镍催化体系合成顺式聚丁二烯的研究——Ⅶ.紫外可见光谱法探讨镍系各组分间的相互作用

环烷酸镍的汽油或甲苯溶液呈亮绿色,根据自旋允许d-d跃迁,在光谱的红和兰区有三个吸收带,其峰值分别是403、680和1170nm,络合物具有八面体构型。在Ni-Al体系中,当Al/Ni摩尔比<0.53,只发生配位体的交换反应,Al/Ni≥0.53,体系中发生还原反应,Ni(II)→Ni(I)→Ni(O)。在Ni-B体系中,只发生配位体交换反应,生成的氟-硼-镍络合物具有和环烷酸镍相类似的d-d吸收带,络合物也具有八面体构型。以上结论与磁化率法的结果一致。

SYNTHESIS OF CIS-1, 4-POLYBUTADIENE WITH NICKEL CATALYST——Ⅶ. Utraviolet and Visible Spectra Study of Interactions Between Components in Nickel Catalystic System

Ni(II) naphthenate in gasoline or toluene shows a light green color, which is the result of absorption in the red and blue parts of the spectrum, the three bands due to the spin-allowed d-d transitions are 403, 680, and 1170 nm respectively. Ni(II) complex is octahedral complex. The naphthenate ligand attached to Ni(II) can be exchanged for an alkyl group on isobutyla-luminium if Al/Ni in the mixture containing metalalkyl and naphthenate does not exceed the value of 0.53. At higher ratio (Al/Ni≥0.53) Ni(II) is reduced to Ni(I) and (Ni(0). In the mixture of Ni(II) with BF3.OEt2 the naphthenate ligand is exchanged for halogen. The reaction produces Ni(II) complex, which is traced to the presence of three weak d-d bands and it is found to be octahedral complex as well as Ni(naph)2. The conclusions are analogous to the discussion on the basis of the measuring of magnetic susceptibility of the same nickel cata-lystic system.