Metal Carbonyl Cluster Synthesis in Nanocages: Spectroscopic Evidence of Intermediates in the Formation of Ir4(CO)12 in Zeolite NaY
Metal Carbonyl Cluster Synthesis in Nanocages: Spectroscopic Evidence of Intermediates in the Formation of Ir4(CO)12 in Zeolite NaY
复制标题
纳米笼中金属羰基簇的合成：NaY 沸石中形成 Ir4(CO)12 中间体的光谱证据
DOI：
10.1021/jp037100m
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发表时间：
2004
影响因子：
3.3
通讯作者：
B. Gates
中科院分区：
文献类型：
--
作者：
F. Li;B. Gates
用扩展X射线吸收精细结构(EXAFS)和原位红外光谱(IR)研究了Ir(CO)2(Acac)前驱体在NaY分子筛超笼中组装成Ir4(CO)12的过程。结果表明，沸石的前处理条件对Ir4(CO)12的生成过程有显著的影响。当沸石初始大量脱水时，红外光谱和EXAFS光谱都观察到了形成Ir4(CO)12(近似为Ir2(CO)8)的二聚体中间体。相反，当沸石最初含有大量的水时，生成的Ir4团簇的形成速度比脱水沸石中的快，并且没有观察到中间产物的证据。结果表明，与在溶液中不同，在有限的空间中合成沸石纳米树脂如何在没有溶剂的情况下提供了控制和阐明化学的机会。
The assembly of Ir4(CO)12 from Ir(CO)2(acac) precursors in the supercages of zeolite NaY was investigated by extended X-ray absorption fine structure (EXAFS) and in-situ infrared (IR) spectroscopies. The data show that the conditions of pretreatment of the zeolite significantly affect the formation process of Ir4(CO)12. When the zeolite was initially largely dehydrated, so that the precursor molecules were well dispersed in the zeolite cages, dimeric intermediates in the formation of Ir4(CO)12 (approximated as Ir2(CO)8) were observed by both IR and EXAFS spectroscopies. In contrast, when the zeolite initially contained a substantial amount of water, the resultant Ir4 clusters were formed faster than those in dehydrated zeolite, and evidence of intermediates was not observed. The results show how synthesis in the confined spaces of the zeolite nanoporesin the absence of solventsaffords opportunities to control and elucidate the chemistry, different from that in solution.