The Extra-Framework Sub-Lattice of the Metal-Organic Framework MIL-110: A Solid-State NMR Investigation
The Extra-Framework Sub-Lattice of the Metal-Organic Framework MIL-110: A Solid-State NMR Investigation
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DOI：
10.1002/chem.200801856
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发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Taulelle, Francis
中科院分区：
文献类型：
--
作者：
Haouas, Mohamed;Volkringer, Christophe;Taulelle, Francis
用固体核磁共振波谱研究了1，3，5-苯三羧酸铝骨架固体MIL-110，它在pH约为0或pH为4的条件下结晶。在p H为0时，固体(MIL-110{p H0})是唯一稳定的热力学产物，而在p H约为4时，观察到与mIL-96相竞争的动力学产物.衍射谱和Al-27核磁共振谱证明这两种情况下的骨架是相同的。对于这两种化合物来说，大孔内闭塞部分的性质和动力学看起来非常不同。MIL-1101[pH(4)]和MIL-110(PH0)都显示存在封闭的1，3，5-苯三羧酸盐(BTC)，并带有额外的硝酸盐和水分子。然而，BTC、硝酸盐和水的比例是pH的函数，导致了相同的框架和完全不同的额外框架。对于骨架外的部分，骨架经历了质子转移，这是合成pH的函数。用水洗涤MIL-110{PH0}相会产生不同的骨架外结构，水含量更高，BTC和硝酸盐含量更低。骨架的无机铝原子簇的羟基参与了质子转移，这在所有情况下都会导致阳离子骨架和阴离子外骨架。H-1-H-1DQ二维核磁共振谱(DQ=双量子)证实了骨架外BTC与Al(2，3)携带的末端水的相互作用，并表明它们接近最接近的羟基。提出了一种无衍射型外框结构作为最合理的拓扑结构。它为许多取代的MIL-110化合物的产生提供了一幅有效的图景，这些化合物将有大量的应用。
The aluminium 1,3,5-benzene tricarboxylate framework solid MIL-110, which crystallises either at pH approximate to 0 or at pH 4, has been investigated by solid-state NMR spectroscopy. At pH P,0 the solid (MIL-110{pH0}) is the unique stable thermodynamic product, whereas at pH approximate to 4 MIL-110{pH4} is observed as a kinetic product in competition with the MIL-96 phase. Diffraction studies and Al-27 NMR spectroscopy prove that the framework is identical in both cases. The nature and dynamics of occluded moieties within the large pores look quite different for the two compounds. MIL-1101{pH(4)) and MIL-110{pH0) both show the presence of occluded 1,3,5-benzene tricarboxylate (btc), with additional nitrates and water molecules. However, the proportions of btc, nitrates and water are functions of the pH, leading to an identical framework and a quite different extra-framework. With the extra-framework moieties, the framework undergoes a proton transfer which is a function of the synthesis pH. Washing the MIL-110{pH0} phase with water produces a different extra-framework structure, richer in water and poorer in btc and nitrates. The hydroxyl groups of the inorganic aluminium cluster of the framework are involved in a proton transfer, which leads for all cases to a cationic framework and an anionic extra-framework. H-1-H-1 DQ 2D NMR spectra (DQ=double quantum) give evidence for the interaction of extra-framework btc with the terminal water carried by Al(2,3) and shows their proximity to the closest hydroxyl groups. A structure for the non-diffracting extra-framework is proposed as the most plausible topology. It provides an efficient picture for the creation of many substituted MIL-110 compounds that would have a large number of applications.