organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2414-3146

Di­ethyl (1-benzyl-4-phenyl-3-tri­fluoro­methyl-1H-pyrrol-2-yl)phospho­nate

aFaculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland, and bDepartment of Organic Chemistry, Faculty of Chemistry, University of Łodz, Tamka 12, 91-403 Łódz, Poland
*Correspondence e-mail: bzarychta@uni.opole.pl

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 29 July 2017; accepted 30 July 2017; online 8 August 2017)

In the title compound, C22H23F3NO3P, the dihedral angles between the pyrrole ring and the benzyl and phenyl rings are 81.38 (7) and 46.21 (8)°, respectively. The ethyl phosphate groups present with P—O—C—C torsion angles of −178.47 (10) and 106.72 (16)°, and an intra­molecular C—H⋯O hydrogen bond occurs. In the extended structure, mol­ecules are linked by C—H⋯O and C—H⋯F hydrogen bonds to generate [001] chains.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

Heterocycles bearing a tri­fluoro­methyl group have attracted much attention in pharmaceutical sciences as the introduction of fluorine atoms into an organic compound can cause enhancement and modification of their original physical, chemical and biological properties (e.g.: Gouverneur & Muller, 2012[Gouverneur, V. & Muller, K. (2012). Fluorine in Pharmaceutical and Medicinal Chemistry: From Biophysical Aspects to Clinical Applications, London: Imperial College Press.]; Zeng et al., 2014[Zeng, Q., Zhang, L., Yang, J., Xu, B., Xiao, Y. & Zhang, J. (2014). Chem. Commun. 50, 4203-4206.]). It has been also shown that the presence of a phosphonyl group can influence the biological functions of heterocyclic systems (e.g.: Dang et al., 2009[Dang, Q., Brown, B. S., Liu, Y., Rydzewski, R. M., Robinson, E. D., van Poelje, P. D., Reddy, M. R. & Erion, M. D. (2009). J. Med. Chem. 52, 2880-2898.]; Olszewski & Boduszek, 2010[Olszewski, T. K. & Boduszek, B. (2010). Tetrahedron, 66, 8661-8666.]). As part of our studies in this area, we now report the crystal structure of the title compound (Fig. 1[link]).

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

The dihedral angles between the pyrrole ring and the benzyl (N-bonded) and phenyl (C-bonded) rings are 81.38 (7) and 46.21 (8)°, respectively. The dihedral angle between the benzyl and phenyl aromatic rings amounts to 50.83 (5)°. The ethyl phosphate groups have different conformations: P1—O3—C1—C2 = −178.47 (10) and P1—O2—C3—C4 = 106.72 (16)°. The mol­ecular structure is stabilized by one intra­molecular weak hydrogen bond, i.e.: C16—H16A⋯O1 (Table 1[link]), which generates an S(6) ring.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C16—H16A⋯O2 0.97 2.35 3.1144 (16) 135
C8—H8⋯O1i 0.93 2.43 3.2148 (16) 142
C16—H16B⋯O1i 0.97 2.43 3.2178 (17) 138
C16—H16B⋯F1i 0.97 2.45 3.2224 (15) 136
Symmetry code: (i) [x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}].

In the extended structure, the mol­ecules are linked by C—H⋯O and C—H⋯F hydrogen bonds to generate [001] chains (Fig. 2[link]) in which O1 acts as a double acceptor.

[Figure 2]
Figure 2
The crystal packing of the title compound, viewed along the a axis showing C8—H8⋯O1i, C16—H16B⋯O1i and C16—H16B⋯F1i [symmetry code: (i) x, − y + [{1\over 2}], z + [{1\over 2}]] inter­molecular hydrogen bonds.

Synthesis and crystallization

The title compound was synthesized according to a procedure published previously (Cal & Zagórski, 2011[Cal, D. & Zagórski, P. (2011). Phosphorus Sulfur Silicon, 186, 2295-2302.]). Irregular colourless chunks of were recrystallized from a petroleum ether/Et2O 1:4 solution.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link].

Table 2
Experimental details

Crystal data
Chemical formula C22H23F3NO3P
Mr 437.38
Crystal system, space group Monoclinic, P21/c
Temperature (K) 150
a, b, c (Å) 13.7056 (3), 10.6494 (2), 14.9163 (3)
β (°) 91.744 (2)
V3) 2176.12 (8)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.17
Crystal size (mm) 0.27 × 0.20 × 0.15
 
Data collection
Diffractometer Oxford Diffraction Xcalibur
No. of measured, independent and observed [I > 2σ(I)] reflections 14420, 4254, 3251
Rint 0.019
(sin θ/λ)max−1) 0.617
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.079, 0.98
No. of reflections 4254
No. of parameters 271
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.32, −0.31
Computer programs: CrysAlis CCD (Oxford Diffraction, 2008[Oxford Diffraction (2008). CrysAlis CCD. Oxford Diffraction Ltd, Abingdon, England.]), SHELXS2014 (Sheldrick, 2015[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]a), SHELXL2014 (Sheldrick, 2015[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]b) and SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]).

Structural data


Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis CCD (Oxford Diffraction, 2008); data reduction: CrysAlis CCD (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015b).

Diethyl (1-benzyl-4-phenyl-3-trifluoromethyl-1H-pyrrol-2-yl)phosphonate top
Crystal data top
C22H23F3NO3PF(000) = 912
Mr = 437.38Dx = 1.335 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 13.7056 (3) ÅCell parameters from 14420 reflections
b = 10.6494 (2) Åθ = 3.0–26.0°
c = 14.9163 (3) ŵ = 0.17 mm1
β = 91.744 (2)°T = 150 K
V = 2176.12 (8) Å3Irregular, colourless
Z = 40.27 × 0.20 × 0.15 mm
Data collection top
Oxford Diffraction Xcalibur
diffractometer
3251 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.019
Detector resolution: 1024 x 1024 with blocks 2 x 2 pixels mm-1θmax = 26.0°, θmin = 3.0°
ω scanh = 1616
14420 measured reflectionsk = 1313
4254 independent reflectionsl = 1218
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.031H-atom parameters constrained
wR(F2) = 0.079 w = 1/[σ2(Fo2) + (0.0481P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.98(Δ/σ)max < 0.001
4254 reflectionsΔρmax = 0.32 e Å3
271 parametersΔρmin = 0.31 e Å3
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. All H atoms were found in a difference map but set to idealized positions and treated as riding atoms with CAr—H = 0.93 Å and Uiso(H) = 1.2Ueq(C) for C—H, with C—H3 = 0.96 Å and Uiso(H) = 1.5Ueq(C) and with C—H2 = 0.97 and Uiso(H) = 1.2Ueq(C).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N10.26227 (8)0.28475 (10)0.23073 (7)0.0171 (2)
O10.25503 (8)0.18705 (9)0.02572 (6)0.0291 (3)
O20.24039 (8)0.04337 (9)0.11152 (6)0.0278 (2)
O30.39528 (7)0.13043 (9)0.08712 (6)0.0263 (2)
P10.28542 (3)0.16327 (3)0.06738 (2)0.02047 (10)
F10.27999 (7)0.45000 (8)0.02257 (5)0.0319 (2)
F20.18429 (7)0.58775 (8)0.02989 (5)0.0386 (3)
F30.12551 (7)0.41436 (9)0.02136 (6)0.0409 (3)
C10.47105 (11)0.21634 (16)0.05827 (10)0.0327 (4)
H1A0.46400.29720.08730.039*
H1B0.46560.22870.00610.039*
C20.56792 (12)0.1603 (2)0.08338 (12)0.0469 (5)
H2A0.61890.21550.06500.070*
H2B0.57440.08060.05410.070*
H2C0.57270.14860.14720.070*
C30.13611 (13)0.01934 (17)0.10071 (12)0.0457 (5)
H3A0.10340.09430.07830.055*
H3B0.10960.00140.15840.055*
C40.11827 (18)0.0846 (2)0.03792 (16)0.0701 (7)
H4A0.04930.09930.03120.105*
H4B0.14970.15910.06070.105*
H4C0.14410.06370.01930.105*
C50.25575 (10)0.29234 (12)0.13827 (8)0.0172 (3)
C60.21315 (10)0.40874 (12)0.11826 (8)0.0170 (3)
C70.19250 (9)0.47038 (13)0.20012 (8)0.0173 (3)
C80.22526 (10)0.39073 (13)0.26700 (9)0.0188 (3)
H80.22250.40710.32810.023*
C90.20027 (11)0.46319 (13)0.02681 (9)0.0242 (3)
C100.13887 (10)0.58735 (13)0.21848 (9)0.0200 (3)
C110.05005 (11)0.61462 (14)0.17435 (10)0.0267 (3)
H110.02740.56300.12790.032*
C120.00447 (12)0.71717 (15)0.19877 (12)0.0363 (4)
H120.06330.73450.16860.044*
C130.02780 (14)0.79382 (17)0.26762 (12)0.0437 (5)
H130.00960.86220.28460.052*
C140.11546 (14)0.76936 (16)0.31135 (12)0.0433 (5)
H140.13760.82190.35740.052*
C150.17114 (12)0.66642 (15)0.28696 (10)0.0310 (4)
H150.23040.65050.31680.037*
C160.30577 (10)0.18449 (13)0.28608 (9)0.0196 (3)
H16A0.29480.10480.25590.023*
H16B0.27260.18130.34260.023*
C170.41387 (10)0.19995 (13)0.30541 (8)0.0197 (3)
C180.46153 (11)0.31409 (14)0.29963 (9)0.0251 (3)
H180.42720.38470.28000.030*
C190.56011 (12)0.32431 (15)0.32285 (10)0.0315 (4)
H190.59130.40160.31870.038*
C200.61174 (12)0.22048 (17)0.35194 (10)0.0339 (4)
H200.67780.22730.36730.041*
C210.56512 (12)0.10625 (16)0.35826 (11)0.0343 (4)
H210.59980.03600.37810.041*
C220.46686 (11)0.09576 (14)0.33519 (10)0.0271 (3)
H220.43600.01840.33960.033*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0182 (6)0.0208 (6)0.0122 (5)0.0017 (5)0.0011 (4)0.0016 (5)
O10.0432 (7)0.0281 (6)0.0156 (5)0.0017 (5)0.0035 (4)0.0029 (4)
O20.0356 (6)0.0217 (5)0.0259 (5)0.0050 (5)0.0030 (5)0.0010 (4)
O30.0274 (6)0.0254 (6)0.0262 (5)0.0054 (4)0.0026 (4)0.0006 (4)
P10.0273 (2)0.01945 (19)0.01456 (18)0.00111 (16)0.00119 (14)0.00163 (14)
F10.0448 (6)0.0329 (5)0.0183 (4)0.0001 (4)0.0085 (4)0.0028 (4)
F20.0683 (7)0.0245 (5)0.0230 (4)0.0135 (5)0.0022 (4)0.0064 (4)
F30.0426 (6)0.0514 (6)0.0273 (5)0.0019 (5)0.0215 (4)0.0024 (4)
C10.0307 (9)0.0403 (10)0.0272 (8)0.0023 (7)0.0034 (7)0.0030 (7)
C20.0302 (10)0.0725 (14)0.0380 (10)0.0048 (9)0.0000 (8)0.0055 (9)
C30.0437 (11)0.0435 (11)0.0497 (11)0.0130 (9)0.0002 (9)0.0068 (9)
C40.0680 (16)0.0592 (14)0.0819 (16)0.0233 (12)0.0168 (13)0.0115 (12)
C50.0163 (7)0.0221 (7)0.0130 (6)0.0012 (6)0.0021 (5)0.0003 (5)
C60.0155 (7)0.0196 (7)0.0158 (6)0.0017 (6)0.0030 (5)0.0005 (5)
C70.0134 (7)0.0208 (7)0.0177 (7)0.0010 (6)0.0007 (5)0.0009 (5)
C80.0188 (7)0.0240 (7)0.0135 (6)0.0013 (6)0.0003 (5)0.0024 (5)
C90.0326 (9)0.0226 (8)0.0172 (7)0.0032 (7)0.0041 (6)0.0004 (6)
C100.0197 (7)0.0210 (7)0.0196 (7)0.0003 (6)0.0026 (6)0.0016 (6)
C110.0237 (8)0.0243 (8)0.0320 (8)0.0024 (6)0.0024 (6)0.0007 (6)
C120.0261 (9)0.0325 (9)0.0502 (10)0.0097 (7)0.0015 (8)0.0004 (8)
C130.0434 (11)0.0346 (10)0.0537 (11)0.0163 (8)0.0094 (9)0.0074 (8)
C140.0542 (12)0.0363 (10)0.0393 (10)0.0084 (9)0.0005 (9)0.0182 (8)
C150.0321 (9)0.0328 (9)0.0278 (8)0.0052 (7)0.0044 (7)0.0072 (7)
C160.0250 (8)0.0195 (7)0.0141 (6)0.0021 (6)0.0018 (6)0.0033 (5)
C170.0241 (8)0.0239 (8)0.0110 (6)0.0037 (6)0.0000 (5)0.0019 (5)
C180.0268 (8)0.0247 (8)0.0235 (7)0.0026 (6)0.0030 (6)0.0034 (6)
C190.0290 (9)0.0350 (9)0.0303 (8)0.0061 (7)0.0024 (7)0.0000 (7)
C200.0222 (8)0.0503 (11)0.0290 (9)0.0055 (8)0.0042 (7)0.0063 (7)
C210.0298 (9)0.0367 (10)0.0359 (9)0.0140 (8)0.0064 (7)0.0003 (8)
C220.0301 (9)0.0220 (8)0.0290 (8)0.0055 (7)0.0025 (7)0.0008 (6)
Geometric parameters (Å, º) top
N1—C81.3567 (17)C7—C101.4763 (19)
N1—C51.3817 (16)C8—H80.9300
N1—C161.4654 (16)C10—C151.386 (2)
O1—P11.4598 (10)C10—C111.3966 (19)
O2—C31.456 (2)C11—C121.379 (2)
O2—P11.5715 (10)C11—H110.9300
O3—C11.4586 (18)C12—C131.374 (2)
O3—P11.5650 (10)C12—H120.9300
P1—C51.7886 (14)C13—C141.374 (2)
F1—C91.3436 (17)C13—H130.9300
F2—C91.3455 (16)C14—C151.390 (2)
F3—C91.3385 (16)C14—H140.9300
C1—C21.493 (2)C15—H150.9300
C1—H1A0.9700C16—C171.5097 (19)
C1—H1B0.9700C16—H16A0.9700
C2—H2A0.9600C16—H16B0.9700
C2—H2B0.9600C17—C181.384 (2)
C2—H2C0.9600C17—C221.392 (2)
C3—C41.466 (3)C18—C191.389 (2)
C3—H3A0.9700C18—H180.9300
C3—H3B0.9700C19—C201.376 (2)
C4—H4A0.9600C19—H190.9300
C4—H4B0.9600C20—C211.379 (2)
C4—H4C0.9600C20—H200.9300
C5—C61.3987 (18)C21—C221.384 (2)
C6—C71.4223 (18)C21—H210.9300
C6—C91.4877 (18)C22—H220.9300
C7—C81.3745 (18)
C8—N1—C5109.62 (11)F3—C9—F2106.18 (11)
C8—N1—C16122.15 (10)F1—C9—F2104.94 (11)
C5—N1—C16128.16 (11)F3—C9—C6114.09 (12)
C3—O2—P1119.54 (10)F1—C9—C6112.71 (11)
C1—O3—P1119.59 (9)F2—C9—C6111.58 (11)
O1—P1—O3117.57 (6)C15—C10—C11118.37 (13)
O1—P1—O2115.80 (6)C15—C10—C7120.00 (12)
O3—P1—O297.32 (6)C11—C10—C7121.31 (12)
O1—P1—C5111.45 (6)C12—C11—C10120.79 (14)
O3—P1—C5107.17 (6)C12—C11—H11119.6
O2—P1—C5106.11 (6)C10—C11—H11119.6
O3—C1—C2108.10 (13)C13—C12—C11120.21 (15)
O3—C1—H1A110.1C13—C12—H12119.9
C2—C1—H1A110.1C11—C12—H12119.9
O3—C1—H1B110.1C12—C13—C14119.93 (16)
C2—C1—H1B110.1C12—C13—H13120.0
H1A—C1—H1B108.4C14—C13—H13120.0
C1—C2—H2A109.5C13—C14—C15120.26 (16)
C1—C2—H2B109.5C13—C14—H14119.9
H2A—C2—H2B109.5C15—C14—H14119.9
C1—C2—H2C109.5C10—C15—C14120.43 (15)
H2A—C2—H2C109.5C10—C15—H15119.8
H2B—C2—H2C109.5C14—C15—H15119.8
O2—C3—C4110.34 (16)N1—C16—C17114.09 (11)
O2—C3—H3A109.6N1—C16—H16A108.7
C4—C3—H3A109.6C17—C16—H16A108.7
O2—C3—H3B109.6N1—C16—H16B108.7
C4—C3—H3B109.6C17—C16—H16B108.7
H3A—C3—H3B108.1H16A—C16—H16B107.6
C3—C4—H4A109.5C18—C17—C22118.52 (14)
C3—C4—H4B109.5C18—C17—C16123.11 (12)
H4A—C4—H4B109.5C22—C17—C16118.27 (13)
C3—C4—H4C109.5C17—C18—C19120.72 (14)
H4A—C4—H4C109.5C17—C18—H18119.6
H4B—C4—H4C109.5C19—C18—H18119.6
N1—C5—C6106.19 (11)C20—C19—C18120.18 (15)
N1—C5—P1122.43 (10)C20—C19—H19119.9
C6—C5—P1130.99 (10)C18—C19—H19119.9
C5—C6—C7108.57 (11)C19—C20—C21119.72 (15)
C5—C6—C9125.33 (12)C19—C20—H20120.1
C7—C6—C9125.88 (12)C21—C20—H20120.1
C8—C7—C6105.62 (11)C20—C21—C22120.24 (15)
C8—C7—C10122.65 (12)C20—C21—H21119.9
C6—C7—C10131.45 (12)C22—C21—H21119.9
N1—C8—C7109.98 (11)C21—C22—C17120.62 (15)
N1—C8—H8125.0C21—C22—H22119.7
C7—C8—H8125.0C17—C22—H22119.7
F3—C9—F1106.69 (11)
C1—O3—P1—O155.83 (12)C5—C6—C9—F377.75 (18)
C1—O3—P1—O2179.97 (10)C7—C6—C9—F3108.26 (15)
C1—O3—P1—C570.55 (11)C5—C6—C9—F144.13 (18)
C3—O2—P1—O146.40 (13)C7—C6—C9—F1129.86 (14)
C3—O2—P1—O3171.88 (11)C5—C6—C9—F2161.91 (13)
C3—O2—P1—C577.82 (12)C7—C6—C9—F212.1 (2)
P1—O3—C1—C2178.47 (11)C8—C7—C10—C1544.5 (2)
P1—O2—C3—C4106.72 (16)C6—C7—C10—C15142.47 (15)
C8—N1—C5—C60.25 (14)C8—C7—C10—C11128.81 (15)
C16—N1—C5—C6176.76 (13)C6—C7—C10—C1144.2 (2)
C8—N1—C5—P1173.24 (10)C15—C10—C11—C120.5 (2)
C16—N1—C5—P19.75 (19)C7—C10—C11—C12173.01 (14)
O1—P1—C5—N1169.14 (10)C10—C11—C12—C130.4 (2)
O3—P1—C5—N160.93 (12)C11—C12—C13—C141.0 (3)
O2—P1—C5—N142.25 (12)C12—C13—C14—C150.8 (3)
O1—P1—C5—C62.57 (15)C11—C10—C15—C140.7 (2)
O3—P1—C5—C6127.36 (13)C7—C10—C15—C14172.85 (14)
O2—P1—C5—C6129.45 (13)C13—C14—C15—C100.1 (3)
N1—C5—C6—C71.00 (15)C8—N1—C16—C1789.45 (15)
P1—C5—C6—C7171.72 (11)C5—N1—C16—C1787.23 (16)
N1—C5—C6—C9173.87 (12)N1—C16—C17—C1821.10 (18)
P1—C5—C6—C913.4 (2)N1—C16—C17—C22162.55 (12)
C5—C6—C7—C81.35 (15)C22—C17—C18—C190.1 (2)
C9—C6—C7—C8173.48 (13)C16—C17—C18—C19176.48 (12)
C5—C6—C7—C10172.52 (13)C17—C18—C19—C200.1 (2)
C9—C6—C7—C1012.7 (2)C18—C19—C20—C210.2 (2)
C5—N1—C8—C70.62 (15)C19—C20—C21—C220.2 (2)
C16—N1—C8—C7177.85 (12)C20—C21—C22—C170.0 (2)
C6—C7—C8—N11.20 (15)C18—C17—C22—C210.2 (2)
C10—C7—C8—N1173.34 (12)C16—C17—C22—C21176.68 (13)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C16—H16A···O20.972.353.1144 (16)135
C8—H8···O1i0.932.433.2148 (16)142
C16—H16B···O1i0.972.433.2178 (17)138
C16—H16B···F1i0.972.453.2224 (15)136
Symmetry code: (i) x, y+1/2, z+1/2.
 

References

First citationCal, D. & Zagórski, P. (2011). Phosphorus Sulfur Silicon, 186, 2295–2302.  Web of Science CrossRef CAS Google Scholar
First citationDang, Q., Brown, B. S., Liu, Y., Rydzewski, R. M., Robinson, E. D., van Poelje, P. D., Reddy, M. R. & Erion, M. D. (2009). J. Med. Chem. 52, 2880–2898.  Web of Science CrossRef PubMed CAS Google Scholar
First citationGouverneur, V. & Muller, K. (2012). Fluorine in Pharmaceutical and Medicinal Chemistry: From Biophysical Aspects to Clinical Applications, London: Imperial College Press.  Google Scholar
First citationOlszewski, T. K. & Boduszek, B. (2010). Tetrahedron, 66, 8661–8666.  Web of Science CrossRef CAS Google Scholar
First citationOxford Diffraction (2008). CrysAlis CCD. Oxford Diffraction Ltd, Abingdon, England.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals 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 citationZeng, Q., Zhang, L., Yang, J., Xu, B., Xiao, Y. & Zhang, J. (2014). Chem. Commun. 50, 4203–4206.  Web of Science CSD CrossRef CAS Google Scholar

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