High-Pressure Selective Topotactic Synthesis of Ordered Trans-Polymeric CS2 in a Zeolite

Year: 2025

Authors: Santoro M., Romi S., Alabarse F.G., Hermet P., Haines J.

Autors Affiliation: CNR, Ist Nazl Ott INO, I-50019 Sesto Fiorentino, Italy; European Lab Non Linear Spect LENS, I-50019 Sesto Fiorentino, Italy; Univ Firenze, Dipartimento Chim Ugo Shiff, I-50019 Sesto Fiorentino, Italy; Elettra Sincrotrone Trieste, I-34149 Trieste, Italy; Univ Montpellier, Inst Charles Gerhardt Montpellier ICGM, CNRS, ENSCM, F-34293 Montpellier, France.

Abstract: High-pressure polymerization of CS2 leads to structurally and stoichiometrically disordered solids, making characterization of the products and of reaction mechanisms challenging. This is due to the multiplicity of chemical pathways that CS2 is subject to in the free space. We reduced this multiplicity by constraining polymerization in a confined space. We inserted liquid CS2 in the one-dimensional pores of the all-siliceous zeolite Theta-One, subjected the mixture to maximum temperatures and pressures of 250 degrees C and 14 GPa, and recovered a darkened sample at ambient conditions. Synchrotron X-ray diffraction was performed on the materials. Full structural refinements, using ab initio calculated structures as starting models, show that CS2 in the zeolite undergoes selective topotactic polymerization, resulting in the ordered trans-isomer of the long-sought-after Bridgman’s black polymer (-(C=S)-S-) n . We provide physical insight into the reaction mechanism by proposing that it consists of a molecular bending followed by addition. The trans-polymer forms spontaneously from the unstable, confined monomer upon relaxation in ab initio calculations.

Journal/Review: INORGANIC CHEMISTRY

Volume: 64 (25)      Pages from: 12762  to: 12767

More Information: The synchrotron X-ray diffraction experiments were performed at the Xpress beamline from Elettra Sincrotrone Trieste (proposal number: 20225030). We also thank Elettra for providing us with the CS2 sample. M.S. and S.R. acknowledge the project SALUS, provided by the Fondazione Cassa di Risparmio di Firenze, and the project European Union – NextGeneration EU, Integrated infrastructure initiative in Photonic and Quantum Sciences – I-PHOQS (IR0000016, ID D2B8D520, CUP B53C22001750006). All the authors acknowledge Marco Fabbiani and Damian Paliwoda for their assistance during preliminary measurements on the TON/CS2 mixtures.
KeyWords: Carbon-disulfide; High-temperature; Crystal; Dioxide
DOI: 10.1021/acs.inorgchem.5c01685