The aryl-substituted α-diimine (DI) nickel vinyl complex (^iPrDI)Ni(CH═CH₂) (^iPrDI = [2,6-(ⁱPr)₂C₆H₃N═C(CH₃)]₂) was synthesized and structurally characterized. The complex is dimeric in the solid state and has a distorted-square-planar geometry at nickel. A combination of single-crystal X-ray diffraction, EPR, magnetic susceptibility, and NMR analyses was used to elucidate the electronic structure of the compound, and it is best described as a low-spin Ni(II) derivative with a singly reduced α-diimine chelate. Addition of CO₂ to the nickel vinyl complex resulted in insertion into the nickel–carbon bond to yield the corresponding nickel acrylate (^iPrDI)Ni(κ²-O₂CCH═CH₂). EPR spectroscopy coupled with DFT calculations established that the S = 1/2 product maintains the nickel(II) oxidation state with an α-diimine-centered radical. Addition of acrylic acid to (^iPrDI)Ni(CH═CH₂) induced rapid, net bimetallic reductive elimination to release butadiene and produced the metastable olefin-bound acrylic acid complex (^iPrDI)Ni(η²-CH₂═CHCO₂H). Over the course of 2 h at 23 °C, this complex underwent a net oxidation to produce (^iPrDI)Ni(κ²-O₂CCH═CH₂), with concomitant loss of H₂.

中文翻译：

---

与丙烯酸合成有关的还原α-二胺镍配合物的合成及反应活性

的芳基取代的α二亚胺（DI）镍乙烯基配合物（^的iPr DI）的Ni（CH = CH ₂）（^的iPr DI = [2,6-（^我PR）₂ C ^ ₆ ħ ₃ N = C（CH ₃）] ₂）被合成并在结构上表征。该络合物在固态是二聚体，并且在镍处具有扭曲的正方形平面几何形状。X射线单晶衍射，EPR，磁化率和NMR分析的结合被用来阐明化合物的电子结构，最好将其描述为α单独还原的低自旋Ni（II）衍生物-二亚胺螯合物。添加CO ₂到镍乙烯基复杂导致插入镍-碳键，得到相应的镍丙烯酸酯（^的iPr DI）的Ni（κ ² -O ₂ CCH═CH ₂）。EPR光谱与DFT计算相结合，确定S = 1/2乘积以α-二亚胺为中心的自由基保持了镍（II）的氧化态。丙烯酸的除（^的iPr DI）的Ni（CH = CH ₂）诱导快速，净双金属还原消除，以释放丁二烯和产生的亚稳烯烃结合的丙烯酸复合物（^的iPr DI）的Ni（η ² -CH ₂ ═CHCO ₂H）。经2小时在23℃下，这种复杂的进行了净氧化过程中，以产生（^的iPr DI）的Ni（κ ² -O ₂ CCH═CH ₂），的H同时损失₂。