A versatile low temperature synthetic route to Zintl phase precursors: Na4Si4, Na4Ge4 and K4Ge4 as examples.
A versatile low temperature synthetic route to Zintl phase precursors: Na4Si4, Na4Ge4 and K4Ge4 as examples.
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DOI：
10.1039/b913320h
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发表时间：
2009-12-14
期刊：
影响因子：
--
通讯作者：
Kauzlarich SM
中科院分区：
文献类型：
--
作者：
Ma X;Xu F;Atkins TM;Goforth AM;Neiner D;Navrotsky A;Kauzlarich SM
Na4Si4和Na4Ge4是制备无机笼状结构、簇合物和纳米晶体的理想化学前驱体。单斜锌相Na_4Si_4和Na_4Ge_4含有被碱金属阳离子包围的孤立的高四面体[Si4]_4−和[Ge_4]_4−团簇。在本研究中，利用NaH与Si或Ge的低温反应(Na4Si4的温度为420℃，Na4Ge4的温度为270℃)，采用了一种简单的可伸缩的路线来制备组成Na4Si4和Na4Ge4的Zintl相。以KH和Ge为原料，将该方法应用于K4Ge_4，显示了该方法的通用性。通过控制试剂混合方法(手动或球磨)、原料之间的化学计量比、反应温度、加热时间和气体流量等五个因素，研究了特定反应条件对这些锌相纯度的影响。适度的球磨和过量的NaH或KH有利于在420°C(Na4Si4)或270°C(两种M4Ge4化合物，M=Na，K)下形成纯的Na4Si4，Na4Ge4或K4Ge4。对NaH和Ge反应的TG/DSC分析表明，球磨降低了反应温度，确定了生成温度。这种方法提供了大量高质量的Na4Si4和Na4Ge4，而不需要专门的实验室设备，如Schlenk生产线、Nb/Ta容器或弧焊机，从而通过使它们更容易制备来扩大这些相的可及性和化学用途。这种新的合成方法也可以推广到含锂的锌相(LiH是商业上可以得到的)以及其他组成的碱金属-Tetrel锌化合物，如K4Ge9。
Na4Si4 and Na4Ge4 are ideal chemical precursors for inorganic clathrate structures, clusters, and nanocrystals. The monoclinic Zintl phases, Na4Si4 and Na4Ge4, contain isolated homo-tetrahedranide [Si4]4− and [Ge4]4− clusters surrounded by alkali metal cations. In this study, a simple scalable route has been applied to prepare Zintl phases of composition Na4Si4 and Na4Ge4 using the reaction between NaH and Si or Ge at low temperature (420 °C for Na4Si4 and 270 °C for Na4Ge4). The method was also applied to K4Ge4, using KH and Ge as raw materials, to show the versatility of this approach. The influence of specific reaction conditions on the purity of these Zintl phases has been studied by controlling five factors: the method of reagent mixing (manual or ball milled), the stoichiometry between raw materials, the reaction temperature, the heating time and the gas flow rate. Moderate ball-milling and excess NaH or KH facilitate the formation of pure Na4Si4, Na4Ge4 or K4Ge4 at 420 °C (Na4Si4) or 270 °C (both M4Ge4 compounds, M = Na, K). TG/DSC analysis of the reaction of NaH and Ge indicates that ball milling reduces the temperature for reaction and confirms the formation temperature. This method provides large quantities of high quality Na4Si4 and Na4Ge4 without the need for specialized laboratory equipment, such as Schlenk lines, niobium/tantalum containers, or an arc welder, thereby expanding the accessibility and chemical utility of these phases by making them more convenient to prepare. This new synthetic method may also be extended to lithium-containing Zintl phases (LiH is commercially available) as well as to alkali metal-tetrel Zintl compounds of other compositions, e.g. K4Ge9.
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影响因子：
24.2
作者：
Fauchet, Philippe M.
通讯作者：
Fauchet, Philippe M.
纳米碱金属氢化物的化学反应性和热稳定性
影响因子：
2.5
作者：
Fan, Yinheng;Li, Weina;Xu, Jie
通讯作者：
Xu, Jie
DOI：
10.1524/ncrs.2008.0078
发表时间：
2008-01-01
影响因子：
0.3
作者：
Goebel, Thorsten;Prots, Yurii;Haarmann, Frank
通讯作者：
Haarmann, Frank
影响因子：
3.3
作者：
Bobev, S;Sevov, SC
通讯作者：
Sevov, SC
影响因子：
64.8
作者：
Armatas, Gerasimos S.;Kanatzidis, Mercouri G.
通讯作者：
Kanatzidis, Mercouri G.