Vol. 13, Issue 5 (2025)

Conventional synthetic diamond production is dominated by high-pressure high-temperature (HPHT) and chemical vapor deposition (CVD) methods, both of which require diamond seeds or nucleation centers to initiate growth ^[1-4]. While these strategies are mature and scalable, their reliance on seed crystals limits innovation in designing new nucleation pathways. In this theoretical work, we propose a seed-independent synthetic route that uses organic chemistry to pre-assemble diamondoid-like sp³ frameworks capable of nucleating diamond growth. The designed pathway begins with the condensation of tetrachloromethane (CCl?) and cyclobutane under elevated temperature and pressure, eliminating HCl and generating a pentacyclic pyramido-pentane intermediate (C?H?). Through successive ring fusions and rearrangements, the framework evolves toward a decacyclic octahedral “hexane” (C?) cage, whose local bonding geometry closely resembles the octahedral coordination of diamond’s cubic lattice ^[5-7]. Such molecular architectures are reminiscent of diamondoids and can act as pre-organized, atomically precise nuclei ^[8-10].