Gussenhoven Emily M, Olmstead Marilyn M, Fettinger James C, Balch Alan L
Department of Chemistry, University of California, Davis, CA 95616, USA.
Inorg Chem. 2008 Jun 2;47(11):4570-8. doi: 10.1021/ic702243z. Epub 2008 May 1.
Four polymorphs of IrI(CO)2(OC(CH3)CHC(CH3)N(p-tol)) have been characterized by single crystal X-ray crystallography. While all contain the same molecular unit with no significant structural variations within the molecules, all show different degrees of metallophilic interactions between the planar molecules. Three of these (the amber, the pale yellow, and the orange forms) are stable at room temperature, while the fourth, the L. T. orange form, is only obtained by cooling the orange polymorph. At 77 K, the amber, pale yellow, and L. T. orange polymorphs show intense luminescence. The variations in the luminescence among the polymorphs are considered in the context of the structural differences between them and the nature of the metallophilic interactions between the iridium centers. These results demonstrate how subtle variations in molecular organization can affect the physical properties of planar d8 transition metal compounds, which are an important class of lumiphores.
通过单晶X射线晶体学对IrI(CO)₂(OC(CH₃)CHC(CH₃)N(p - tol))的四种多晶型物进行了表征。虽然所有多晶型物都包含相同的分子单元，分子内没有明显的结构变化，但所有多晶型物在平面分子之间都表现出不同程度的亲金属相互作用。其中三种（琥珀色、浅黄色和橙色晶型）在室温下稳定，而第四种，低温橙色晶型，只能通过冷却橙色多晶型物获得。在77 K时，琥珀色、浅黄色和低温橙色多晶型物表现出强烈的发光。在它们之间结构差异以及铱中心之间亲金属相互作用性质的背景下，考虑了多晶型物之间发光的变化。这些结果表明分子排列的细微变化如何影响平面d⁸过渡金属化合物的物理性质，平面d⁸过渡金属化合物是一类重要的发光体。
