ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Thermolysis of the NaCu[B₁₀H₁₀]/NaOH·SiO₂ system: encapsulation of in situ formed Cu₃Si into a sodium boron silicate matrix

Elena A. Malinina, Ivan I. Myshletsov, Grigorii A. Buzanov, Irina V. Kozerozhets, Svetlana E. Nikiforova, Varvara V. Avdeeva, and Nikolay T. Kuznetsov

Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, Russia

E-mail: avdeeva.varvara@mail.ru

Received: 10 January 2024  Accepted: 25 April 2024

Abstract:

The paper proposes a fundamentally new approach to the introduction of copper(I) ions into sodium liquid glass NaOH·SiO₂, as well as to the solid-phase synthesis of tricopper silicide Cu₃Si. The possibility of forming a composite based on a sodium boron silicate matrix and tricopper silicide Cu₃Si formed in situ during the thermolysis of the NaCu^I[B₁₀H₁₀]/NaOH·SiO₂ system is shown. The latter has been obtained by a cation metathesis when copper(I) complex {(Et₃NH)Cu^I[B₁₀H₁₀]}_n has been allowed to react with a 30% solution of sodium liquid glass (NaOH·SiO₂). Thermolysis of NaCu^I[B₁₀H₁₀]/NaOH·SiO₂ has been carried out in an argon atmosphere at 900 °C. It is established that this process is accompanied by a redox transformation and leads to the formation of binary copper compound Cu₃Si encapsulated in a sodium boron silicate matrix. The initial system and the annealed product have been identified by a complex of physicochemical methods: TGA, IR spectroscopy, X-ray powder diffraction, and X-ray spectral fluorescence. The morphology of the product has been studied.

Keywords: Sodium liquid glass; Tricopper silicide; Boron cluster anions; Thermolysis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03490-7

Chemical Papers 78 (9) 5697–5704 (2024)