Vectorial noncovalent synthesis of bendable organic crystals through dynamic dislocation

Area of Science:

• Materials Science
• Organic Electronics
• Crystallography

Background:

• Organic molecular crystals are vital for integrated optoelectronic chips, enabling precise optical signal steering.
• Current methods struggle to create bent molecular crystals with controlled angles and intact interfaces.

Purpose of the Study:

• To develop a universal strategy for fabricating organic molecular crystals with controllable bending angles.
• To address the limitations of existing methods in achieving desired bent geometries without structural damage.

Main Methods:

• A "molecular cocrystal" strategy was employed, introducing directional charge-transfer non-covalent interactions.
• These interactions weaken original molecular forces, promoting spontaneous transition from crystal slippage to bending.
• The method was applied to synthesize diverse bent crystals and hierarchical microstructures.

Main Results:

• Successfully synthesized self-assembled bent crystals with precise angles (61.8°–85.0°) without compromising structural integrity.
• Demonstrated the construction of hierarchical bent microstructures featuring 2 to 6 bends.
• Observed excitation position-dependent anisotropic optical behaviors in the bent crystals.

Conclusions:

• The molecular cocrystal strategy provides a versatile pathway for designing bent crystals with tailored angles.
• This approach lays a foundation for advanced on-chip organic optoelectronics and photonics switches.
• The developed bent crystals exhibit tunable optical properties suitable for photonic applications.