Nanostructured molecular clusters and solids from heavier group 15 cyanate analogues: A novel route to metal pnictides

点击翻译按钮获取中文摘要

Metal pnictides (compounds containing nitrogen, phosphorus, arsenic, antimony and/or bismuth) are a varied family of solids that adopt a wealth of structures and stoichiometries. Amongst their many applications they have been employed as fumigants, pesticides, flares and, perhaps most notably, as semiconductors. The diversity of their physical and chemical properties makes such compounds interesting for a range of technological applications. However, while many such species can be readily synthesized using a variety of methods, these often come at a high energetic cost. Moreover, the ability to access well defined nanoscale materials or mesostructured solids is still significantly limited by existing technological methods. This is the challenge I propose to address. The goal is to study the use of alternative pnictogen-containing reagents for the synthesis of novel clusters, nanoparticles and structured solids. The proposal focuses on the reactivity of heavier pnictogen-containing analogues of the cyanate anion, PnCO– (Pn = P–Bi) with transition- and post-transition metal salts, as the use of these compounds for the synthesis of solids and molecular clusters is largely unexplored. The first objective is to extend the chemistry of the heavier group 15 analogues of cyanate to target the synthesis of SbCO– and BiCO–. Then, solution-phase metathesis reactions between heavier group 15 cyanate analogues (PnCO–) with a variety of transition- and post-transition metal salts will be conducted, with the aim of developing a novel bottom-up approach to metal pnictides. Herein, the main focus is establishing control over solid formation, with a particular focus on generating well-defined nanoparticles and structured solids as dimensionally reduced semiconductor structures such as nanoparticles and quantum dots are impacting a diverse set of scientific and technological fields (e.g. bioassaying or optoelectronic devices). Finally, the cyanate analogues should be suitable precursors for the synthesis of magic-sized molecular clusters and quantum dots (QDs). The thermal treatment of such clusters may also be used for the nucleation of monodisperse samples of group III/V QDs, a family of compounds that have thus far proven very challenging synthetically.