A new combination to form a solid solution: a solid solution consisting of a stabilized phenoxyl radical and its...

Area of Science:

• Materials Science
• Crystallography
• Organic Chemistry

Background:

• Solid solutions offer tunable material properties.
• Understanding molecular packing in solid solutions is crucial for materials design.
• The 2,4,6-tris(4-tert-butylphenyl)phenoxyl radical (1M) and its methoxy analogue (1OMe) are suitable for forming crystalline structures.

Purpose of the Study:

• To investigate the formation and structural characteristics of solid solutions between 1M and 1OMe.
• To determine how molecular conformation and crystal packing are influenced by the composition of the solid solutions.
• To explore the crystallographic behavior of the phenoxyl radical in solid solutions.

Main Methods:

• Single-crystal X-ray diffraction was employed to analyze the crystal structures of the solid solutions.
• Controlled co-crystallization techniques were used to prepare the α and β solid solutions.
• Spectroscopic methods were utilized to characterize the components and their interactions.

Main Results:

• Two distinct solid solutions, designated α and β, were successfully formed between 1M and 1OMe.
• The β solid solution (1M:1OMe = 0.002:0.998) is isomorphic with pure 1OMe, with molecules adopting the preferred 1OMe conformation.
• The α solid solution (1M:1OMe = 0.80:0.20) exhibits molecular conformations characteristic of 1M, suggesting a different packing arrangement.

Conclusions:

• The crystal structure of solid solutions is significantly influenced by the dominant molecular component.
• The conformational preferences of the individual molecules dictate the packing in the solid state.
• The inability to crystallize pure 1M as a monomer prevents direct comparison for isomorphism with the α phase.