4-Vinylbenzoic acid and 9-vinylanthracene

Area of Science:

• Crystallography
• Materials Science
• Organic Chemistry

Background:

• Styrene analogues are important in polymer science and organic synthesis.
• Understanding their solid-state structures provides insights into reactivity and physical properties.
• Previous studies have explored related aromatic vinyl compounds.

Purpose of the Study:

• To determine and compare the crystal structures of 4-vinylbenzoic acid and 9-vinylanthracene.
• To investigate the influence of temperature on their molecular conformations and bond lengths.
• To analyze the packing arrangements and intermolecular interactions in the solid state.

Main Methods:

• Single-crystal X-ray diffraction was employed to analyze the crystal structures.
• Data collection was performed at variable temperatures (108 K, 123 K, and 293 K).
• Crystallographic data were processed to determine atomic coordinates, bond lengths, and angles.

Main Results:

• 4-vinylbenzoic acid forms dimers via carboxylate hydrogen bonding, with the vinyl group nearly coplanar to the phenyl ring.
• 9-vinylanthracene exhibits antiparallel stacking of anthracene planes, with the vinyl group nearly perpendicular to the anthracene core.
• A significant temperature-dependent shortening of the vinyl C=C bond length was observed in 4-vinylbenzoic acid, attributed to thermal motion bias.

Conclusions:

• The crystal packing and vinyl group orientation are significantly influenced by the specific aromatic system and functional groups.
• Temperature-dependent structural analysis reveals distinct thermal motion behaviors in these styrene analogues.
• These findings contribute to a deeper understanding of structure-property relationships in vinyl-substituted aromatic compounds.