Extending carbon chemistry at high-pressure by synthesis of CaC2 and Ca3C7 with deprotonated polyacene- and para-poly(indenoindene)-like nanoribbons

Saiana Khandarkhaeva; Timofey Fedotenko; Alena Aslandukova; Fariia Iasmin Akbar; Maxim Bykov; Dominique Laniel; Andrey Aslandukov; Uwe Ruschewitz; Christian Tobeck; Björn Winkler; Stella Chariton; Vitali Prakapenka; Konstantin Glazyrin; Carlotta Giacobbe; Eleanor Lawrence Bright; Maxim Belov; Natalia Dubrovinskaia; Leonid Dubrovinsky

doi:10.1038/s41467-024-47138-2

Extending carbon chemistry at high-pressure by synthesis of CaC₂ and Ca₃C₇ with deprotonated polyacene- and para-poly(indenoindene)-like nanoribbons

Nat Commun. 2024 Apr 2;15(1):2855. doi: 10.1038/s41467-024-47138-2.

Authors

Saiana Khandarkhaeva^{1

2}, Timofey Fedotenko³, Alena Aslandukova¹, Fariia Iasmin Akbar¹, Maxim Bykov⁴, Dominique Laniel^{2

5}, Andrey Aslandukov², Uwe Ruschewitz⁴, Christian Tobeck⁴, Björn Winkler⁶, Stella Chariton⁷, Vitali Prakapenka⁷, Konstantin Glazyrin³, Carlotta Giacobbe⁸, Eleanor Lawrence Bright⁸, Maxim Belov⁹, Natalia Dubrovinskaia^{2

9}, Leonid Dubrovinsky¹⁰

Affiliations

¹ Bayerisches Geoinstitut, University of Bayreuth, Universitätstraβe 30, 95440, Bayreuth, Germany.
² Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography University of Bayreuth, Universitätstraβe 30, 95440, Bayreuth, Germany.
³ Deutsches Elektronen-Synchrotron DESY, Notkestraße. 85, 22607, Hamburg, Germany.
⁴ Institute of Inorganic Chemistry, University of Cologne, Greinstraße 6, 50939, Cologne, Germany.
⁵ Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.
⁶ Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, 60438, Frankfurt, Germany.
⁷ Center for Advanced Radiation Sources, The University of Chicago, 5640 S. Ellis, 60637, Chicago, IL, USA.
⁸ European Synchrotron Radiation Facility, CS 40220, 38043, Grenoble, Cedex 9, France.
⁹ Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83, Linköping, Sweden.
¹⁰ Bayerisches Geoinstitut, University of Bayreuth, Universitätstraβe 30, 95440, Bayreuth, Germany. leonid.dubrovinsky@uni-bayreuth.de.

Abstract

Metal carbides are known to contain small carbon units similar to those found in the molecules of methane, acetylene, and allene. However, for numerous binary systems ab initio calculations predict the formation of unusual metal carbides with exotic polycarbon units, [C₆] rings, and graphitic carbon sheets at high pressure (HP). Here we report the synthesis and structural characterization of a HP-CaC₂ polymorph and a Ca₃C₇ compound featuring deprotonated polyacene-like and para-poly(indenoindene)-like nanoribbons, respectively. We also demonstrate that carbides with infinite chains of fused [C₆] rings can exist even at conditions of deep planetary interiors ( ~ 140 GPa and ~3300 K). Hydrolysis of high-pressure carbides may provide a possible abiotic route to polycyclic aromatic hydrocarbons in Universe.