New molecular precursors for AgCu nanoalloy preparation


        Vit Vykoukal^1, Jiri Bursik^2, Pavla Roupcova^2, Vitezslav Halasta, Jiri Pinkas^1^*

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^1 Masaryk University, Faculty of Science, Department of Chemistry, Kotlarska 2, 611 37 Brno, Czech
                                             Republic

        ^2 Institute of Physics of Materials, ASCR, Zizkova 22,616 62 Brno, Czech Republic

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                                       jpinkas@chemi.muni.cz


Abstract:

Nanoparticles preparation by bottom-up methods depends strongly on using molecular precursors and
the type and nature of precursors have a decesive effect of their formation and properties. They
can greatly affect their resulting size, size distribution, shape and optical properties. In case
of Cu, Ag, and Cu/Ag nanoparticles we can observe plasmon resonances and their close connection
with the size, shape and distribution of sizes.We synthetized several new copper precursors by
reduction of Cu(II) salts of carboxylic acids by triphenylphosphine. We characterized the structure
of the new precursors by single crystal X-ray diffraction analyses and nuclear magnetic resonance.
In addition we examined their thermal stability in oleylamine and determined the temperature of
decomposition therefore the minimal temperature for nanoparticles synthesis. CuAg alloy
nanoparticles were prepared by solvothermal hot-injection synthesis from the new precursors based
on Cu(I) complexes. We compared benzoate and phtalate copper(I) complexes as precursors. CuAg
nanoalloys were prepared from [Ag(NH[2]C[12]H[25])[2]]NO[3] and triphenylphospinecopper(I) benzoate
or triphenylphospinecopper(I) phthalate. Nanoalloy from benzoate was oblate, polydispersive and
exhibited two plasmons at 393 and 569 nm. Nanoalloy from phthalate was round, monodispersive and
exhibit one plasmon at 413 nm. We applied new molecular precursors in nanoalloy synthesis and
demonstrated their influence on the final properties.

Acknowledgements. This research has been financially supported by the Ministry of Education, Youth
and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601).

Authors thank the X-ray Diffraction and Bio-SAXS Core Facility of CEITEC.

Keywords: new precursors based on Cu(I), XRD, nanoalloy, copper, silver


Figure 1: Molecular structure of bis(triphenylphosphine)copper(I) benzoate and
tris(triphenylphosphine)copper(I) phthalate