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

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ISSN: 2056-9890

Tri­phenyl­methyl benzoate

aDepartment of Chemistry, University of South Alabama, Mobile, AL 36688-0002, USA, and bDepartment of Chemistry, Seattle Pacific University, Seattle, WA 98119-1997, USA
*Correspondence e-mail: spyrig@spu.edu

(Received 8 July 2009; accepted 21 July 2009; online 29 July 2009)

The title compound, C26H20O2, has long been known, but was not structurally characterized until now. It adopts the Z conformation and the atoms comprising the ester linkage are essentially coplanar (r.m.s. deviation of 0.0234 Å). The acyl C—O bond length of 1.470 (2) Å falls within the normal range seen for esters of tertiary alcohols and is below the value of 1.496 Å found in tri-tert-butyl­methyl 4-nitro­benzoate.

Related literature

For related structures of sterically hindered esters, see: phenyl benzoate (Adams & Morsi, 1976[Adams, J. M. & Morsi, S. E. (1976). Acta Cryst. B32, 1345-1347.]), a 4-substituted tert-butyl benzoate (Fu et al., 2008[Fu, N., Zou, X.-M., Lin, D.-Y., Zhu, Y.-Q. & Yang, H.-Z. (2008). Acta Cryst. E64, o192.]), tri-tert-butyl­methyl 4-nitro­benzoate (Cheng & Nyburg, 1978[Cheng, P.-T. & Nyburg, S. C. (1978). Acta Cryst. B34, 3001-3004.]), and for esters of tertiary alcohols, see: Allen & Kirby (1984[Allen, F. H. & Kirby, A. J. (1984). J. Am. Chem. Soc. 106, 6197-6200.]); Schweizer & Dunitz (1982[Schweizer, W. B. & Dunitz, J. D. (1982). Helv. Chem. Acta, 65, 1547-1554.]). For the synthesis, see: Blicke (1923[Blicke, F. F. (1923). J. Am. Chem. Soc. 45, 1965-1969.]) and for ionic field studies in solutions of the title compound, see: Velazquez et al. (2006[Velazquez, H. A., Hollingsworth, J., Spyridis, G. T. & Pocker, Y. (2006). 231st American Chemical Society National Meeting, Chemical Education Abstract No. 403.]). For additional related references on the calculated absolute structure parameter and the conformations of esters, see: (Flack, 1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]) and Pawar et al. (1998[Pawar, P. M., Khalil, A. A., Hooks, D. R., Collins, K., Elliott, T., Stafford, J., Smith, L. & Noe, E. A. (1998). J. Am. Chem. Soc. 120, 2108-2112.]).

[Scheme 1]

Experimental

Crystal data
  • C26H20O2

  • Mr = 364.42

  • Orthorhombic, P n a 21

  • a = 8.9512 (4) Å

  • b = 14.9545 (5) Å

  • c = 14.4038 (6) Å

  • V = 1928.10 (13) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 290 K

  • 0.50 × 0.15 × 0.07 mm

Data collection
  • Oxford Diffraction Xcalibur diffractometer with an Eos CCD detector

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.959, Tmax = 0.995

  • 6656 measured reflections

  • 2664 independent reflections

  • 1879 reflections with I > 2σ(I)

  • Rint = 0.022

Refinement
  • R[F2 > 2σ(F2)] = 0.036

  • wR(F2) = 0.070

  • S = 0.91

  • 2664 reflections

  • 254 parameters

  • 1 restraint

  • H-atom parameters constrained

  • Δρmax = 0.12 e Å−3

  • Δρmin = −0.12 e Å−3

Data collection: CrysAlis Pro (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis Pro. Oxford Diffraction Ltd, Yarnton, England.]); cell refinement: CrysAlis Pro; data reduction: CrysAlis Pro; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: publCIF (Westrip, 2009[Westrip, S. P. (2009). publCIF. In preparation.]).

Supporting information


Comment top

In light of our investigations into the use of the title compound as a probe of the ionic fields present in LiClO4-Et2O solutions, (Velazquez et al., 2006), we prepared and crystallized triphenylmethyl benzoate, (I). The title compound adopts the Z-conformation (Pawar et al. 1998) with the C2—C1—O1—C8 dihedral angle being 3.5 (1)° and the phenyl ring exhibiting a slight twist of 17.6 (2)° with respect to the ester group. The atoms comprising the ester linkage, C2, C1, O2, O1 and C8, are essentially coplanar. The acyl C—O bond length of 1.470 (2) Å falls within the normal range as seen for the esters of tertiary alcohols (Allen & Kirby, 1984; Schweizer & Dunitz, 1982) and is well below the value of 1.496 Å in tri-tert-butylmethyl 4-nitrobenzoate (Cheng & Nyburg, 1978). The C1—O1—C8 bond angle is 120.50 (13)°, midway between the 118.3° observed in phenyl benzoate (Adams & Morsi, 1976) and the 122.9° seen in a 4-substituted tert-butyl benzoate (Fu et al. 2008), and is consistent with those noted for the esters of tertiary alcohols (Schweizer & Dunitz, 1982).

Related literature top

For related structures of sterically hindered esters, see: phenyl benzoate (Adams & Morsi, 1976), 4-substituted tert-butyl benzoate (Fu et al. (2008)), tri-tert-butylmethyl 4-nitrobenzoate (Cheng & Nyburg, 1978), and for esters of tertiary alcohols, see: Allen & Kirby (1984); Schweizer & Dunitz (1982). Related literature also includes the synthesis (Blicke, 1923) and ionic field studies in solutions of the title compound (Velazquez et al., 2006). For additional related references, see: (Flack, 1983) and Pawar et al. (1998).

Experimental top

The title compound was synthesized by reacting trityl chloride with silver benzoate in dry benzene as outlined in the literature (Blicke, 1923). Crystals were grown by slow evaporation from benzene at 298 K. m.p. 442.5–444.15 K.

Refinement top

H-atoms were placed in calculated positions and allowed to ride during subsequent refinement, with Uiso(H) = 1.2Ueq(C) and C—H distances of 0.93 Å for all H atoms. The calculated absolute structure parameter (Flack, 1983) and e.s.d. was meaningless with a value of 0.1 (12). For this reason, the Friedel-pair reflections were merged before the final refinement.

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXP97 (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), with the atom-numbering scheme. Displacement ellipsoids for non-hydrogen atoms are drawn at the 50% probability level.
Triphenylmethyl benzoate top
Crystal data top
C26H20O2Dx = 1.255 Mg m3
Mr = 364.42Melting point = 440.5–444.5 K
Orthorhombic, Pna21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2nCell parameters from 2913 reflections
a = 8.9512 (4) Åθ = 3.1–30.4°
b = 14.9545 (5) ŵ = 0.08 mm1
c = 14.4038 (6) ÅT = 290 K
V = 1928.10 (13) Å3Prism, colorless
Z = 40.50 × 0.15 × 0.07 mm
F(000) = 768
Data collection top
Oxford Diffraction Xcalibur
diffractometer with an Eos CCD detector
2664 independent reflections
Radiation source: fine-focus sealed tube1879 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
Detector resolution: 16.0514 pixels mm-1θmax = 30.4°, θmin = 3.6°
ω scansh = 116
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
k = 208
Tmin = 0.959, Tmax = 0.995l = 1420
6656 measured reflections
Refinement top
Refinement on F2Secondary atom site location: none
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.036H-atom parameters constrained
wR(F2) = 0.070 w = 1/[σ2(Fo2) + (0.0394P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.91(Δ/σ)max < 0.001
2664 reflectionsΔρmax = 0.12 e Å3
254 parametersΔρmin = 0.12 e Å3
1 restraintExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0067 (13)
Crystal data top
C26H20O2V = 1928.10 (13) Å3
Mr = 364.42Z = 4
Orthorhombic, Pna21Mo Kα radiation
a = 8.9512 (4) ŵ = 0.08 mm1
b = 14.9545 (5) ÅT = 290 K
c = 14.4038 (6) Å0.50 × 0.15 × 0.07 mm
Data collection top
Oxford Diffraction Xcalibur
diffractometer with an Eos CCD detector
2664 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1879 reflections with I > 2σ(I)
Tmin = 0.959, Tmax = 0.995Rint = 0.022
6656 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0361 restraint
wR(F2) = 0.070H-atom parameters constrained
S = 0.91Δρmax = 0.12 e Å3
2664 reflectionsΔρmin = 0.12 e Å3
254 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.

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 > 2σ(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
xyzUiso*/Ueq
O10.09567 (13)0.02387 (8)0.19684 (8)0.0377 (3)
O20.27149 (15)0.04826 (9)0.28069 (10)0.0513 (3)
C10.23123 (18)0.01384 (11)0.20970 (13)0.0364 (4)
C20.3253 (2)0.00547 (11)0.12520 (13)0.0389 (4)
C30.2950 (2)0.05570 (13)0.05580 (13)0.0470 (5)
H30.21090.09200.06020.056*
C40.3891 (3)0.06332 (16)0.02053 (15)0.0611 (6)
H40.36840.10450.06710.073*
C50.5127 (3)0.0096 (2)0.02643 (17)0.0715 (7)
H50.57640.01460.07720.086*
C60.5431 (3)0.05147 (18)0.0419 (2)0.0729 (7)
H60.62670.08810.03670.087*
C70.4512 (2)0.05927 (14)0.11823 (16)0.0564 (5)
H70.47340.10030.16480.068*
C80.01225 (19)0.02868 (11)0.27363 (12)0.0340 (4)
C90.05440 (19)0.06734 (11)0.30194 (12)0.0352 (4)
C100.1514 (2)0.11564 (12)0.24597 (14)0.0486 (5)
H100.19270.08880.19370.058*
C110.1874 (3)0.20348 (13)0.26723 (17)0.0612 (6)
H110.25180.23530.22880.073*
C120.1287 (3)0.24365 (13)0.34465 (17)0.0589 (6)
H120.15380.30240.35910.071*
C130.0327 (2)0.19667 (12)0.40057 (16)0.0517 (5)
H130.00730.22390.45300.062*
C140.0052 (2)0.10936 (12)0.37983 (14)0.0424 (4)
H140.07090.07840.41820.051*
C150.0481 (2)0.08856 (11)0.35106 (13)0.0361 (4)
C160.1604 (2)0.15027 (12)0.33333 (15)0.0480 (5)
H160.20580.15170.27530.058*
C170.2052 (3)0.20958 (14)0.40161 (19)0.0649 (7)
H170.28190.24990.38940.078*
C180.1379 (3)0.20969 (14)0.48721 (18)0.0672 (7)
H180.16810.25010.53260.081*
C190.0260 (3)0.14994 (15)0.50529 (16)0.0622 (6)
H190.02030.15000.56310.075*
C200.0189 (2)0.08948 (13)0.43834 (13)0.0481 (5)
H200.09470.04890.45170.058*
C210.14691 (19)0.07741 (10)0.23019 (12)0.0364 (4)
C220.1388 (2)0.12181 (13)0.14637 (15)0.0545 (5)
H220.05050.12050.11240.065*
C230.2611 (3)0.16830 (15)0.11242 (19)0.0677 (7)
H230.25390.19810.05590.081*
C240.3917 (2)0.17089 (13)0.1609 (2)0.0619 (6)
H240.47330.20220.13770.074*
C250.4017 (2)0.12700 (15)0.24394 (18)0.0601 (6)
H250.49050.12840.27740.072*
C260.2805 (2)0.08062 (13)0.27826 (16)0.0512 (5)
H260.28890.05100.33480.061*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0315 (6)0.0499 (6)0.0316 (6)0.0018 (5)0.0016 (5)0.0073 (6)
O20.0433 (7)0.0647 (8)0.0459 (8)0.0086 (6)0.0012 (7)0.0170 (7)
C10.0318 (9)0.0397 (8)0.0377 (10)0.0005 (7)0.0008 (8)0.0045 (8)
C20.0331 (9)0.0452 (9)0.0385 (10)0.0048 (8)0.0011 (8)0.0075 (9)
C30.0390 (11)0.0613 (12)0.0407 (11)0.0085 (9)0.0003 (8)0.0032 (10)
C40.0582 (15)0.0878 (15)0.0373 (11)0.0193 (12)0.0025 (11)0.0017 (12)
C50.0568 (15)0.109 (2)0.0482 (13)0.0211 (14)0.0167 (12)0.0187 (15)
C60.0523 (15)0.0930 (18)0.0732 (17)0.0105 (13)0.0152 (13)0.0237 (15)
C70.0464 (12)0.0656 (12)0.0572 (13)0.0076 (10)0.0028 (11)0.0081 (11)
C80.0313 (9)0.0397 (9)0.0310 (9)0.0004 (7)0.0020 (7)0.0017 (8)
C90.0339 (9)0.0363 (8)0.0352 (10)0.0007 (7)0.0051 (8)0.0005 (8)
C100.0560 (12)0.0483 (10)0.0414 (11)0.0051 (10)0.0024 (9)0.0026 (9)
C110.0712 (15)0.0511 (12)0.0611 (15)0.0175 (10)0.0012 (12)0.0137 (12)
C120.0751 (15)0.0384 (10)0.0633 (13)0.0080 (10)0.0131 (12)0.0023 (11)
C130.0594 (13)0.0429 (10)0.0529 (13)0.0007 (9)0.0052 (10)0.0099 (10)
C140.0442 (11)0.0415 (9)0.0416 (10)0.0015 (8)0.0012 (8)0.0026 (9)
C150.0369 (10)0.0333 (8)0.0380 (10)0.0033 (7)0.0080 (8)0.0034 (8)
C160.0545 (12)0.0409 (9)0.0488 (12)0.0062 (8)0.0097 (10)0.0058 (9)
C170.0739 (16)0.0410 (10)0.0798 (18)0.0098 (10)0.0277 (14)0.0023 (12)
C180.0845 (18)0.0490 (11)0.0682 (17)0.0092 (12)0.0348 (14)0.0176 (12)
C190.0716 (16)0.0685 (15)0.0465 (12)0.0149 (13)0.0105 (11)0.0109 (12)
C200.0520 (12)0.0501 (11)0.0421 (11)0.0020 (9)0.0028 (9)0.0037 (10)
C210.0317 (9)0.0365 (8)0.0410 (11)0.0018 (7)0.0039 (8)0.0017 (8)
C220.0417 (11)0.0644 (11)0.0574 (13)0.0009 (10)0.0059 (10)0.0180 (12)
C230.0558 (14)0.0701 (13)0.0771 (17)0.0055 (11)0.0182 (13)0.0245 (13)
C240.0489 (13)0.0501 (11)0.0866 (18)0.0090 (9)0.0288 (13)0.0054 (13)
C250.0361 (11)0.0703 (13)0.0739 (16)0.0085 (10)0.0039 (11)0.0200 (13)
C260.0400 (10)0.0628 (12)0.0508 (12)0.0055 (9)0.0001 (10)0.0017 (11)
Geometric parameters (Å, º) top
O1—C11.351 (2)C13—C141.382 (3)
O1—C81.470 (2)C13—H130.9300
O2—C11.200 (2)C14—H140.9300
C1—C21.486 (2)C15—C161.389 (3)
C2—C31.382 (3)C15—C201.393 (3)
C2—C71.388 (3)C16—C171.384 (3)
C3—C41.390 (3)C16—H160.9300
C3—H30.9300C17—C181.373 (4)
C4—C51.370 (4)C17—H170.9300
C4—H40.9300C18—C191.367 (3)
C5—C61.369 (4)C18—H180.9300
C5—H50.9300C19—C201.382 (3)
C6—C71.378 (3)C19—H190.9300
C6—H60.9300C20—H200.9300
C7—H70.9300C21—C221.380 (3)
C8—C151.529 (2)C21—C261.383 (3)
C8—C91.540 (2)C22—C231.386 (3)
C8—C211.541 (2)C22—H220.9300
C9—C101.388 (3)C23—C241.362 (3)
C9—C141.392 (3)C23—H230.9300
C10—C111.387 (3)C24—C251.368 (3)
C10—H100.9300C24—H240.9300
C11—C121.372 (3)C25—C261.379 (3)
C11—H110.9300C25—H250.9300
C12—C131.371 (3)C26—H260.9300
C12—H120.9300
C1—O1—C8120.50 (13)C12—C13—H13119.6
O2—C1—O1124.44 (16)C14—C13—H13119.6
O2—C1—C2124.32 (15)C13—C14—C9120.44 (19)
O1—C1—C2111.22 (15)C13—C14—H14119.8
C3—C2—C7119.40 (19)C9—C14—H14119.8
C3—C2—C1122.47 (17)C16—C15—C20118.12 (17)
C7—C2—C1118.09 (18)C16—C15—C8120.72 (17)
C2—C3—C4120.5 (2)C20—C15—C8120.79 (16)
C2—C3—H3119.8C17—C16—C15120.3 (2)
C4—C3—H3119.8C17—C16—H16119.8
C5—C4—C3119.4 (2)C15—C16—H16119.8
C5—C4—H4120.3C18—C17—C16120.8 (2)
C3—C4—H4120.3C18—C17—H17119.6
C6—C5—C4120.4 (2)C16—C17—H17119.6
C6—C5—H5119.8C19—C18—C17119.5 (2)
C4—C5—H5119.8C19—C18—H18120.3
C5—C6—C7120.8 (2)C17—C18—H18120.3
C5—C6—H6119.6C18—C19—C20120.5 (2)
C7—C6—H6119.6C18—C19—H19119.7
C6—C7—C2119.5 (2)C20—C19—H19119.7
C6—C7—H7120.2C19—C20—C15120.7 (2)
C2—C7—H7120.2C19—C20—H20119.6
O1—C8—C15110.20 (13)C15—C20—H20119.6
O1—C8—C9108.33 (13)C22—C21—C26117.85 (18)
C15—C8—C9116.08 (14)C22—C21—C8122.77 (16)
O1—C8—C21103.39 (13)C26—C21—C8119.32 (16)
C15—C8—C21107.19 (12)C21—C22—C23120.5 (2)
C9—C8—C21110.90 (13)C21—C22—H22119.7
C10—C9—C14118.24 (16)C23—C22—H22119.7
C10—C9—C8119.00 (15)C24—C23—C22120.8 (2)
C14—C9—C8122.71 (16)C24—C23—H23119.6
C11—C10—C9120.7 (2)C22—C23—H23119.6
C11—C10—H10119.7C23—C24—C25119.4 (2)
C9—C10—H10119.7C23—C24—H24120.3
C12—C11—C10120.3 (2)C25—C24—H24120.3
C12—C11—H11119.8C24—C25—C26120.2 (2)
C10—C11—H11119.8C24—C25—H25119.9
C13—C12—C11119.56 (18)C26—C25—H25119.9
C13—C12—H12120.2C25—C26—C21121.2 (2)
C11—C12—H12120.2C25—C26—H26119.4
C12—C13—C14120.7 (2)C21—C26—H26119.4

Experimental details

Crystal data
Chemical formulaC26H20O2
Mr364.42
Crystal system, space groupOrthorhombic, Pna21
Temperature (K)290
a, b, c (Å)8.9512 (4), 14.9545 (5), 14.4038 (6)
V3)1928.10 (13)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.50 × 0.15 × 0.07
Data collection
DiffractometerOxford Diffraction Xcalibur
diffractometer with an Eos CCD detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.959, 0.995
No. of measured, independent and
observed [I > 2σ(I)] reflections
6656, 2664, 1879
Rint0.022
(sin θ/λ)max1)0.713
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.036, 0.070, 0.91
No. of reflections2664
No. of parameters254
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.12, 0.12

Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXP97 (Sheldrick, 2008), publCIF (Westrip, 2009).

 

Acknowledgements

The authors gratefully acknowledge the National Science Foundation for their generous support (NSF-CAREER grant to RES, CHE-0846680).

References

First citationAdams, J. M. & Morsi, S. E. (1976). Acta Cryst. B32, 1345-1347.  CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationAllen, F. H. & Kirby, A. J. (1984). J. Am. Chem. Soc. 106, 6197–6200.  CrossRef CAS Web of Science Google Scholar
First citationBlicke, F. F. (1923). J. Am. Chem. Soc. 45, 1965–1969.  CrossRef CAS Google Scholar
First citationCheng, P.-T. & Nyburg, S. C. (1978). Acta Cryst. B34, 3001–3004.  CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationFu, N., Zou, X.-M., Lin, D.-Y., Zhu, Y.-Q. & Yang, H.-Z. (2008). Acta Cryst. E64, o192.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationOxford Diffraction (2009). CrysAlis Pro. Oxford Diffraction Ltd, Yarnton, England.  Google Scholar
First citationPawar, P. M., Khalil, A. A., Hooks, D. R., Collins, K., Elliott, T., Stafford, J., Smith, L. & Noe, E. A. (1998). J. Am. Chem. Soc. 120, 2108–2112.  Web of Science CrossRef CAS Google Scholar
First citationSchweizer, W. B. & Dunitz, J. D. (1982). Helv. Chem. Acta, 65, 1547–1554.  CrossRef CAS Web of Science Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationVelazquez, H. A., Hollingsworth, J., Spyridis, G. T. & Pocker, Y. (2006). 231st American Chemical Society National Meeting, Chemical Education Abstract No. 403.  Google Scholar
First citationWestrip, S. P. (2009). publCIF. In preparation.  Google Scholar

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