Home The crystal structure of 2,6-difluorophenol, C6H4F2O
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The crystal structure of 2,6-difluorophenol, C6H4F2O

  • Pholani Manana , Jarryd Cuthbertson , Eric C. Hosten ORCID logo and Richard Betz ORCID logo EMAIL logo
Published/Copyright: October 2, 2020

Abstract

C6H4F2O, orthorhombic, P212121 (no. 19), a = 4.9287(5) Å, b = 10.1752(8) Å, c = 10.9156(10) Å, V = 547.42(9) Å3, Z = 4, Rgt(F) = 0.0248, wRref(F2) = 0.0705, T = 200 K.CCDC no.: 2025946

The molecular structure is shown in the figure. Table 1 contains crystallographic data and Table 2 contains the list of the atoms including atomic coordinates and displacement parameters.

Table 1:

Data collection and handling.

Crystal:Colourless block
Size:0.54 × 0.52 × 0.48 mm
Wavelength:Mo Kα radiation (0.71073 Å)
μ:0.15 mm−1
Diffractometer, scan mode: Θmax, completeness:Bruker APEX-II, φ and ω 28.4°, >99%
N(hkl)measured, N(hkl)unique, Rint:5425, 1357, 0.014
Criterion for Iobs, N(hkl)gt:Iobs > 2 σ(Iobs), 1290
N(param)refined:98
Programs:Bruker [1], [6], SHELX [2], WinGX/ORTEP [3], Mercury [4], PLATON [5]
Table 2:

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2).

AtomxyzUiso*/Ueq
F10.2083 (2)0.49910 (11)0.54795 (10)0.0461 (3)
F20.9445 (2)0.63057 (11)0.30789 (10)0.0438 (3)
O10.5649 (2)0.68580 (11)0.48661 (11)0.0350 (3)
H10.711 (6)0.723 (3)0.484 (2)0.059 (7)*
C10.5775 (3)0.56673 (14)0.42963 (12)0.0263 (3)
C20.3940 (3)0.46969 (15)0.46046 (13)0.0306 (3)
C30.3923 (4)0.34802 (15)0.40540 (16)0.0371 (4)
H30.267 (5)0.286 (2)0.428 (2)0.051 (6)*
C40.5833 (4)0.32147 (16)0.31579 (16)0.0389 (4)
H40.591 (5)0.235 (2)0.271 (2)0.052 (6)*
C50.7712 (4)0.41559 (16)0.28131 (14)0.0355 (3)
H50.901 (5)0.401 (2)0.223 (2)0.049 (6)*
C60.7636 (3)0.53635 (13)0.33867 (13)0.0291 (3)

Source of material

The compound was obtained commercially (fluorochem). Crystals suitable for the diffraction studies were obtained by repeated melting and freezing of the compound in a fridge around 0 °C.

Experimental details

All H atoms were located on a difference map and refined freely.

Comment

Phenol and derivatives are interesting bonding partners for a variety of transition metals and elements from the p-block. They can act as neutral or – upon deprotonation – as anionic ligands. Upon variation of the substituents on the aromatic system, a seemingly endless series of symmetric as well as asymmetric phenol derivatives featuring different steric pretenses and acidities of the hydroxyl-group are available. For phenol and phenolate, all bonding modes from monodentate (e.g. towards beryllium [7]) via bidentate (e.g. towards tin [8]) and tridentate (e.g. towards zinc [9], [10]) to tetradentate (e.g. towards sodium [11]) have been observed and secured on grounds of structural studies. Elucidating the coordination behaviour of various phenol in dependence of pH-value and substitution pattern it seemed of interest to determine the crystal structure of the title compound to enable comparisons with metric parameters in envisioned coordination compounds. Recently, the molecular and crystal structures of 2-hydroxy-5-methylisophthalaldehyde [12], 3,5-dimethylphenol [13], 2,3,4,5,6-pentabromophenol [14] and 4-ethylphenol [15] have been determined. The structures of 2,6-dichlorophenol [16] and 2,6-diiodophenol in a co-crystal [17] are apparent in the literature next to the structure of the title compound co-crystallized with a 4-alkoxystilbazole [18].

The title compound is the difluorinated derivative of phenol bearing the two fluoro substituents in the two ortho positions to the hydroxyl group. The two C–F bond lengths vary slightly with values of 1.3514(17) Å and 1.3634(16) Å. Both values are in good agreement with compounds featuring fluorinated phenyl groups whose metrical parameters have been deposited with the Cambridge Structural Database [19]. C–C–C angles cover a range of 116.65(12)–122.75(14)° and 122.78(14)° with the smallest angle found on the carbon atom bearing the hydroxyl group and the largest two values invariably found on the carbon atoms bonded to the fluorine atoms.

In the crystal structure, the molecules are connected by means of cooperative hydrogen bonds. In terms of graph-set analysis [20], the descriptor for these hydrogen bonds – on the unary level – is C11(2). The molecules are connected to infinite chains along the crystallographic a axis. π stacking is not a prominent feature in the title structure with the shortest distance between two centers of gravity of 4.9287(11) Å being in line with the length of the a axis of the unit cell.


Corresponding author: Richard Betz, Department of Chemistry, Nelson Mandela University Summerstrand, Campus (South), UniversityWay, Summerstrand, PO Box 77000, Port Elizabeth, 6031, South Africa, E-mail:

Funding source: National Research Foundation

Acknowledgments

The corresponding author thanks the National Research Foundation for financial support.

  1. Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: None declared.

  3. Conflict of interest statement: The authors declare no conflicts of interest regarding this article.

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Received: 2020-08-03
Accepted: 2020-09-28
Published Online: 2020-10-02
Published in Print: 2021-01-26

© 2020 Pholani Manana et al., published by De Gruyter, Berlin/Boston

This work is licensed under the Creative Commons Attribution 4.0 International License.

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