Reduced Arene Complexes of Scandium
Reduced Arene Complexes of Scandium
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DOI：
10.1002/chem.202000946
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发表时间：
2020-03
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影响因子：
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通讯作者：
Priyabrata Ghana;A. Hoffmann;T. Spaniol;J. Okuda
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作者：
Priyabrata Ghana;A. Hoffmann;T. Spaniol;J. Okuda
摘要：碱金属萘化物或蒽化物与钪(III)苯胺化物[Sc(X){N(tBu)Xy}₂(thf)]（X = N(tBu)Xy（1）；X = Cl（2）；Xy = C₆H₃ - 3,5 - Me₂）反应，生成含还原芳烃配体的钪配合物[M(thf)ₙ][Sc{N(tBu)Xy}₂(RA)]（M = Li - K；n = 1 - 6；RA = C₁₀H₈²⁻（3 - Naph - K）和C₁₄H₁₀²⁻（3 - Anth - M））。单晶X射线衍射表明，钪(III)中心以σ²:π - 配位模式与萘二阴离子键合，而蒽二阴离子以σ² - 方式对称地连接到钪(III)中心。所有化合物都通过多核（包括⁴⁵Sc NMR光谱）进行了表征。对这些颜色鲜艳的芳烃配合物进行的量子化学计算证实钪处于 +3氧化态。在紫外/可见光谱中观察到的强烈吸收是由于配体到金属的电荷转移。腈与还原的芳烃配体发生C - C偶联反应，而与一当量的[NEt₃H][BPh₄]反应导致还原的芳烃配体单质子化。
Abstract Alkali metal naphthalenide or anthracenide reacted with scandium(III) anilides [Sc(X){N(tBu)Xy}2(thf)] (X=N(tBu)Xy (1); X=Cl (2); Xy=C6H3‐3,5‐Me2) to give scandium complexes [M(thf)n][Sc{N(tBu)Xy}2(RA)] (M=Li–K; n=1–6; RA=C10H8 2− (3‐Naph‐K) and C14H10 2− (3‐Anth‐M)) containing a reduced arene ligand. Single‐crystal X‐ray diffraction revealed the scandium(III) center bonded to the naphthalene dianion in a σ2:π‐coordination mode, whereas the anthracene dianion is symmetrically attached to the scandium(III) center in a σ2‐fashion. All compounds have been characterized by multinuclear, including 45Sc NMR spectroscopy. Quantum chemical calculations of these intensely colored arene complexes confirm scandium to be in the oxidation state +3. The intense absorptions observed in the UV/Vis spectra are due to ligand‐to‐metal charge transfers. Whereas nitriles underwent C−C coupling reaction with the reduced arene ligand, the reaction with one equivalent of [NEt3H][BPh4] led to the mono‐protonation of the reduced arene ligand.