New Binding Modes of 1‐Acetyl‐ and 1‐Benzoyl‐5‐hydroxypyrazolines – Synthesis and Characterization of
<i>O,O′</i>
‐Pyrazoline‐ and
<i>N</i>
,
<i>O</i>
‐Pyrazoline‐Zinc Complexes
作者:Chika I. Someya、Shigeyoshi Inoue、Elisabeth Irran、Sebastian Krackl、Stephan Enthaler
DOI:10.1002/ejic.201100248
日期:2011.6
side product. Characterization of complexes 8a and 8c by X-ray crystallography revealed a dimeric structure in the solid state. The two subunits generate a Zn2O2 square. The acetyl and benzoyl functionality of the ligands coordinate to the metal to span a six-membered ring. Moreover, the coordination mode of the ligand can be easily influenced by the addition of base. Here, N,N,N′,N′-tetramethylethylenediamine
1-乙酰基-和 1-苯甲酰基-5-羟基吡唑啉 1a [3,5-CF3, 1-C(=O)CH3], 1b [3,5-CH3, 1-C(=O)CH3] 和 1c [3,5-CF3, 1-C(=O)C6H5] 已以良好的产率合成,并通过 X 射线晶体学表征。1-乙酰基-和1-苯甲酰基-5-羟基吡唑啉配体用二甲基锌以1:1的摩尔比处理,形成具有RO-Zn-Me基序的配合物8。这些配合物可通过简单的布朗斯台德酸碱反应生成甲烷作为副产物。通过 X 射线晶体学表征复合物 8a 和 8c 揭示了固态的二聚体结构。这两个亚基生成一个 Zn2O2 方块。配体的乙酰基和苯甲酰基官能团与金属配位以跨越六元环。此外,配体的配位模式很容易受到碱添加的影响。这里,N,N,N',应用 N'-四甲基乙二胺 (tmeda) 去除配体 4 位的酸质子并裂解半氨基官能团。tmeda-H+将质子转移到与锌相连的甲基上,促进甲烷的去除;游离的