Chromium complexes of general formula [Cr{ZNO}(THF)Cl₂] [2a, ZNO = C₉H₆N-8-(N=CH)-2,4-tert-butyl-2-(OC₆H₂); 2b, ZNO = Ph(NH)-C₂H₄-(N=CH)-2,4-tert-butyl-2-(OC₆H₂); 2c, ZNO = 2-MeO-Ph-CH₂-(N=CH)-2,4-tert-butyl-2-(OC₆H₂); 2d, ZNO = 2-PhO-Ph-(N=CH)-2,4-tert-butyl-2-(OC₆H₂); 2e, ZNO = PhO-C₂H₄-(N=CH)-2,4-tert-butyl-2-(OC₆H₂)] and the bis(ligand) complex [Cr{C₉H₆N-8-NH₂}₂Cl₂]Cl (4) were synthetized and characterized by elemental analysis, IR spectroscopy, and by X-ray crystallography for 4. In the solid state, 4 is monomeric with two 8-amino-quinoline acting as bidentate ligands and two chloride ligands in cis position. The DFT calculations showed slightly higher HOMO energy for 2d. In addition, the energy levels of the LUMO are slightly influenced by pendant O- and N-donor group. Particularly, the LUMOs for complexes 2a and 2d show a small contribution from Cr and Cl atoms as compared to other chromium complexes (2b, 2c and 2e), and the orbitals are almost entirely delocalized over the phenoxy-imine unit. Upon activation with methylaluminoxane (MAO), chromium precatalysts 2a-2e showed good activity in ethylene oligomerization (TOF = 22.0 – 52.7 × 10³ (mol ethylene)(mol Cr)⁻¹⋅h⁻¹ at 80°C) with Schultz-Flory distribution of oligomers (K_C4-C10 ≈ 0.92), and production of polymer varying from 2.9 to 22.3 wt.%. The catalytic performance is mainly controlled by electronic effects at the phenoxy-imine ligands. The bis(ligand) chromium complex 4 showed good activity in ethylene oligomerization (TOF = 39,400 (mol ethylene)(mol Cr)⁻¹ h⁻¹), producing mostly oligomers (95.2 wt% of total products) with high selectivity for α-olefins. The highest activity among the six precatalysts screened was reached with 2c (TOF = 52,700 mol(ethylene)•mol(Cr)⁻¹•h⁻¹).

通式为[Cr {ZNO}（THF）Cl _2的铬配合物] [ 2a，ZNO = C ₉ H ₆ N-8-（N = CH）-2,4-叔丁基-2-（OC ₆ H ₂）; 2b， ZNO ＝ Ph（NH）-C ₂ H _4-（N ＝ CH）-2，4-叔丁基-2-（OC ₆ H ₂ ）；2c，ZNO ＝ 2-MeO-Ph-CH _2-（N ＝ CH）-2，4-叔丁基-2-（OC ₆ H ₂）；2d，ZNO ＝ 2-PhO-Ph-（N ＝ CH）-2，4-叔丁基-2-（OC ₆ H ₂）；2e，ZNO = PhO-C ₂ H ₄-（N = CH）-2,4-叔丁基-2-（OC ₆ H ₂）]和双（配体）络合物[Cr {C ₉ H ₆ N-8-NH ₂ } ₂ Cl ₂ ] Cl （4）进行了synthetized和表征通过元素分析，红外光谱，并且通过X射线晶体为4。在固态下，4是单体，其中两个8-氨基-喹啉用作双齿配体，两个氯配体在顺式位置。DFT计算显示2d的HOMO能量略高。此外，LUMO的能级还受O和N侧基的影响。特别是用于复合物的LUMO与其他铬配合物（2b，2c和2e）相比，图2a和2d显示出Cr和Cl原子的贡献很小，并且轨道几乎完全在苯氧基亚胺单元上离域。当用甲基铝氧烷（MAO），铬预催化剂活化2A -图2e显示了良好的活性在乙烯低聚（TOF = 22.0 - 52.7×10 ³（摩尔乙烯）（摩尔铬）^-1 ⋅h ^-1在80℃下）与Schultz-低聚物的弗洛里分布（K _C4-C10≈0.92），且聚合物的产量在2.9至22.3 wt。％之间变化。催化性能主要受苯氧基-亚胺配体的电子效应控制。双（配体）铬配合物4表现出良好的活性在乙烯低聚（TOF = 39400（摩尔乙烯）（摩尔铬）^-1 ħ ^-1），产生主要是低聚物（产品总数的95.2％（重量））与α-高选择性烯烃。筛选出的六种预催化剂中的最高活性达到2c（TOF = 52,700 mol（乙烯）·mol（Cr）^-1 •h ^-1）。