Burton Allen W
Chevron Energy Technology Company, Richmond, California 94802, USA.
J Am Chem Soc. 2007 Jun 20;129(24):7627-37. doi: 10.1021/ja070303u. Epub 2007 May 25.
This study first uses molecular modeling to examine the structure-directing effects of small amines that are selective for the crystallization of MTT-type zeolite phases. The optimized van der Waals interactions of these small amines are compared within the one-dimensional pore zeolites with the MTT, TON, and MTW frameworks. From these results and our previous molecular modeling studies of structure-directing agents (SDA) for MTT-type zeolites, a large number of amines or quaternary ammonium molecules are successfully predicted to be selective for MTT phases. These molecules were chosen by matching the crystallographic periodicity of the pore structure with the distances between the centers of branched groups in these molecules. These molecules vary in length and in the number of branched moieties, and a few of these molecules are polymeric or oligomeric. In test cases where the distances between the branched groups are not multiples of the pore periodicity, with few exceptions these molecules usually do not produce MTT phases. Finally, we discuss the inorganic conditions necessary for crystallization of MTT phases in borosilicate preparations with some of the diamines in this investigation.
本研究首次使用分子模拟来研究对MTT型沸石相结晶具有选择性的小胺的结构导向作用。在具有MTT、TON和MTW骨架的一维孔沸石中，比较了这些小胺的优化范德华相互作用。根据这些结果以及我们之前对MTT型沸石结构导向剂（SDA）的分子模拟研究，成功预测了大量胺或季铵分子对MTT相具有选择性。这些分子是通过将孔结构的晶体学周期性与这些分子中支链基团中心之间的距离相匹配而选择的。这些分子的长度和支链部分的数量各不相同，其中一些分子是聚合物或低聚物。在支链基团之间的距离不是孔周期性倍数的测试案例中，除了少数例外，这些分子通常不会产生MTT相。最后，我们讨论了在本研究中使用一些二胺的硼硅酸盐制剂中MTT相结晶所需的无机条件。
