(E)-1-Phenyl-ethanone semicarbazone.

Area of Science:

• Crystallography
• Solid-state chemistry
• Molecular structure analysis

Background:

• Crystal structure determination is crucial for understanding material properties.
• Disorder in crystal structures can complicate analysis and affect physical characteristics.
• Semicarbazone derivatives are known for diverse biological activities and coordination chemistry.

Purpose of the Study:

• To elucidate the crystal structure of the title compound C(9)H(11)N(3)O.
• To investigate the implications of benzene ring disorder on space group determination.
• To analyze the molecular geometry and intermolecular interactions within the crystal lattice.

Main Methods:

• Single-crystal X-ray diffraction was employed for structural analysis.
• Crystallographic software (PLATON) was used for structure solution and refinement.
• Analysis of bond lengths, bond angles, dihedral angles, and intermolecular interactions (hydrogen bonds, C-H···π) was performed.

Main Results:

• The benzene ring in C(9)H(11)N(3)O exhibits positional disorder with occupancies of 0.922(5) and 0.078(5).
• The initially recommended space group C2/m was found to be inconsistent with the observed reflections, suggesting an alternative, likely P2(1)/c, despite higher R values.
• The semicarbazone group is planar, forming dihedral angles of 33.61(8)° and 39.1(9)° with the major and minor benzene ring components, respectively.
• Intermolecular N-H⋯O hydrogen bonds link molecules into chains along the c-axis, further stabilized by weak C-H⋯π interactions.

Conclusions:

• The crystal structure of C(9)H(11)N(3)O is characterized by benzene ring disorder and specific intermolecular interactions.
• The findings highlight the importance of careful crystallographic analysis to correctly identify space groups, especially in cases of disorder.
• The identified hydrogen bonding network and π-interactions provide insights into the packing and stability of the crystal structure.