New polymorph of 2,6-di-methyl-phenol

Area of Science:

• Crystallography
• Solid-state chemistry
• Materials science

Background:

• The title compound, C8H10O, exists as a racemic monoclinic polymorph previously documented in scientific literature.
• Polymorphism, the ability of a solid material to exist in more than one crystal form, is crucial in determining material properties.

Purpose of the Study:

• To redetermine the crystal structure of the known racemic monoclinic polymorph of C8H10O.
• To report and characterize a newly discovered enantiopure orthorhombic polymorph of the same compound.
• To compare the intermolecular interactions and crystal packing of the two polymorphs.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine and confirm the crystal structures of both polymorphs.
• Crystallographic data analysis was performed to identify and compare structural features, including hydrogen bonding and molecular packing.

Main Results:

• The crystal structure of the racemic monoclinic polymorph of C8H10O was successfully redetermined.
• A novel enantiopure orthorhombic polymorph of C8H10O was identified and characterized.
• Both polymorphs feature strong one-dimensional hydrogen-bonded chains, showing high similarity.
• Significant differences were observed in the arrangement and packing of these hydrogen-bonded chains between the two crystal forms.

Conclusions:

• The study confirms the existence of two distinct polymorphs of C8H10O: a racemic monoclinic form and a new enantiopure orthorhombic form.
• While the fundamental hydrogen bonding motifs are conserved, the distinct crystal packing in each polymorph suggests varied solid-state properties.
• Understanding these polymorphic differences is essential for controlling the material's behavior in different applications.