Crystal Structure, Hirshfeld Surface Analysis, and Computational Study of (E)-2-Phenyl-N’-(1,7,7-Trimethylbicyclo[2.2.1]Heptan-2-Ylidene)Acetohydrazide

ABSTRACT

The crystal structure of camphor derived Schiff base (E)-2-phenyl-N‘-(1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)acetohydrazide (C₁₈H₂₄N₂O), was determined by single-crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Pna2₁, with unit cell parameters a = 8.2157(5) Å, b = 15.6570(13) Å, c = 12.5573(10) Å, and Z = 4. The molecule adopts an E-configuration across the imine bond, and the rigid bicyclic camphor scaffold enforces structural stability. Hirshfeld surface analysis revealed dominant H···H and C···H/H···C interactions, supported by 2D fingerprint plots. The energy framework and interaction energy calculations using B3LYP/6-31G(d,p) level theory confirmed dispersion as the principal stabilizing force in the crystal packing, with the strongest intermolecular interaction recorded at −72.4 kJ/mol. The structure was refined to R₁ = 0.0582 and wR₂ = 0.1454 for [I > 2σ(I)], with an absolute structure parameter of −0.4(5). These findings provide insights into the supramolecular architecture of camphor-based Schiff bases and underscore their potential applications in medicinal chemistry.

References

• [1] K. Vara, M. B. Parmar, M. Modak, J. H. Pandya. Substituted Camphor-Hydrazide Schiff Bases: Synthesis, Characterization, and Anticancer Activity. World Scientific News 2025;206:17-29.
• [2] R. Spackman, M. J. Turner, J. J. McKinnon, S. K. Wolff, D. J. Grimwood, D. Jayatilaka, M. A. Spackman. CrystalExplorer: a program for Hirshfeld surface analysis, visualization and qu­antitative analysis of molecular crystals. J. Appl. Cryst. 2021;54(3):1006-11. https://doi.org/10.1107/S1600576721002910
• [3] A. Spackman, J. J. McKinnon, Fingerprinting Intermolecular Interactions in Molecular Crystals. CrystEngComm. 2002;4(66):378-92. https://doi.org/10.1039/B203191B
• [4] J. McKinnon, D. Jayatilaka, M. A. Spackman, Towards quantitative analysis of intermolecular interactions with Hirshfeld surfaces. Chem Commun. 2007;(37):3814-6. https://doi.org/10.1039/B704980C
• [5] APEX2 and SAINT. Bruker AXS Inc. 2004 Madison, Wisconsin, USA.
• [6] Altornare, G. Cascarano, C. Giacovazzo, A. J. Guagliardi. SIR92, Appl. Cryst. 1993;26:343-50. https://doi.org/10.1107/S0021889892010331
• [7] M. Sheldrick. short history of SHELX. Acta Cryst. 2008;A64:112-22. https://doi.org/10.1107/S0108767307043930
• [8] J. Farrugia. WinGX and ORTEP for Windows: an update. J. Appl. Cryst. 2012;45:849-54. https://doi.org/10.1107/S0021889812029111
• [9] Bruno, J. C. Cole, P. R. Edgington, M. Kessler, C. F. Macrae, P. McCabe, J. Pearson, R. Taylor. New software for searching the Cambridge Structural Database and visualizing crystal structures. Acta Cryst. (2002). B58, 389-97. https://doi.org/10.1107/S0108768102003324

Download all article in PDF

WSN 208 (2025) 106-125

ADVERTISEMENT