Abstract
Synthesis of well-ordered reduced dimensional carbon solids with extended bonding remains a challenge. For example, few single-crystal organic monomers react under topochemical control to produce single-crystal extended solids. We report a mechanochemical synthesis in which slow compression at room temperature under uniaxial stress can convert polycrystalline or single-crystal benzene monomer into single-crystalline packings of carbon nanothreads, a one-dimensional sp3 carbon nanomaterial. The long-range order over hundreds of microns of these crystals allows them to readily exfoliate into fibers. The mechanochemical reaction produces macroscopic single crystals despite large dimensional changes caused by the formation of multiple strong, covalent C-C bonds to each monomer and a lack of reactant single-crystal order. Therefore, it appears not to follow a topochemical pathway, but rather one guided by uniaxial stress, to which the nanothreads consistently align. Slow-compression room-temperature synthesis may allow diverse molecular monomers to form single-crystalline packings of polymers, threads, and higher dimensional carbon networks.
| Original language | English |
|---|---|
| Pages (from-to) | 16343-16349 |
| Number of pages | 7 |
| Journal | Journal of the American Chemical Society |
| Volume | 139 |
| Issue number | 45 |
| DOIs | |
| State | Published - Nov 15 2017 |
Funding
This work was supported as part of the Energy Frontier Research in Extreme Environments (EFree) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science under award number DE-SC0001057. Sample synthesis was performed at the Spallation Neutrons and Pressure (SNAP) beamline at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. In situ X-ray diffraction experiments were performed at the High Pressure Collaborative Access Team (HPCAT) beamline 16 ID-B at the Advanced Photon Source (APS), Argonne National Laboratory (ANL). HPCAT operations are supported by DOE-NNSA under Award No. DE-NA0001974, with partial instrumentation funding by the National Science Foundation (NSF). We thank Jesse Smith, Ross Hrubiak, and Rich Ferry for their assistance during beamline data collection. In situ Raman data was collected at the High Pressure Synergetic Consortium (HPSynC) facilities. We thank HPSynC and Timothy Strobel (Carnegie Institution of Washington) for providing gas controllers. Hemant Yennawar assisted with in-house X-ray diffraction experiments at Penn State. Steven Juhl assisted with optical microscopy measurements at Penn State. Crystallographic pdb files of benzene phase II are available in the Supporting Information.