Affiliation:
1. Institute of Inorganic Chemistry University of Duisburg-Essen Universitätsstraße 5–7 45141 Essen Germany
2. Max Planck Institute for Chemical Energy Conversion (CEC) Stiftstraße 34–36 45470 Mülheim a. d. Ruhr Germany
3. Institute of Organic Chemistry University of Duisburg-Essen Universitätsstraße 5–7 45141 Essen Germany
4. Center for Nanointegration Duisburg-Essen (CENIDE) University of Duisburg-Essen Carl-Benz-Straße 199 47057 Duisburg Germany
Abstract
AbstractDiarsene [L(MeO)GaAs]2 (L=HC[C(Me)N(Ar)]2, Ar=2,6‐iPr2C6H3, 4) reacts with MeOTf and MeNHC (MeNHC=1,3,4,5‐tetra‐methylimidazol‐2‐ylidene) to the diarsene [L(TfO)GaAs]2 (5) and the carbene‐coordinated diarsene [L(MeO)GaAsAs(MeNHC)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 E1/2=−2.06 V vs Fc0/+1, whereas the carbene‐coordinated diarsene 6 shows a reversible oxidation event at E1/2=−1.31 V vs Fc0/+1. Single electron transfer reactions of 4 and 6 yielded [K[2.2.2.]cryp][L(MeO)GaAs]2 (8) and [L(MeO)GaAsAs(MeNHC)‐Ga(OMe)L][B(C6F5)4] (9) containing the radical anion [L(MeO)GaAs]2⋅− (8⋅−) and the NHC‐coordinated radical cation [L(MeO)GaAsAs(MeNHC)Ga(OMe)L]⋅+ (9⋅+), respectively, while the salt‐elimination reaction of the triflate‐coordinated diarsene 5 with Na[B(C6F5)4] gave [LGaAs]2[B(C6F5)4]2 (11) containing the dication [LGaAs]22+ (112+). Compounds 1–11 were characterized by 1H and 13C 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.
Funder
Deutsche Forschungsgemeinschaft