substituent effects. This confirms that the properties of the Cu(I) complexes are usually more influenced by steric effects than by the inductive effects of substituents of the ligands. In fact, the results obtained showed the importance of non-covalent intermolecular interactions in the structuring of the coordination geometry around the Cu centre and in the coordinative stability to avoid dissociative
一系列具有 ([Cu( N -4- R }pyridine-2-yl-methanimine)(PPh 3 )Br])配方的六种新 Cu( I ) 配合物,其中R对应于供体或受体对位取代基,已被合成并用于研究自缔合对其结构和电
化学性质的影响。X射线衍射结果表明,在所有配合物中,填料都是由超分子π堆积和氢键形成的二聚体组织而成的。1个几种浓度的 H-NMR 实验表明,所有复合物在溶液中都经历快速自缔合单体-二聚体平衡,而
亚胺配体特定质子中共振频率向高场或低场的变化允许确定二聚体具有相似的结构那些在
水晶中发现的。该自缔合过程的热力学参数是根据二聚化常数计算的,二聚化常数通过 VT- 1 H-NMR 实验针对不同温度下的几种浓度确定。K D值(4.0 至 70.0 M -1范围)、Δ H(-1.4 至 -2.6 kcal mol -1范围)、Δ S(-0.2 至 2.1 cal mol -1 K