Rational synthesis and functionalization of metal assemblies using a new unsymmetric bridging ligand

使用新型不对称桥连配体的金属组件的合理合成和功能化

基本信息

批准号：
11640568
负责人：
OHBA Masaaki
金额：
$ 2.3万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

In this research, hexanuclear cyclic assemblies have been prepared by a new bridging ligand having factors of structural restriction.A new unsymmetric bridging ligand 3-[1-(2-pyridyl)-3, 5-dimethylpyrazole-4-yl]-3, 5-pentane-dione (HL) was prepared. This ligand has two dissimilar metal-binding sites ('acac' and 'pypz' sites) which are forced to be perpendicular to each other due to steric hindrance of four methyl groups and the binding angle is nonlinear to form an angle of ca. 120°. Reaction of HL and CuX_2・nH_2O (X= ClO_4^-, BF_4^-) in the 1 : 1 molar ratio has given copper (II) assemblies {[Cu (L)(H_2O)] X・nH_2O}_6. These complexes have essentially same structure where the Cu (II) adopts a square-pyramidal geometry with a N_2O_2 equatorial plane formed by the 'acac' site of one ligand and the 'pypz' site of another ligand and coordination water at the axial site. And the hexanuclear cyclic structure was constructed by the six times repeat of the asymmetric unit having a cavity of di … More ameter of 17.2 Å. In the bulk, 1-D channel structure was formed by stacking of the hexagonal units. Counter anion and lattice water molecules were located between hexanuclear units, which formed an alternate arrangement of two kinds of phases. However, their packing structure was so fragile against a dehydration treatment owing to the phase structure. Although PXRD results showed that the packing arrangement was reconstructed by hydration and the hexagonal cyclic structure was maintained even after dehydration, gas adsorption ability of these complexes was not so remarkable.In order to reinforce the channel structure and to improve the gas adsorption ability, trimethoxybenzene (TMB) adduct, {[Cu (L)(H_2O)] ClO_4・4H_2O・1/3TMB}_6 was prepared. This compound maintained the original 1-D channel structure with mostly similar lattice parameters. TMB molecules were located on three-screw axis and filled the gap between hexanuclear cyclic units PXRD results showed stability against dehydration treatment, which suggests that TMB molecules sustained the packing structure as pillars. The estimation of gas adsorption ability of the TMB adduct is now in progress. Less

本研究通过具有结构限制因素的新型桥连配体制备了六核环状组装体。一种新型不对称桥连配体3-[1-(2-吡啶基)-3, 5-二甲基吡唑-4-基]-3，制备了 5-戊烷二酮 (HL)，该配体具有两个被迫结合的不同金属结合位点（“acac”和“pypz”位点）。 HL 和 CuX_2·nH_2O (X= ClO_4^-, BF_4^-) 的反应由于四个甲基的空间位阻而相互垂直，并且结合角是非线性的，形成约 120° 的角。 1摩尔比给出了铜(II)组装体{[Cu(L)(H_2O)] X・nH_2O}_6 具有基本相同的结构，其中 Cu (II) 采用方形锥体几何形状，具有由一个配体的“acac”位点和另一个配体的“pypz”位点形成的 N_2O_2 赤道面，并且六核环状结构是由具有直径为17.2 Å的空腔的不对称单元重复六次而成。大块的一维通道结构是由六方单元堆叠而成，晶格水分子位于六核单元之间，形成两种相的交替排列，但它们的堆积结构对于脱水非常脆弱。尽管PXRD结果表明，通过水合重建了堆积排列，并且即使在脱水后仍保持六方环状结构，但这些配合物的气体吸附能力并不如此。为了强化通道结构并提高气体吸附能力，制备了三甲氧基苯（TMB）加合物，{[Cu(L)(H_2O)] ClO_4·4H_2O·1/3TMB}_6，该化合物保持了原始状态。具有大部分相似晶格参数的一维通道结构 TMB 分子位于三螺杆轴上并填充了六核循环单元之间的间隙 PXRD 结果显示了稳定性。脱水处理，这表明 TMB 分子维持了堆积结构作为支柱。 TMB 加合物的气体吸附能力的估计正在进行中。