (4)0.30972 (9)0.0572 (6)
H130.04020.55090.32800.069*
C170.5030 (5)0.7337 (4)0.30452 (9)0.0557 (6)
H170.63650.76170.31920.067*
C160.4669 (6)0.7750 (4)0.25472 (10)0.0650 (8)
H160.57520.83150.23630.078*
C140.1122 (5)0.6472 (5)0.25993 (10)0.0721 (9)
H140.01950.61620.24490.086*
C150.2717 (5)0.7322 (4)0.23289 (10)0.0706 (9)
H150.24670.76070.19960.085*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0436 (8)0.0647 (10)0.0394 (8)0.0042 (7)0.0028 (7)0.0050 (7)
C10.0388 (11)0.0405 (11)0.0387 (11)0.0026 (9)0.0009 (9)0.0015 (8)
C50.0394 (11)0.0352 (10)0.0393 (11)0.0026 (8)0.0009 (9)0.0017 (9)
C30.0325 (9)0.0461 (11)0.0510 (13)0.0024 (9)0.0007 (11)0.0012 (10)
C40.0366 (10)0.0367 (10)0.0448 (11)0.0015 (9)0.0019 (10)0.0017 (9)
C120.0473 (12)0.0465 (11)0.0401 (11)0.0038 (10)0.0003 (10)0.0054 (9)
C60.0342 (10)0.0439 (11)0.0435 (11)0.0035 (8)0.0025 (10)0.0006 (9)
C70.0474 (12)0.0489 (12)0.0517 (13)0.0047 (11)0.0082 (12)0.0020 (10)
C20.0342 (10)0.0509 (12)0.0490 (12)0.0003 (9)0.0086 (10)0.0012 (10)
C100.0438 (12)0.0505 (12)0.0454 (12)0.0058 (10)0.0058 (11)0.0035 (10)
C110.0433 (12)0.0619 (14)0.0423 (12)0.0026 (11)0.0017 (10)0.0014 (10)
C80.0682 (16)0.0590 (14)0.0411 (12)0.0024 (13)0.0041 (13)0.0023 (11)
C90.0633 (15)0.0595 (14)0.0414 (12)0.0015 (13)0.0100 (12)0.0025 (11)
C130.0472 (12)0.0702 (16)0.0542 (14)0.0016 (12)0.0033 (12)0.0035 (12)
C170.0600 (14)0.0602 (15)0.0470 (13)0.0119 (12)0.0011 (13)0.0033 (11)
C160.085 (2)0.0626 (16)0.0473 (14)0.0058 (16)0.0077 (15)0.0040 (12)
C140.0624 (17)0.099 (2)0.0545 (16)0.0074 (17)0.0178 (15)0.0066 (16)
C150.092 (2)0.0753 (19)0.0444 (13)0.0178 (18)0.0101 (16)0.0030 (13)
Geometric parameters (Å, º) top
O1—C11.370 (2)C2—H20.9300
O1—C111.423 (3)C10—C91.370 (3)
C1—C61.368 (3)C10—H100.9300
C1—C21.421 (3)C11—H11A0.9700
C5—C101.413 (3)C11—H11B0.9700
C5—C41.417 (3)C8—C91.399 (4)
C5—C61.420 (3)C8—H80.9300
C3—C21.354 (3)C9—H90.9300
C3—C41.414 (3)C13—C141.387 (4)
C3—H30.9300C13—H130.9300
C4—C71.416 (3)C17—C161.390 (4)
C12—C171.374 (3)C17—H170.9300
C12—C131.377 (3)C16—C151.367 (4)
C12—C111.499 (3)C16—H160.9300
C6—H60.9300C14—C151.375 (4)
C7—C81.361 (4)C14—H140.9300
C7—H70.9300C15—H150.9300
C1—O1—C11116.36 (18)O1—C11—C12109.85 (19)
C6—C1—O1125.7 (2)O1—C11—H11A109.7
C6—C1—C2120.2 (2)C12—C11—H11A109.7
O1—C1—C2114.1 (2)O1—C11—H11B109.7
C10—C5—C4118.4 (2)C12—C11—H11B109.7
C10—C5—C6122.0 (2)H11A—C11—H11B108.2
C4—C5—C6119.61 (19)C7—C8—C9120.4 (2)
C2—C3—C4121.3 (2)C7—C8—H8119.8
C2—C3—H3119.4C9—C8—H8119.8
C4—C3—H3119.4C10—C9—C8120.4 (2)
C3—C4—C7122.2 (2)C10—C9—H9119.8
C3—C4—C5118.47 (19)C8—C9—H9119.8
C7—C4—C5119.3 (2)C12—C13—C14120.7 (3)
C17—C12—C13118.9 (2)C12—C13—H13119.7
C17—C12—C11121.5 (2)C14—C13—H13119.7
C13—C12—C11119.5 (2)C12—C17—C16120.8 (3)
C1—C6—C5120.1 (2)C12—C17—H17119.6
C1—C6—H6120.0C16—C17—H17119.6
C5—C6—H6120.0C15—C16—C17119.8 (3)
C8—C7—C4120.6 (2)C15—C16—H16120.1
C8—C7—H7119.7C17—C16—H16120.1
C4—C7—H7119.7C15—C14—C13119.7 (3)
C3—C2—C1120.3 (2)C15—C14—H14120.1
C3—C2—H2119.8C13—C14—H14120.1
C1—C2—H2119.8C16—C15—C14120.2 (3)
C9—C10—C5120.9 (2)C16—C15—H15119.9
C9—C10—H10119.5C14—C15—H15119.9
C5—C10—H10119.5
C11—O1—C1—C65.6 (3)C4—C5—C10—C91.2 (3)
C11—O1—C1—C2174.04 (19)C6—C5—C10—C9176.9 (2)
C2—C3—C4—C7175.9 (2)C1—O1—C11—C12178.72 (19)
C2—C3—C4—C52.3 (3)C17—C12—C11—O144.9 (3)
C10—C5—C4—C3178.9 (2)C13—C12—C11—O1139.5 (2)
C6—C5—C4—C30.8 (3)C4—C7—C8—C90.3 (4)
C10—C5—C4—C70.8 (3)C5—C10—C9—C80.9 (4)
C6—C5—C4—C7177.4 (2)C7—C8—C9—C100.1 (4)
O1—C1—C6—C5177.4 (2)C17—C12—C13—C140.8 (4)
C2—C1—C6—C52.2 (3)C11—C12—C13—C14174.9 (3)
C10—C5—C6—C1176.7 (2)C13—C12—C17—C161.4 (4)
C4—C5—C6—C11.4 (3)C11—C12—C17—C16174.2 (2)
C3—C4—C7—C8178.1 (2)C12—C17—C16—C150.7 (4)
C5—C4—C7—C80.0 (3)C12—C13—C14—C150.4 (4)
C4—C3—C2—C11.6 (3)C17—C16—C15—C140.6 (5)
C6—C1—C2—C30.7 (3)C13—C14—C15—C161.2 (5)
O1—C1—C2—C3178.9 (2)
Hydrogen-bond geometry (Å, º) top
Cg1, Cg2 and Cg3 are the centroids of the C1–C6, C4/C5/C7–C10 and C12–C17 rings, respectively.
D—H···AD—HH···AD···AD—H···A
C3—H3···Cg1i0.932.713.439 (2)135
C11—H11A···Cg2ii0.972.633.512 (3)150
C16—H16···Cg3iii0.932.873.586 (3)135
Symmetry codes: (i) x+1/2, y+1/2, z+1; (ii) x1/2, y+3/2, z+1; (iii) x+1, y+1/2, z+1/2.
 

References

First citationGao, R., Li, W.-H., Liu, P. & Wang, P.-A. (2009). Acta Cryst. E65, o534.  CrossRef IUCr Journals Google Scholar
First citationGontani, S., Ohashi, T., Miyanaga, K., Kurata, T., Akatani, Y. & Matsumoto, S. (2017). Dyes Pigments, 139, 549–555.  CrossRef CAS Google Scholar
First citationGregory, P. (1991). High-technology Applications of Organic Colorants. New York: Plenum Press.  Google Scholar
First citationGroom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179.  Web of Science CrossRef IUCr Journals Google Scholar
First citationHuang, K.-S., Wang, E.-C. & Chen, H.-M. (2004). Jnl Chin. Chem. Soc. 51, 585–605.  CrossRef CAS Google Scholar
First citationKodama, S., Johmoto, K., Sekine, A., Fujii, K. & Uekusa, H. (2013). CrystEngComm, 15, 4667–4675.  CrossRef CAS Google Scholar
First citationMatsumoto, S., Takeshima, S., Satoh, S. & Kabashima, K. (2010). Dyes Pigments, 85, 139–142.  CrossRef CAS Google Scholar
First citationMendum, T., Stoler, E., VanBenschoten, H. & Warner, J. C. (2011). Green Chem. Lett. Rev. 4, 81–86.  CrossRef CAS Google Scholar
First citationOhashi, T., Gontani, S., Miyanaga, K., Kurata, T., Akatani, Y. & Matsumoto, S. (2017). Dyes Pigments, 142, 198–200.  CrossRef CAS Google Scholar
First citationParsons, S., Flack, H. D. & Wagner, T. (2013). Acta Cryst. B69, 249–259.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationPeters, K., Peters, E.-M., Wuzik, A. & Bringmann, G. (1998). Z. Kristallogr. NCS213, 565–567.  Google Scholar
First citationRigaku (2018). CrystalStructure. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationRigaku Oxford Diffraction (2015). CrysAlis PRO. Rigaku Corporation, Tokyo, Japan.  Google Scholar
First citationRudolph, F. A. M., Fuller, A. L., Slawin, A. M. Z., Bühl, M., Aitken, R. A. & Woollins, J. D. (2010). J. Chem. Crystallogr. 40, 253–265.  CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2015a). Acta Cryst. A71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015b). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationUS EPA (2014). Bisphenol A Alternative in Thermal Paper. Final report. United States Environmental Protection Agency.  Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds