A N-heterocyclic carbene (NHC) ligand, L₁ bearing a pendant phosphonate ester group is used to prepare two new NHC-Pd(II) complexes, [Pd(L₁)₂I₂] (1) and [Pd(L₁)(py)I₂] (2) (py = pyridine). Hydrolysis of phosphonate ester group in 2 results another Pd(II)-NHC complex, [Pd(L₂)(py)I₂] (3) where a phosphonic acid group is attached to the NHC ligand L₂. All the three complexes are characterized by analytical and spectroscopic studies while the molecular structures of 1-2 are also determined by single crystal X-ray diffraction measurement. The catalytic efficacies of 1-3 in Suzuki-Miyaura cross coupling reactions of aryl halides and aryl boronic acid are investigated. DFT calculations were performed to decipher the role phosphonate ester or phosphonic acid substituents on the catalytic efficacy.

N-杂环卡宾 (NHC) 配体 L ₁带有膦酸酯侧基，用于制备两种新的 NHC-Pd(II) 配合物 [Pd(L ₁ ) ₂ I ₂ ] ( 1)和 [Pd(L) ₁ )(py)I ₂ ] ( 2 ) (py = 吡啶)。2中膦酸酯基团的水解产生另一个 Pd(II)-NHC 复合物，[Pd(L ₂ )(py)I ₂ ] ( 3 )，其中膦酸基团与 NHC 配体 L ₂相连。所有三种配合物均通过分析和光谱研究表征，而1 - 2的分子结构也可通过单晶 X 射线衍射测量来确定。研究了1-3在芳基卤化物和芳基硼​​酸的Suzuki-Miyaura交叉偶联反应中的催化作用。进行 DFT 计算以破译膦酸酯或膦酸取代基对催化功效的作用。