LPCNO, Université de Toulouse, CNRS, INSA, UPS, 135 avenue de Rangueil, 31077 Toulouse, France.
Dalton Trans. 2018 Oct 30;47(42):15114-15120. doi: 10.1039/c8dt02942c.
The synthesis of iron germanide nanoparticles at the nanoscale is a challenging task. Here, we describe the preparation of nanocrystals of the hexagonal Fe1.67Ge phase via the thermolysis of single source precursors [{iPrNC(tBu)NiPr}RGe]Fe(CO)4 (where R = Cl, N(SiMe3)2) under mild conditions (200 °C). These bimetallic precursors and the corresponding germylenes [{iPrNC(tBu)NiPr}RGe] were fully characterized by spectroscopic techniques as well as single crystal X-ray diffraction. While the structural features of the molecular species were shown to be almost identical, the results of the thermolysis were highly dependent on the nature of R. When R = Cl, multimodal size distributions and non-controlled phases were obtained. In contrast, the thermolysis of [{iPrNC(tBu)NiPr}{N(SiMe3)2}Ge]Fe(CO)4 yielded pure ferromagnetic Fe1.67Ge nanoparticles with a mean diameter close to 6 nm and a narrow size distribution (<12%). These results were rationalized in terms of Ge-substituent bond energy thanks to a computational study.
在纳米尺度下合成铁锗纳米粒子是一项具有挑战性的任务。在这里，我们描述了通过温和条件（200°C）下的单源前体[{iPrNC(tBu)NiPr}RGe]Fe(CO)4（其中 R = Cl，N(SiMe3)2）的热解来制备六方相 Fe1.67Ge 纳米晶。这些双金属前体和相应的锗烷[{iPrNC(tBu)NiPr}RGe]通过光谱技术以及单晶 X 射线衍射进行了充分的表征。虽然分子物种的结构特征几乎相同，但热解的结果高度依赖于 R 的性质。当 R = Cl 时，得到了多模态尺寸分布和非受控相。相比之下，[{iPrNC(tBu)NiPr}{N(SiMe3)2}Ge]Fe(CO)4 的热解得到了纯铁磁 Fe1.67Ge 纳米粒子，平均直径接近 6nm，尺寸分布较窄（<12%）。这些结果通过计算研究根据 Ge 取代基键能进行了合理化。
