Dibenzyl Diselenideas a Monitorable, Atom-EfficientSe Source for the Synthesis of Cu₃PSe₄ Nanoparticles

Complex ternary composition nanoparticles (NPs) are highly desired for a range of potential applications, but their syntheses often rely on empirical syntheses rather than designed, ideally mechanism-based, syntheses. Here, we focus on colloidal Cu₃PSe₄ nanoparticles as a model system, one we have previously prepared from Cu_3–<i>x</i>P and solid Se. However, in that prior system quantitatively following the conversion of solid Se into the Cu₃PSe₄ product is problematic, in turn meaning that the balanced reaction stoichiometry and, hence, mechanistic insights remain elusive. Herein, we show that dibenzyl diselenide (Bn₂Se₂) has considerable utility in the synthesis of Cu₃PSe₄ NPs. Using Cu_3–<i>x</i>P plus 2 equiv of Bn₂Se₂ yields Cu₃PSe₄ as the main NP product. The benzyl moiety (PhCH₂−), coupled with NMR and gas chromatography–mass spectrometry (GC-MS) handles, establishes that benzyl loss and toluene (PhCH₃) gain are a monitorable proxy for net Se⁰₂ delivery when the facile, net two H^• donor 9,10-dihydroanthracene is added. The experiments performed and the results obtained help to further lay the groundwork for the expanded use of Bn₂Se₂ as a Se⁰₂ delivery reagent for the syntheses of Se-containing materials. More broadly, the results herein support the use of molecular precursors, chosen based on previously established chemistry, that allow trackable, quantifiable reaction products in NP and related material syntheses.