Single Crystalline Diamond Nanowire

Single Crystalline Diamond Nanowire

A single-crystal-to-single-crystal topochemical polymerization strategy has enabled the synthesis of high-quality diamond nanowire single crystals with lateral dimensions approaching the hundred-micrometre scale. Precise control of molecular packing and reaction conditions preserves long-range crystallinity during the pressure-induced transformation, overcoming a long-standing challenge in diamond nanostructure synthesis.

Molecular pre-organization is achieved through directional carboxyl–carboxyl hydrogen bonding in 1-naphthoic acid, combined with an optimal slip angle of 21.6°, which promotes efficient pre-stacking. Subsequent treatment under 20 GPa and annealing at 573 K suppresses defect formation and maintains crystallographic continuity throughout polymerization. The resulting nanowires adopt a lonsdaleite-like diamond structure and reach sizes of ~140 × 100 × 20 μm, representing the largest diamond nanowire single crystals reported to date and enabling macroscopic property measurements.

Solid-state NMR and complementary analyses reveal carbon-site selectivity and identify a cascade of Diels–Alder reactions as the dominant polymerization mechanism. Remarkably, the diamond nanowire single crystals remain stable under ambient conditions, establishing a viable pathway toward functional diamond nanowire architectures for thermal management in communications, quantum technologies, and advanced energy systems.