大型多面体协调的结构和动态行为:一种不寻常的到之间的相互转换
Andrew Stephenson1, Stephen P Argent, Thomas Riis-Johannessen
1Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom.
Journal of the American Chemical Society
|December 24, 2010
概括
由双双酸桥接联体 (L) 与过渡金属形成的新协调展示了新的结构. (Cd) 三角 prismatic 子是溶液中稳定的热力学产物,在几个星期内从一个更大的子中形成.
科学领域:
- 协调化学 协调化学
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
背景情况:
- 使用桥接连体合成多面体协调是超分子化学的一个关键领域.
- 连接体L,{α,α-bis[3-(2-pyridyl) pyrazol-1-yl]-1,4-dimethylbenzene},含有两个化型pyrazolyl-pyridine单元,使复杂结构的形成成为可能.
- 之前的研究已经表明,八核立方体与Ni的形成.
研究的目的:
- 探索双双酸桥接联体L与各种过渡金属 (Cu(II), Zn(II), Cd(II)) 的反应.
- 描述由此产生的协调,重点关注新型结构类型.
- 研究这些协调的溶液稳定性和形成路径.
主要方法:
- 过渡金属二 (Cu(II), Zn(II), Cd(II)) 与联体L在2M:3L的比率中的反应.
- 使用X射线晶体学对得到的协调的结构性表征.
- 使用电子喷射质谱法 (ES-MS) 和1H NMR光谱法分析溶液行为.
主要成果:
- (II) 复合物形成了一个八核立方体,与之前的发现相一致.
- 新的三角形镜 [Cu(6) L(9) ](BF(4)) ((12) 用Cu(II) 形成.
- 对于Zn (II) 和Cd (II) 来说,观察到前所未有的六角核子[M(16) L(24) ]X(32) 与一个斜四角形截断四面体核心.
- 六核三角镜[Cd(6) L(9) ][BF(4)) [12]被确定为溶液中的Cd(II) 的热力学产物,由几周内[Cd(16) L(24) ]子的重新排列形成.
结论:
- 双双酸桥接联体L可以组装成不同的多面体协调,具有不同的过渡金属.
- 三角体体是溶液中Cd(II) 的热力学优势产物,尽管最初形成了一个更大的六十核体.
- 这项研究强调了协调形成和溶液中重新排列的动态性质.
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