Controlled Synthesis of Ternary II−II‘−VI Nanoclusters and the Effects of Metal Ion Distribution on Their Spectral Properties

The reaction of [(3,5-Me2-C5H3N)2Zn(ESiMe3)2] (E = Se, Te) with cadmium(II) acetate in the presence of PhESiMe3
and PnPr3 at low temperature leads to the formation of single crystals of the ternary nanoclusters [ZnxCd10-xE4-(EPh)12(PnPr3)4] [E = Se, x = 1.8 (2a), 2.6 (2b); Te, x = 1.8 (3a), 2.6 (3b)] in good yield. The clusters [Zn3Hg7Se4(SePh)12(PnPr3)4] (4) and [Cd3.7Hg6.3Se4(SePh)12(PnPr3)4] (5) can be accessed by similar reactions involving
[(3,5-Me2-C5H3N)2Zn(SeSiMe3)2] or [(N,N‘-tmeda)Cd(SeSiMe3)2] (1) and mercury(II) chloride. The metal silylchalcogenolate reagents are efficient delivery sources of {ME2} in cluster synthesis, and thus, the metal ion content
of these clusters can be readily moderated by controlling the reaction stoichiometry. The reaction of cadmium
acetate with [(3,5-Me2-C5H3N)2Zn(SSiMe3)2], PhSSiMe3, and PnPr3 affords the larger nanocluster [Zn2.3Cd14.7S4(SPh)26(PnPr3)2] (6). The incorporation of Zn(II) into {Cd10E} (E = Se, Te) and Zn(II) or Cd(II) into {Hg10Se}
nanoclusters results in a significant blue shift in the energy of the first “excitonic” transition. Solid-state thermolysis
of complexes 2 and 3 reveals that these clusters can be used as single-source precursors to bulk ternary ZnxCd1-xE
materials as well as larger intermediate clusters and that the metal ion ratio is retained during these reactions.

[(3,5-二甲基吡啶)₂Zn(ESiMe₃)₂]（E=硒(Se),碲(Te)）与乙酸镉(II)在苯基（Ph）三甲基硅基硫族醇盐（PhESiMe₃）及三正丙基膦（PnPr₃）存在下于低温反应，可高产率得到三元纳米簇[ZnₓCd₁₀₋ₓE₄(EPh)₁₂(PnPr₃)₄]的单晶，其中E为Se时x=1.8（产物2a）、x=2.6（产物2b）；E为Te时x=1.8（产物3a）、x=2.6（产物3b）。簇合物[Zn₃Hg₇Se₄(SePh)₁₂(PnPr₃)₄]（4）与[Cd₃.₇Hg₆.₃Se₄(SePh)₁₂(PnPr₃)₄]（5）可通过类似反应制备：以[(3,5-二甲基吡啶)₂Zn(SeSiMe₃)₂]或[(N,N'-四甲基乙二胺（TMEDA）)合镉(II)双(三甲基硅基硒醇盐)]（1）与氯化汞(II)反应即可得到。上述金属甲硅烷基硫族醇盐试剂是簇合成中{ME₂}单元的高效给体源，因此可通过调控反应计量比，轻松调节这类纳米簇的金属离子组成。乙酸镉与[(3,5-二甲基吡啶)₂Zn(SSiMe₃)₂]、苯基（Ph）三甲基硅基硫醇盐（PhSSiMe₃）及三正丙基膦反应，可得到更大尺寸的纳米簇[Zn₂.₃Cd₁₄.₇S₄(SPh)₂₆(PnPr₃)₂]（6）。将Zn(II)掺入{Cd₁₀E}（E=Se,Te）纳米簇，或将Zn(II)或Cd(II)掺入{Hg₁₀Se}纳米簇，均可使体系的第一“激子”跃迁能量发生显著蓝移。对产物2和3进行固相热解实验表明，这类纳米簇可用作制备体相三元ZnₓCd₁₋ₓE材料及更大尺寸中间簇的单源前驱体，且反应过程中金属离子比例得以保留。