Four half-sandwich Ru(II) complexes (1)–(4) with the general formulae [Ru(η⁶-p-cymene)(L)Cl₂] were synthesized by the reaction of one equivalent of the Ru(II) p-cymene dimer with two equivalents of a p-substituted aniline derivative L (where L is p-methyl, p-isopropyl, p-methoxy, or p-hydroxy aniline). The structures of complexes (2)–(4) were determined by single-crystal X-ray diffraction studies. The structural analysis revealed piano-stool geometry at the Ru(II) ions which are coordinated to the η⁶-p-cymene, two chloride anions and the amine group of the aniline ligand. In the structure of (2)–(4), the coordinated chloride ions make intermolecular hydrogen bonding with the –NH₂ group of an adjacent molecules (NH–Cl) resulting in hydrogen bond networks. The catalytic activities of the complexes in transfer hydrogenation of acetophenone were studied. Complex [Ru(η⁶-p-cymene)(p-methylaniline)Cl₂] (1) showed the best catalytic performance in the transfer hydrogenation of acetophenone. The presence and positions of methyl and bromide groups on the acetophenone have an impact on the catalytic activity in transfer hydrogenation properties of the complex (1). Moreover, catalytic activity of the complex (1) is significantly higher in the transfers hydrogenation of cyclohexanone than 2-hexanone.

四个半夹心的Ru（II）配合物（1） - （4）与通式[茹（η ⁶ - p -cymene）（L）氯₂ ]是由一当量的Ru（II）的反应合成的具有两个当量的对位取代苯胺衍生物L（其中L为对甲基，对异丙基，对甲氧基或对羟基苯胺）的对苯二酚二聚体。配合物（2）–（4）的结构是通过单晶X射线衍射研究确定的。结构分析显示钢琴凳几何在被配位到钌（II）离子η ⁶ - p-Cymene，两个氯阴离子和苯胺配体的胺基。在（2）–（4）的结构中，配位的氯离子与相邻分子的–NH ₂基团（NH–Cl）形成分子间氢键，从而形成氢键网络。研究了配合物在苯乙酮转移加氢中的催化活性。复杂的[Ru（η ⁶ - p -cymene）（p甲基苯胺）氯₂]（1）在苯乙酮的转移加氢中表现出最好的催化性能。苯乙酮上甲基和溴化物基团的存在和位置会影响配合物（1）的转移加氢性能中的催化活性。此外，在环己酮的转移氢化中，配合物（1）的催化活性明显高于2-己酮。