(E)-16-(4-Chloro-benzyl-idene)estrone.

Area of Science:

• Organic Chemistry
• Crystallography
• Molecular Structure Analysis

Background:

• Understanding the three-dimensional structure of organic molecules is crucial for predicting their properties and reactivity.
• Chlorinated organic compounds often exhibit unique structural features due to the presence of the chlorine atom.

Purpose of the Study:

• To elucidate the detailed molecular structure of the title compound, C25H25ClO2.
• To analyze the conformational preferences of the different rings within the molecule.
• To investigate the intermolecular interactions in the crystalline state.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the molecular structure.
• Analysis of bond lengths, bond angles, and dihedral angles to describe conformations.
• Identification of hydrogen bonding and other intermolecular forces in the crystal lattice.

Main Results:

• The C ring was found to adopt a chair conformation, while the B ring approximated a half-chair conformation.
• The five-membered D ring exhibited a twist conformation fused to the C ring.
• Aromatic rings A and E were not coplanar, with a dihedral angle of 7.51(1)°.
• O-H⋯O hydrogen bonds formed double chains along the ab plane, with C-H⋯O interactions further stabilizing the crystal structure.

Conclusions:

• The study provides a precise description of the solid-state structure of C25H25ClO2.
• The observed conformations and intermolecular interactions offer insights into the factors governing the packing of this molecule in crystals.