Sugar-alcohol complexes of palladium(II): on the variable rigidity of open-chain carbohydrate ligands.
Sugar-alcohol complexes of palladium(II): on the variable rigidity of open-chain carbohydrate ligands.
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钯(II)的糖醇配合物：开链碳水化合物配体的可变刚性。
DOI：
10.1002/asia.200700094
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Thomas Kunte
中科院分区：
文献类型：
--
作者：
Thorsten Allscher;Xaver Kästele;Gerhard Kettenbach;P. Klüfers;Thomas Kunte
C4、C5 和 C6 糖醇赤藓糖醇 (Eryt)、D-苏糖醇 (D-Thre)、D-阿拉伯糖醇 (D-Arab)、核糖醇 (Ribt)、木糖醇 (Xylt)、半乳糖醇 (Dulc) 和 D-甘露糖醇 (D-Mann) 在溶解于 Pd-en（Pd-en 的水溶液）中时形成螯合物。 [Pd(II)(en)(OH)2]。稳定性规则源自溶液平衡中各个物质的比例。晶体结构分析支持一系列含有糖醇作为四阴离子多元醇配体的双核化合物的 NMR 光谱结果：[Pd2(en)2(ErytH(-4))] x 10 H2O、[Pd2(en)2(D-Arab1,2;3,4H(-4))] x 7 H2O， [Pd2(en)2(Xylt1,2;3,4H(-4))] x 4 H2O、[Pd2(en)2(D-Mann1,2;3,4H(-4))] x 5 H2O 和 [Pd2(en)2(Dulc2,3;4,5H(-4))] x 6 H2O。在戊醇和己糖醇的情况下，金属化四阴离子通过分子内氢键稳定。氢键将醇盐受体均匀地连接至位于δ碳原子处的羟基供体基团。由于氢键作用，开链碳水化合物配体变得刚性。晶体结构分析提供了有关刚性配置要求的信息。根据这些规则，氢键支持的 Dulc2,3;4,5H(-4) 四阴离子提供了几何上持久的连接模式。分子内氢键似乎是多元醇金属化最具竞争力的变量。 [Pd2(tm-2,1:3,2-tet)(OH)3]OH (tm-2,1:3,2-tet = 1,3-双(2'-二甲基氨基乙基)六氢嘧啶)是一种金属化剂，即使在像卫矛醇这样棘手的情况下也可以强制完全金属化。因此，[Pd4(tm-2,1:3,2-tet)2-(DulcH(-6))]Cl2 x 16 H2O含有完全去质子化的己糖醇作为配体。
The C4, C5, and C6 sugar alcohols erythritol (Eryt), D-threitol (D-Thre), D-arabitol (D-Arab), ribitol (Ribt), xylitol (Xylt), dulcitol (Dulc), and D-mannitol (D-Mann) form chelate complexes upon dissolution in Pd-en, an aqueous solution of [Pd(II)(en)(OH)2]. Stability rules are derived from the proportion of a respective species in the solution equilibrium. Crystal-structure analysis supports the NMR spectroscopic results for a series of binuclear compounds that contain the sugar alcohols as tetraanionic polyolato ligands: [Pd2(en)2(ErytH(-4))] x 10 H2O, [Pd2(en)2(D-Arab1,2;3,4H(-4))] x 7 H2O, [Pd2(en)2(Xylt1,2;3,4H(-4))] x 4 H2O, [Pd2(en)2(D-Mann1,2;3,4H(-4))] x 5 H2O, and [Pd2(en)2(Dulc2,3;4,5H(-4))] x 6 H2O. In the case of the pentitols and hexitols, the metalated tetraanions are stabilized by intramolecular hydrogen bonds. The hydrogen bonds uniformly connect an alkoxide acceptor to the hydroxy donor group located at the delta carbon atom. As a consequence of hydrogen bonding, the open-chain carbohydrate ligands become rigid. Crystal-structure analysis provides information on the configurational requirements for rigidity. According to these rules, the hydrogen-bond-supported Dulc2,3;4,5H(-4) tetraanion provides a geometrically persistent ligating pattern. Intramolecular hydrogen bonding seems to be the most-competitive variable to metalation of a polyol. [Pd2(tm-2,1:3,2-tet)(OH)3]OH (tm-2,1:3,2-tet = 1,3-bis(2'-dimethylaminoethyl)hexahydropyrimidine) is a metallizing agent that can force full metalation even in a case as intractable as that of dulcitol. Accordingly, [Pd4(tm-2,1:3,2-tet)2-(DulcH(-6))]Cl2 x 16 H2O contains the fully deprotonated hexitol as the ligand.