Mechanically compliant single crystals of a stable organic radical†

Mechanically compliant organic crystals are the foundation of the development of future flexible, light-weight single-crystal electronics, and this requires reversibly deformable crystalline organic materials with permanent magnetism. Here, we report and characterize the first instance of a plastically bendable single crystal of a permanent organic radical, 4-(4 '-cyano-2 ',3 ',4 ',5 '-tetrafluorophenyl)-1,2,3,5-dithiadiazolyl. The weak interactions between the radicals render single crystals of the beta phase of this material exceedingly soft, and the S-N interactions facilitate plastic bending. EPR imaging of a bent single crystal reveals the effect of deformation on the three-dimensional spin density of the crystal. The unusual mechanical compliance of this material opens prospects for exploration into flexible crystals of other stable organic radicals towards the development of flexible light-weight organic magnetoresistance devices based on weak, non-hydrogen-bonded interactions in molecular crystals.

Automated summary

This study reports and characterizes the first plastically bendable single crystal of a permanent organic radical, which exhibits exceedingly soft characteristics due to weak interactions between radicals and S-N interactions. EPR imaging of the bent single crystal reveals the impact of deformation on the crystal's three-dimensional spin density. The unusual mechanical compliance of this material opens prospects for the development of flexible light-weight organic magnetoresistance devices based on weak, non-hydrogen-bonded interactions in molecular crystals.