Huba Zachary J, Carpenter Everett E
Department of Chemistry, Virginia Commonwealth University, 1001 W. Main Street, Richmond, VA 23284, USA.
Dalton Trans. 2014 Aug 28;43(32):12236-42. doi: 10.1039/c4dt01207k.
Single molecule precursors can help to simplify the synthesis of complex alloys by minimizing the amount of necessary starting reagents. However, single molecule precursors are time consuming to prepare with very few being commercially available. In this study, a simple precipitation method is used to prepare Fe, Co, and Ni fumarate and succinate complexes. These complexes were then thermally decomposed in an inert atmosphere to test their efficiency as single molecule precursors for the formation of metal carbide phases. Elevated temperature X-ray diffraction was used to identify the crystal phases produced upon decomposition of the metal dicarboxylate complexes. Thermogravimetric analysis coupled with an infrared detector was used to identify the developed gaseous decomposition products. All complexes tested showed a reduction from the starting M(2+) oxidation state to the M(0) oxidation state, upon decomposition. Also, each complex tested showed CO2 and H2O as gaseous decomposition products. Nickel succinate, iron succinate, and iron fumarate complexes were found to form carbide phases upon decomposition. This proves that transition metal dicarboxylate salts can be employed as efficient single molecule precursors for the formation of metal carbide crystal phases.
单分子前驱体可以通过减少所需起始试剂的量来帮助简化复杂合金的合成。然而，单分子前驱体的制备耗时，且市面上可买到的很少。在本研究中，采用一种简单的沉淀法来制备富马酸铁、富马酸钴、富马酸镍以及琥珀酸铁、琥珀酸钴、琥珀酸镍配合物。然后将这些配合物在惰性气氛中进行热分解，以测试它们作为形成金属碳化物相的单分子前驱体的效率。利用高温X射线衍射来鉴定金属二羧酸盐配合物分解时产生的晶相。热重分析结合红外探测器来鉴定产生的气态分解产物。所有测试的配合物在分解时均显示从起始的M(2+)氧化态还原为M(0)氧化态。此外，每个测试的配合物均显示二氧化碳和水为气态分解产物。发现琥珀酸镍、琥珀酸铁和富马酸铁配合物在分解时会形成碳化物相。这证明过渡金属二羧酸盐可作为形成金属碳化物晶相的有效单分子前驱体。
