Exploiting In Situ Solid-State NMR for the Discovery of New Polymorphs during Crystallization Processes

Area of Science:

• Solid-state chemistry
• Materials science
• Nuclear Magnetic Resonance (NMR) spectroscopy

Background:

• Polymorphism, the ability of a solid material to exist in multiple crystalline forms, significantly impacts material properties.
• Understanding and controlling polymorphism is crucial for various applications, including pharmaceuticals and materials design.
• Traditional methods for polymorph discovery can be time-consuming and may miss transient or metastable forms.

Purpose of the Study:

• To introduce a novel solid-state Nuclear Magnetic Resonance (NMR) technique for in situ monitoring of crystallization processes.
• To demonstrate the technique's capability in discovering new polymorphic forms of molecular solids.
• To validate the method through the identification of new forms in specific chemical systems.

Main Methods:

• Development and application of an advanced solid-state NMR spectroscopy method.
• In situ monitoring of crystallization processes to observe structural evolution over time.
• Characterization of newly discovered solid forms using spectroscopic and crystallographic analyses.

Main Results:

• Successful discovery of two new polymorphs of methyldiphenylphosphine oxide.
• Identification of a new solid form within the 1,10-dihydroxydecane/urea system.
• Demonstration of the solid-state NMR technique's efficacy in revealing previously unknown polymorphic structures.

Conclusions:

• The developed in situ solid-state NMR technique is a powerful tool for discovering new polymorphic forms.
• This method offers a significant advancement in understanding crystallization pathways and solid-state transformations.
• The findings open new avenues for exploring and controlling polymorphism in molecular solids.