Chromium complexes supported by bidentate thioether-imine [N,S] ligands: synthesis and ethylene oligomerization studies
作者:J. L. S. Milani、A. F. P. Biajoli、F. I. Batista、R. S. Oliboni、O. L. Casagrande
DOI:10.1039/d0nj04642f
日期:——
A series of new Cr(III) complexes of general formula [CrN,S}(THF)Cl3] (2a, N,S = PhS-2-PhCH = N-tBu; 2b, N,S = PhS-2-PhCH = N-C6H4-4-OMe; 2c, N,S = PhS-2-PhCH = N-C6H5; 2d, N,S = tBuS-2-PhCH = N-C6H5) were prepared and characterized by elemental analysis, IR spectroscopy and ESI-HRMS. DFT calculations confirm that the mer isomers are more stable by 23.9–34.3 kcal mol−1 than the fac isomers. Upon activation
一系列新的通式[Cr N,S}(THF)Cl 3 ]的Cr(III)配合物(2a,N,S = PhS-2-PhCH = N- t Bu; 2b,N,S = PhS -2-PhCH = NC 6 H 4 -4-OMe; 2c,N,S = PhS-2-PhCH = NC 6 H 5 ; 2d,N,S = t BuS-2-PhCH = NC 6 H 5)通过元素分析,红外光谱和ESI-HRMS制备并表征。DFT计算证实,mer异构体比fac稳定23.9–34.3 kcal mol -1异构体。用甲基铝氧烷(MAO)活化后,铬预催化剂2a–2d在Schultz–乙烯的低聚反应中表现出中等活性(TOF = 3.4–26.6×10 3(mol乙烯)(mol Cr)-1 h -1在80°C)。低聚物的弗洛里分布(K C4– C12≈0.90)和聚合物的产量在1.2至9.8 wt%之间变化。催化活性主要