The Impact of Group‐10 Metals on the Solvent‐induced Disproportionation of o‐Semiquinonato Complexes
The Impact of Group‐10 Metals on the Solvent‐induced Disproportionation of o‐Semiquinonato Complexes
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第 10 族金属对邻半醌配合物溶剂诱导歧化的影响
DOI：
10.1002/chem.201900172
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Shota Yamada Takeshi Matsumoto Ho-Chol Chang
中科院分区：
文献类型：
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作者：
Higuchi Junichi;Kuriyama Shogo;Eizawa Aya;Arashiba Kazuya;Nakajima Kazunari;Nishibayashi Yoshiaki;Shota Yamada Takeshi Matsumoto Ho-Chol Chang
氧化[MII(3，5-DTBCat)(DTBbpy)](M=Ni([Ni])，Pd([Pd])和Pt([Pt])；3，5-DTBCat=3，5-二叔丁基儿茶酚；DTBbpy=4，4‘-二叔丁基-2，2’-联吡啶)得到二聚体{[NiII(3，5‐DTBSQ)(DTBbpy)](PF6)}2({[Ni](PF6)}2；3，5-DTBSQ=3，5-二叔丁基半喹酮)和单体半喹(SQ)配合物[MII(3，5-DTBSQ)(DTBbpy)](PF6)(M=Pd([Pd](PF6))和Pt([PT](PF6)。SQ络合物的负溶剂变色性质使我们能够估计它们的偶极moments：[Pd](PF6)>；[Pt](PF6)>；{[Ni](PF6)}2.的相对顺序。络合物[Pd](Pf_6)和[PT](Pf_6)在CH2Cl2和甲苯中呈单体结构，而在极性溶剂如四氢呋喃、甲醇、乙醇、二甲基甲酰胺或二甲基亚砜中，它们在室温下逐渐歧化成[M]和3，5-二叔丁基对苯二酚。光谱研究结果表明，氧化镍络合物在CH2Cl2中为单体结构([Ni](PF6))，而在其他溶剂中为二聚结构({[Ni](PF6)}2)。在极性溶剂中，在323 K时，{[Ni](Pf6)}2可能与[Ni]和3，5-DTBBQ不成比例，因此在温度上表现出明显的溶剂和金属依赖性。[Ni](PF6)}2和[M](PF6)对歧化的相对活性与在CH2Cl2和DMF中电化学估算的K值有关。目前的工作表明，溶剂的极性和SQ络合物的偶极矩促进歧化，这可以通过合理选择金属离子、溶剂和温度来控制。
The oxidation of [MII(3,5‐DTBCat)(DTBbpy)] (M=Ni ([Ni]), Pd ([Pd]), and Pt ([Pt]); 3,5‐DTBCat=3,5‐di‐tert‐butylcatecholato; DTBbpy=4,4′‐di‐tert‐butyl‐2,2′‐bipyridine) afforded the dimeric {[NiII(3,5‐DTBSQ)(DTBbpy)](PF6)}2({[Ni](PF6)}2; 3,5‐DTBSQ=3,5‐di‐tert‐butylsemiquinonato) and monomeric semiquinonato (SQ) complexes [MII(3,5‐DTBSQ)(DTBbpy)](PF6) (M=Pd ([Pd](PF6)) and Pt ([Pt](PF6))). The negative solvatochromic properties of the SQ complexes allowed us to estimate the relative order of their dipole moments:[Pd](PF6)>[Pt](PF6)>{[Ni](PF6)}2. The complexes[Pd](PF6)and[Pt](PF6)adopt monomeric structures and are stable in CH2Cl2and toluene, whereas they gradually disproportionate at room temperature to[M]and 3,5‐di‐tert‐butylbenzoquinone (3,5‐DTBBQ) in polar solvents such as THF, MeOH, EtOH, DMF, or DMSO. The results of spectroscopic studies suggested that the oxidized nickel complex adopts a monomeric structure ([Ni](PF6)) in CH2Cl2, but a dimeric structure ({[Ni](PF6)}2) in the other investigated solvents. In polar solvents,{[Ni](PF6)}2may disproportionate to[Ni]and 3,5‐DTBBQ at 323 K, thereby demonstrating a significant solvent‐ and metal‐dependence in temperature. The relative activities of{[Ni](PF6)}2and[M](PF6)toward disproportionation are related to the electrochemically estimatedKdisvalues in CH2Cl2and DMF. The present work demonstrates that solvent polarity and the dipole moments of the SQ complexes promote disproportionation, which can be controlled by a judicious choice of the metal ion, solvent, and temperature.