Weinert Hanns Micha, Wölper Christoph, Radović Aleksa, Cutsail George E, Siera Hannah, Haberhauer Gebhard, Schulz Stephan
Institute of Inorganic Chemistry, University of Duisburg-Essen, Universitätsstraße 5-7, 45141, Essen, Germany.
Max Planck Institute for Chemical Energy Conversion (CEC), Stiftstraße 34-36, 45470, Mülheim a. d. Ruhr, Germany.
Chemistry. 2024 May 2;30(25):e202400204. doi: 10.1002/chem.202400204. Epub 2024 Mar 18.
Diarsene [L(MeO)GaAs] (L=HC[C(Me)N(Ar)], Ar=2,6-PrCH, 4) reacts with MeOTf and NHC (NHC=1,3,4,5-tetra-methylimidazol-2-ylidene) to the diarsene [L(TfO)GaAs] (5) and the carbene-coordinated diarsene [L(MeO)GaAsAs(NHC)Ga(OMe)L] (6). The NHC-coordination results in an inversion of the redox properties of the diarsene 4, which shows only a reversible reduction event at E=-2.06 V vs Fc, whereas the carbene-coordinated diarsene 6 shows a reversible oxidation event at E=-1.31 V vs Fc. Single electron transfer reactions of 4 and 6 yielded [K[2.2.2.]cryp][L(MeO)GaAs] (8) and [L(MeO)GaAsAs(NHC)-Ga(OMe)L][B(CF)] (9) containing the radical anion [L(MeO)GaAs]⋅ (8⋅) and the NHC-coordinated radical cation [L(MeO)GaAsAs(NHC)Ga(OMe)L]⋅ (9⋅), respectively, while the salt-elimination reaction of the triflate-coordinated diarsene 5 with Na[B(CF)] gave [LGaAs][B(CF)] (11) containing the dication [LGaAs] (11). Compounds 1-11 were characterized by H and C NMR, EPR (8, 9), IR, and UV-Vis spectroscopy and by single crystal X-ray diffraction (sc-XRD). DFT calculations provided a detailed understanding of the electronic nature of the diarsenes (4, 6) and the radical ions (8⋅, 9⋅), respectively.
二砷烯[L(MeO)GaAs]（L = HC[C(Me)N(Ar)]，Ar = 2,6 - PrCH₂，4）与三氟甲磺酸甲酯（MeOTf）和氮杂环卡宾（NHC = 1,3,4,5 - 四甲基咪唑 - 2 - 亚基）反应生成二砷烯[L(TfO)GaAs]（5）和卡宾配位的二砷烯[L(MeO)GaAsAs(NHC)Ga(OMe)L]（6）。氮杂环卡宾配位导致二砷烯4的氧化还原性质发生反转，二砷烯4在相对于二茂铁（Fc）的E = -2.06 V处仅显示一个可逆还原事件，而卡宾配位的二砷烯6在相对于二茂铁的E = -1.31 V处显示一个可逆氧化事件。4和6的单电子转移反应分别生成含有自由基阴离子[L(MeO)GaAs]⁻（8⁻）的[K[2.2.2]crypt][L(MeO)GaAs]（8）和含有氮杂环卡宾配位的自由基阳离子[L(MeO)GaAsAs(NHC)Ga(OMe)L]⁺（9⁺）的[L(MeO)GaAsAs(NHC)Ga(OMe)L][B(C₆F₅)₄]（9），而三氟甲磺酸根配位的二砷烯5与Na[B(C₆F₅)₄]的脱盐反应生成含有双阳离子[LGaAs]²⁺（11）的[LGaAs][B(C₆F₅)₄]（11）。化合物1 - 11通过¹H和¹³C核磁共振、电子顺磁共振（8, 9）、红外光谱以及紫外 - 可见光谱进行表征，并通过单晶X射线衍射（sc - XRD）进行结构测定。密度泛函理论（DFT）计算分别详细地阐明了二砷烯（4, 6）和自由基离子（8⁻, 9⁺）的电子性质。
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