Köhler Jürgen, Friedrich Holger, Whangbo Myung-Hwan, Villesuzanne Antoine
Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany.
J Am Chem Soc. 2005 Sep 21;127(37):12990-6. doi: 10.1021/ja053280x.
A new phase PtIn62O, a filled variant of PtIn62, and the solid solution PtIn6(2-x)(GeO4)xOx/2 (0 < or = x < or = 2) were prepared and characterized. Single-crystal structure refinements show that PtIn62O is isotypic with the mineral, sulfohalite Na6FCl(SO4)2, and crystallizes in the space group Fmm (Z = 4) with a = 1006.0(1) pm. The building units of PtIn62O are isolated [PtIn6]10+ octahedra and (GeO4)4- tetrahedra, and the isolated O2- ions occupy the centers of the In6 octahedra made up of six adjacent PtIn6 octahedra. The lattice parameter of the solid solution PtIn6(2-x)(GeO4)xOx/2 (0 < or = x < or = 2) varies gradually from a = 1001.3(1) pm at x = 0 to a = 1006.0(1) pm at x = 2, and the color of the solid solution changes gradually from black (x = 0) to red (x = 1) to yellow (x = 2). The cause for the gradual color change was examined by performing density functional theory electronic structure calculations for the end members PtIn62 and PtIn62O. Our analysis indicates that an oxygen atom at the center of a In6 octahedron cuts the In 5p/In 5p bonding interactions between adjacent [PtIn6]10+ octahedra thereby raising the bottom of the conduction bands, and the resulting quantum dot effect is responsible for the color change.
制备并表征了一个新相PtIn₆₂O，它是PtIn₆₂的填充变体，以及固溶体PtIn₆(₂₋ₓ)(GeO₄)ₓOₓ/₂(0≤x≤2)。单晶结构精修表明，PtIn₆₂O与矿物氟氯硫钠矿Na₆FCl(SO₄)₂同型，在空间群Fmm(Z = 4)中结晶，a = 1006.0(1) pm。PtIn₆₂O的结构单元是孤立的[PtIn₆]¹⁰⁺八面体和(GeO₄)⁴⁻四面体，孤立的O²⁻离子占据由六个相邻的PtIn₆八面体组成的In₆八面体的中心。固溶体PtIn₆(₂₋ₓ)(GeO₄)ₓOₓ/₂(0≤x≤2)的晶格参数从x = 0时的a = 1001.3(1) pm逐渐变化到x = 2时的a = 1006.0(1) pm，固溶体的颜色从黑色(x = 0)逐渐变为红色(x = 1)再变为黄色(x = 2)。通过对端成员PtIn₆₂和PtIn₆₂O进行密度泛函理论电子结构计算，研究了颜色逐渐变化的原因。我们的分析表明，In₆八面体中心的一个氧原子切断了相邻[PtIn₆]¹⁰⁺八面体之间的In 5p/In 5p键相互作用，从而提高了导带底部，由此产生的量子点效应导致了颜色变化。
