Characterization of a 1:1 Cu-O2 adduct supported by an anilido imine ligand
Characterization of a 1:1 Cu-O2 adduct supported by an anilido imine ligand
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DOI：
10.1021/ic050280p
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发表时间：
2005-10-03
影响因子：
4.6
通讯作者：
Tolman, WB
中科院分区：
文献类型：
--
作者：
Reynolds, AM;Gherman, BF;Tolman, WB
合成了邻苯酰亚胺配体邻苯酰亚胺与铜（I）的空间位阻配合物o-C6 H4 {N（（C6 H3 Pr 2）-Pr-i）}{C（R）=（NC 6 H3 Pr 2）-Pr-i}（-）（L-1，R = H; L-2，R = CH 3），并通过光谱和X-射线晶体学方法对其进行了表征.这些配合物与O-2具有高度反应性，并且在L-2的情况下，低温氧化的产物通过光谱、X射线晶体学和计算方法进行了充分表征。共振拉曼光谱在974 cm（-1）处具有同位素敏感的振动（Delta（O-18）= 66 cm（-1）），与O-O伸缩的归属一致。尽管支持苯胺基亚胺配体提供了不对称的配位环境，但X射线晶体结构证实O-2部分与铜中心的侧边结合相当对称，并且1.392（2）埃的O-O键长表明该中间体具有显著的Cu（III）-过氧特征。理论计算支持这一解释，并预测，虽然可以获得完全优化的末端单重态几何形状，但在CASPT 2/TZP水平下，它的能量比侧边异构体高3.5 kcal mol（-1）。
Copper(l) complexes of sterically hindered anilido imine ligands o-C6H4{N((C6H3Pr2)-Pr-i)}{C(R)=(NC6H3Pr2)-Pr-i}(-) (L-1, R = H; L-2, R = CH3) have been prepared and characterized by spectroscopic and X-ray crystallographic methods. These complexes are highly reactive with O-2, and in the case of L-2 the product of low-temperature oxygenation was fully characterized by spectroscopic, X-ray crystallographic, and computational methods. The resonance Raman spectrum features an isotope-sensitive vibration at 974 cm(-1) (Delta(O-18) = 66 cm(-1)), consistent with assignment as an O-O stretch. Despite the asymmetric coordination environment provided by the supporting anilido imine ligand, the X-ray crystal structure confirms rather symmetric side-on binding of the O-2 moiety to the copper center, and the O-O bond length of 1.392(2) angstrom indicates that this intermediate has significant Cu(lll)-peroxo character. Theoretical calculations support this interpretation and predict that while a fully optimized end-on singlet geometry can be obtained, it is higher in energy than the side-on isomer by 3.5 kcal mol(-1) at the CASPT2/TZP level.