Double-Helix Inorganic Structures

By computationally examining the twists and turns of imaginary inorganic molecules, a multinational research team has determined that simple inorganic compounds should be able to adopt double-helix structures similar to DNA (Angew. Chem. Int. Ed., DOI: 10.1002/anie.201201843). Helical inorganic species are rare and typically involve complex molecular formulas. In addition, an atomic-level structural model for an inorganic double helix hasn’t been proffered until now. Alexander I. Boldyrev of Utah State University, Andrew J. Morris and Chris J. Pickard of University College London, and colleagues found that bulk LiP and Li_xP_x clusters, where x is seven or greater, adopt right- and left-handed double-helix structures in their lowest energy, most stable forms. Boldyrev notes that X-ray crystal structures for bulk LiP and LiAs reported decades ago indicate that the chains of the atoms are spiral and coaxial, but the researchers stopped short of labeling them as double-helix structures. Boldyrev acknowledges that the concept of inorganic double helices is controversial, adding that “we do not think that our double helix could be used by inorganic creatures as DNA on some other planet, but it is quite surprising to us that such unusually simple species might form a double helix.”