咪唑醛与2-苯基嘧啶的二肼基衍生物的反应提供了双(酰基hydr)配体家族,它们与包括Fe(II),Co(II),Cu(II)和Zn在内的过渡金属离子形成[2×2]金属对位络合物(二)。游离的配体在供体和受体上都表现出氢键相互作用,主要涉及咪唑单元,而金属离子的结合占据了所有的受体位点,只留下了吡咯-NH位点作为氢键供体,尽管它通过强大的基础可以使受体再生。这些H键相互作用已通过1 H NMR光谱在溶液中和固态下通过几种晶体结构测定方法进行了研究。铁(II)网格似乎是溶液中很宽温度范围内的唯一高自旋物种。在固态状态下,可以观察到在1.8 K和300 K之间有各种形式的自旋交联行为,这在晶态下可能发生的氢键变化形式方面是合理的。
Self-ordering of metallogrid complexes via directed hydrogen-bonding
作者:Artur R. Stefankiewicz、Guillaume Rogez、Jack Harrowfield、Alexandre N. Sobolev、Augustin Madalan、Juhani Huuskonen、Kari Rissanen、Jean-Marie Lehn
DOI:10.1039/c2dt31384g
日期:——
deprotonation by a strong base can regenerate an acceptor. These H-bonding interactions have been studied by 1H NMR spectroscopy in solution and in the solidstate by means of several crystal structure determinations. The Fe(II) grids appear to be exclusively high-spin species over a wide temperature range in solution. In the solidstate various forms of spin-crossover behaviour can be observed between 1
咪唑醛与2-苯基嘧啶的二肼基衍生物的反应提供了双(酰基hydr)配体家族,它们与包括Fe(II),Co(II),Cu(II)和Zn在内的过渡金属离子形成[2×2]金属对位络合物(二)。游离的配体在供体和受体上都表现出氢键相互作用,主要涉及咪唑单元,而金属离子的结合占据了所有的受体位点,只留下了吡咯-NH位点作为氢键供体,尽管它通过强大的基础可以使受体再生。这些H键相互作用已通过1 H NMR光谱在溶液中和固态下通过几种晶体结构测定方法进行了研究。铁(II)网格似乎是溶液中很宽温度范围内的唯一高自旋物种。在固态状态下,可以观察到在1.8 K和300 K之间有各种形式的自旋交联行为,这在晶态下可能发生的氢键变化形式方面是合理的。
Self‐Assembly, Structure and Solution Dynamics of Tetranuclear Zn
<sup>2+</sup>
Hydrazone [2×2] Grid‐Type Complexes
作者:Mihail Barboiu、Mario Ruben、Georges Blasen、Nathalie Kyritsakas、Elizabeth Chacko、Manisha Dutta、Olga Radekovich、Kimberly Lenton、David J. R. Brook、Jean‐Marie Lehn
DOI:10.1002/ejic.200500963
日期:2006.2
π–π stacking between the phenyl ring and the hydrazone units of the perpendicular ligands in the complexes induces a perfect orthogonal arrangement suitable for applications in self-organized metallosupramolecular systems. Zinc complexes provide an opportunity to study the acid–base chemistry without the added effects due to paramagnetism or redox chemistry. The intermediate protonated grids undergo
作者:Artur R. Stefankiewicz、Jack Harrowfield、Augustin M. Madalan、Jean-Marie Lehn
DOI:10.1039/c3ce41510d
日期:——
New [2 × 2] metallogrids derived from a ditopic ligand with terminal salicylaldimine binding sites giving six-membered chelate rings have been structurally characterised in order to determine the effect of ring size variation on the planarity of the core M4 unit. Both the Zn4 unit of the grid formed from the neutral ligand and the Fe4 unit of the grid formed from the doubly deprotonated ligand are very close to planar, despite considerable differences in the coordination spheres of the two metal ions and the difference in their oxidation states (Zn(II), Fe(III)).
These molecular strands are shown to adopt helical conformations of 1.5 and 2.5 turns, respectively. The helical shape of 1 has been confirmed and structurally characterized by X-ray crystallography. The results indicate that the pyrimidine-hydrazone unit is a satisfatory helicity codon, so that the facile hydrazone formation provides an efficient procedure for generating helical structures. This