Carbon-based nanomaterials

Diamondoids are the newest members of carbon-based nanomaterials. They represent the ultimate limit for molecular fragments of bulk diamond and a unique molecular hierarchy. Our high-pressure experiments on a series of diamondoids with systematically varying molecular geometries and dimensionalities, ranging from zero-dimensional (0D) adamantane to 3D [1(2,3)4]pentamantane show a clear dependence of the diamondoids’ bulk moduli to their molecular geometries with 3D [1(2,3)4]pentamantane being the least compressible compared to 0D adamantane which is the most compressible, while 1D and 2D diamondoids fall in between. The connection between nanomaterials’ shape and functionality revealed by our systematic high-pressure study provides guidance in designing nanoscale structures with tunable mechanical strength that implement diamondoids as building blocks. In addition, higher diamondoids were found to display exotic optical and electronic properties and rich chemistry, but are only present in extremely minute concentrations in nature, and have in the past been largely inaccessible to synthetic methods. We propose to combine pressure, temperature, and ultraviolet radiation to explore the formation of higher diamondoids and nanodiamonds using lower diamondoids as precursors and explore whether pressure can encourage the addition of foreign dopants into diamondoids and induce emergent properties such as ferroelectricity and superconductivity in these materials.