One-Dimensional Phosphorus Nanostructures: from Nanorings to Nanohelices.

Phosphorus nanorings and nanohelices-speculated to exist over 20 years ago-have been systematically derived from one parent structure and studied with quantum chemical methods. The (P8 P2 )n nanorings have been recently synthetized inside carbon nanotube templates, and our comprehensive analysis of possible structural arrangements strongly supports the possibility to experimentally determine the closely related (P8 P2 )n nanohelices. The nanohelices possess very low stiffness, suggesting interesting mechanical properties with nano-spring-like behavior.