Startseite Naturwissenschaften The crystal structure of 4-(trifluoromethyl)pyridine-2-carboxylic acid, C7H4F3NO2
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The crystal structure of 4-(trifluoromethyl)pyridine-2-carboxylic acid, C7H4F3NO2

  • Juan Zhou und Xinlei Zhang ORCID logo EMAIL logo
Veröffentlicht/Copyright: 23. Oktober 2025

Abstract

C7H4F3NO2, triclinic, P 1 (no. 2), a = 9.1863(6) Å, b = 15.1325(9) Å, c = 17.6356(11) Å, α = 107.189(2)°, β = 93.126(2)°, γ = 103.753(2)°, V = 2254.2(2) Å3, Z = 12, Rgt(F) = 0.0518, wRref(F2) = 0.1278, T = 100(2) K.

CCDC no.: 2477814

The molecular structure is shown in the figure. Table 1 contains the crystallographic data and the list of the atoms including atomic coordinates and displacement parameters can be found in the cif-file attached to this article.

Table 1:

Data collection and handling.

Crystal: Colourless block
Size: 0.40 × 0.28 × 0.25 mm
Wavelength: Mo Kα radiation (0.71073 Å)
μ: 0.17 mm−1
Diffractometer, scan mode: Rigaku, ω scans
θmax, completeness: 28.4°, 100 %
N(hkl)measured, N(hkl)unique, Rint: 56789, 11271, 0.054
Criterion for Iobs, N(hkl)gt: Iobs > 2 σ(Iobs), 8706
N(param)refined: 737
Programs: Rigaku, 1 Olex2, 2 SHELX 3 , 4

1 Source of materials

The title compound is commercially available and was used as received. A measured amount of the sample was dissolved in ethanol and heated very slowly to saturation. The resulting saturated solution was then left standing at room temperature for slow evaporation. Colorless block crystals were obtained after one week.

2 Experimental details

Hydrogen atoms attached to aromatic rings were located in the difference electron density map and refined using a riding model with Uiso(H) = 1.2 Ueq(C). O–H hydrogen atoms were refined with Uiso(H) = 1.5 Ueq(O). The disordered –CF3 group was refined with site occupancies of 0.775 and 0.225 over two positions. 5

3 Comment

Hydrogen bonds play critical roles in diverse chemical processes – including crystal packing, hydrogen storage materials, organometallic reaction mechanisms, and molecular recognition – proving decisive in governing material behavior under specific conditions. 6 , 7 This structural influence is clearly evidenced in carboxyl-functionalized imidazolium ionic liquids, where alkyl chain length modulation controls inter-cationic hydrogen bonding patterns to enable reversible hydrophilic-hydrophobic transitions. 8 Strong O–H⋯N/O bonds have also been found to govern crystal engineering systems, driving centrosymmetric structure formation through directional supramolecular interactions. 9 Recently, Wang et al. 10 reported a remarkable crystal structure featuring fourteen symmetry-independent molecules in its asymmetric unit (Z′ = 14). Such high-Z′ values are uncommon in crystallography and typically result from competing interactions of similar strength. Notably, the reported halogen-substituted (Cl, Br, I) pyridine-carboxylic acids consistently exhibit lower Z′ values compared to their fluorinated ones. This observation suggests a potentially unique role of fluorine in facilitating high-Z′ packing that requires more comprehensive experimental validation, a phenomenon that warrants more extensive experimental investigation. Herein, we report a second high-Z′ structure, where trifluoromethyl-substituted pyridine-2-carboxylic acid is stabilized by hydrogen bonding interactions. The title compound has also been used in coordination chemistry. 11 We present a complete structural characterization along with a detailed analysis of its intermolecular interactions.

As shown in the Figure, the crystal structure of 4-(trifluoromethyl)pyridine-2-carboxylic acid exhibits a high Z′ value of 6, indicating six crystallographically independent molecules (designated ivi) within the asymmetric unit. While adopting identical conformers, these molecules display subtle variations in structural parameters. For example, the C–O bond lengths of the carbonyl groups for molecules ivi are 1.305 (2), 1.314 (2), 1.307 (2), 1.306 (2), 1.310 (2), and 1.308 (2) Å, respectively. Although the trimers are nearly coincident upon rigid-body transformation (rotation and translation), differences in molecular geometries preclude exact superposition, resulting in the high Z′ value. Within the asymmetric unit, these six molecules assemble into two structurally similar trimeric groups (iiiiii and ivvvi), each forming a coplanar assembly. In each trimer, three almost linear O–H⋯N hydrogen bonds between carboxylic acid groups and pyridyl nitrogen atoms generate an R33(15) ring motif. Distinct hydrogen-bond geometries exist between the two trimers, as illustrated in the Figure. In trimer iiiiii, molecule i links to ii via O11–H11⋯N1 [d(O⋯N) = 2.712 (2) Å, θ = 175°] interaction, ii connects to iii via O6–H6⋯N6 [d(O⋯N) = 2.711 (2) Å, θ = 171°] interaction, and iii bonds to i via O4–H4⋯N3 [d(O⋯N) = 2.720 (2) Å, θ = 171°] interaction. In trimer ivvvi, iv associates with v via O8–H8⋯N5 [d(O⋯N) = 2.705 (2) Å, θ = 171°] interaction, v bonds to vi via O10–H10⋯N2 [d(O⋯N) = 2.711 (2) Å, θ = 177°] interaction, and vi links to iv via O7–H7⋯N6 [d(O⋯N) = 2.733 (2) Å, θ = 166°] interaction, thereby forming two analogous cyclic O–H⋯N hydrogen-bonded networks. Additionally, hydroxyl groups within each trimer further stabilize the assembly through cyclic O–H⋯O hydrogen bonds, forming an R33(6) motif with an averaging d(O⋯O) distance of 3.29 Å. Adjacent trimers associate via weak C–H⋯O with O⋯O distances averaging 3.20 Å and C–H⋯F interactions with C⋯O distances averaging 3.50 Å interactions. These layers further consolidate into a three-dimensional architecture through additional very weak C–H⋯O [d(C⋯O) = 3.20–3.32 Å] and C–H⋯F [d(C⋯F) = 3.30–3.31 Å] hydrogen bonds.

Quantum chemical calculations at the B3LYP–D3(BJ)/6–311+G** level were employed to optimize geometries of three dimeric configurations and a trimeric structure extracted directly from the crystal structure. H-bonding energy computations for O–H⋯O, O–H⋯N, O–H⋯F, and C–H⋯O interactions revealed distinct aggregation-dependent trends. In dimers, O–H⋯O emerged as the strongest hydrogen bond (∼10.2 kcal/mol), followed by O–H⋯N (∼8.3 kcal/mol), while O–H⋯F (∼2.8 kcal/mol) and C–H⋯O (∼2.6 kcal/mol) exhibited comparable energies characteristic of very weak hydrogen bonding. Remarkably, trimerization dramatically altered this hierarchy. O–H⋯N binding energy increased significantly to ∼10.7 kcal/mol and become the dominant interaction, whereas O–H⋯O and C–H⋯O energies decreased markedly to ∼1.9 and ∼0.9 kcal/mol, respectively. These significant energy shifts demonstrate that how molecules assemble in crystals directly controls hydrogen bond strengths and reorganizes intermolecular force networks, thereby potentially influencing crystal packing arrangements.


Corresponding author: Xinlei Zhang, School of Chemistry and Chemical Engineering, Henan Key Laboratory of Rare Earth Functional Materials, Zhoukou Normal University, Zhoukou 466001, P.R. China, E-mail:

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

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

  3. Research funding: This research was funded by the high-level talent research launch project of Zhoukou Normal University (project number: ZKNUC2024023, ZKNUC2023073).

References

1. Rigaku, O. D. CrysAlisPRO; Rigaku Oxford Diffraction Ltd: Yarnton, Oxfordshire, England, 2017.Suche in Google Scholar

2. Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.; Puschmann, H. Olex2: A Complete Structure Solution, Refinement and Analysis Program. J. Appl. Crystallogr. 2009, 42, 339–341; https://doi.org/10.1107/s0021889808042726.Suche in Google Scholar

3. Sheldrick, G. Crystal Structure Refinement with Shelxl. Acta Crystallogr. 2015, C71, 3–8; https://doi.org/10.1107/s2053229614024218.Suche in Google Scholar

4. Sheldrick, G. M. Shelxt. Integrated Space-Group and Crystal Structure Determination. Acta Crystallogr. 2015, A71, 3–8.10.1107/S2053273314026370Suche in Google Scholar PubMed PubMed Central

5. Zhang, J.; Ma, X.-F.; Xuan, X.-P. Disordered Fragments of Chemical Structures Based on Single-Crystal X-Ray Diffraction. Chin. J. Struct. Chem. 2020, 39, 698–708.Suche in Google Scholar

6. Perrin, C. L.; Nielson, J. B. “Strong” Hydrogen Bonds in Chemistry and Biology. Annu. Rev. Phys. Chem. 1997, 48, 511–544; https://doi.org/10.1146/annurev.physchem.48.1.511.Suche in Google Scholar PubMed

7. Belkova, N. V.; Epstein, L. M.; Filippov, O. A.; Shubina, E. S. Hydrogen and Dihydrogen Bonds in the Reactions of Metal Hydrides. Chem. Rev. 2016, 116, 8545–8587; https://doi.org/10.1021/acs.chemrev.6b00091.Suche in Google Scholar PubMed

8. Li, Z.; Li, A.; Zhou, Y.; Zhang, L.; Zhao, Y.; Xuan, X. From Hydrophobity to Hydrophilicity: Design, Synthesis, Structural Transformation and Distinguishment of Highly Symmetric 1,3-Bis(Carboxymethyl)Imidazolium Bis(Trifluoromethyl)Sulfonyl)Amide Ionic Liquids. J. Mol. Struct. 2021, 1231, 129688; https://doi.org/10.1016/j.molstruc.2020.129688.Suche in Google Scholar

9. Waddell, P. G. A Lot to Unpack: A Decade in High Z′ Crystal Structures. CrystEngComm 2025, 27, 578–589; https://doi.org/10.1039/d4ce01186d.Suche in Google Scholar

10. Xue, X.-D.; Wang, S.-C.; Li, M.-Y.; Wang, Z. Ultralong Room-Temperature Phosphorescence in Ca(II) Metal-Organic Frameworks Based on Nicotinic Acid Ligands. Inorg. Chem. 2024, 63, 21336–21344; https://doi.org/10.1021/acs.inorgchem.4c03868.Suche in Google Scholar PubMed

11. Pan, X.; Kong, X.-Y. Crystal structure of 3-chloro-5-(trifluoromethyl)pyridine-2-carboxylic acid, C7H3ClF3NO2. Z. Kristallogr. N. Cryst. Struct. 2025, 240, 135–137 https://doi.org/10.1515/ncrs-2024-0401.Suche in Google Scholar

Received: 2025-08-13
Accepted: 2025-10-05
Published Online: 2025-10-23
Published in Print: 2025-12-17

© 2025 the author(s), published by De Gruyter, Berlin/Boston

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

Artikel in diesem Heft

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