作者:Qian Zhang、Lisi He、Jun-Min Liu、Wei Wang、Jianyong Zhang、Cheng-Yong Su
DOI:10.1039/c0dt00406e
日期:——
M2L2 type metallacyclic complexes, [Pd2(L1)2Cl4]·1.5CH2Cl2 (1), [Pd2(L1)2Cl4]·2CHCl3 (2), [Pd2(L2)2Cl4]·2CH2Cl2·2CH3CN (3), [Pd2(L2)2Cl4]·2CHCl3·2CH3CN (4) and [Pd2(L3)2Cl4]·CH2Cl2·2CH3CN (5), have been prepared from three semi-rigid benzimidazol or benzotriazol ligands, 1,4-bis(benzimidazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene (L1), 1,4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene (L2) and 1,4-bis(benzotriazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene (L3). All the complexes were structurally characterized by single-crystal X-ray diffraction and the phase purity was confirmed by powder X-ray diffraction (PXRD) measurements. The solution structure of representative complex 1 was studied by 1H NMR titration and ESI mass spectroscopy. The thermal stability and guest-exchange properties of 1, 3 and 4 were investigated, revealing that the Pd2L2 metallacycles can act as a selective receptor for CH2Cl2 or CHCl3 guest molecules. The catalytic activity of 1 in Suzuki–Miyaura coupling reaction was also studied and 1 could be recycled at least 5 times under heterogeneous conditions, indicative of a potential self-supported catalyst.
M2L2型金属环状络合物[ أحدث ]
[Pd2(L1)2Cl4]·1.5CH2Cl2 (1), [Pd2(L1)2Cl4]·2CHCl3 (2), [Pd2(L2)2Cl4]·2CH2Cl2·2CH3CN (3), [Pd2(L2)2Cl4]·2CHCl3·2CH3CN (4)和[Pd2(L3)2Cl4]·CH2Cl2·2CH3CN (5)是由三种半刚性苯并咪唑或苯并三唑配体制备而成的,这些配体分别是1,4-双(苯并咪唑-1-基甲基)-2,3,5,6-四甲基苯(L1),1,4-双(5,6-二甲基苯并咪唑-1-基甲基)-2,3,5,6-四甲基苯(L2)和1,4-双(苯并三唑-1-基甲基)-2,3,5,6-四甲基苯(L3)。所有络合物通过单晶X射线衍射进行结构表征,并通过粉末X射线衍射(PXRD)测量确认了相纯度。代表性络合物1的溶液结构通过1H NMR滴定法和ESI质谱进行研究。对1、3和4的热稳定性和客体交换性质进行了研究,结果显示Pd2L2金属环可以作为选择性受体,选择性接纳CH2Cl2或CHCl3客体分子。还研究了1在铃木-宫浦偶联反应中的催化活性,结果表明在非均相条件下,1至少可以循环使用5次,显示出其作为潜在自支撑催化剂的能力。