Unusual Stepwise Assembly and Molecular Growth: [H14Mo37O112]14− and [H3Mo57V6(NO)6O189(H2O)12(MoO)6]21−
Unusual Stepwise Assembly and Molecular Growth: [H14Mo37O112]14− and [H3Mo57V6(NO)6O189(H2O)12(MoO)6]21−
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DOI：
10.1002/(sici)1521-3765(19980615)4:6
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发表时间：
1998-06
期刊：
影响因子：
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通讯作者：
A. Müller;Jochen Meyer;E. Krickemeyer;C. Beugholt;H. Bögge;F. Peters;M. Schmidtmann;P. Kögerler-
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文献类型：
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作者：
A. Müller;Jochen Meyer;E. Krickemeyer;C. Beugholt;H. Bögge;F. Peters;M. Schmidtmann;P. Kögerler-
从简单的构建块通过保守的自组装过程形成复杂分子系统的理解仍然是一个挑战。我们报道了大还原多金属氧酸盐化合物（NH4）（14）[H14Mo37O112]的合成和结构表征。35水(1),(NH4) (21) [H3Mo57V6 (NO) (6) o - 183 (H2O)(18)]。55H(2)O(2)（经改进合成）和Na-3(NH4)(18)[H3Mo63V6(NO)(6)O-195(H2O)(12)]。41 h (2) O(3)。星团系统是由一个逐步增长的过程形成的。这意味着在团簇形成过程中，出现了短暂的多金属氧酸中间体（其中一些我们能够分离出来）。中间簇片段的负电荷和亲核性在它们被还原时增加，导致亲电试剂的进一步吸引，从而促进分子体系的生长。在簇阴离子3的情况下，我们观察到，相应地，在空气氧化中损失了[MoO]（4+）金属氧酸盐碎片；这意味着它的吸收和释放是由簇的还原程度控制的。相应地，{Mo57+xV6}型阴离子2和3之间的中间体可以分离出来。不寻常的阴离子1是通过对称破缺处理形成的。
The understanding of the formation of complex molecular systems from simple building blocks by conservative self-assembly processes is still a challenge. We report the synthesis and structural characterization of the large reduced polyoxometallate compounds (NH4)(14)[H14Mo37O112]. 35 H2O (1), (NH4)(21)[H3Mo57V6(NO)(6)O-183(H2O)(18)]. 55H(2)O (2) (by an improved synthesis) and Na-3(NH4)(18)[H3Mo63V6(NO)(6)O-195(H2O)(12)]. 41H(2)O (3). The cluster systems are formed by a stepwise growth process. This implies the appearance, during the cluster formation, of ephemeral polyoxometallate intermediates (some of which we were able to isolate). The negative charge and therefore the nucleophilicity of the intermediate cluster fragments increase when they are reduced, resulting in further attraction of electrophiles and thus in growth of molecular systems. IN the case of the cluster anion of 3 we observed, correspondingly, the loss of an [MoO](4+) oxometallate fragment by air oxidation; this implies that aits uptake and release are controlled by th degree of reduction of the cluster. correspondingly, intermediates between the anions of 2 and 3 of the {Mo57+xV6} type could be isolated. The unusual anion of 1 is formed by symmetry breaking processed.