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Published on: April 14, 2020
Formation and structural characterization of a europium(II) mono(scorpionate) complex and a sterically crowded
Phil Liebing1, Marcel Kühling2, Josef Takats3
1ETH Zürich, Laboratorium für Anorganische Chemie, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland.
Abstract:
The reaction of EuI2(THF)2 with potassium hydro-tris-(3,5-diiso-propyl-pyrazol-yl)borate (K[HB(3,5- pz)3] (= KTp , pz = pyrazol-yl) in a molar ratio of 1:1.5 resulted in extensive ligand fragmentation and formation of the europium(II) mono(scorpionate) complex bis-(3,5-diisopropyl-1H-pyrazole)[hydro-tris-(3,5-diiso-propyl-pyrazol-yl)borato]iodido-europium(II), [Eu(C27H46BN6)I(C9H16N2)2] or (Tp )(3,5- pzH)2EuIII, 1, in high yield (78%). As a typical by-product, small amounts of the sterically crowded pyraza-bole derivative trans-4,8-bis-(3,5-diiso-propyl-pyrazol-1-yl)-1,3,5,7-tetra-iso-propyl-pyraza-bole, C36H62B2H8 or trans-{(3,5- pz)HB(μ-3,5- pz)}2, 2, were formed. Both title compounds have been structurally characterized through single-crystal X-ray diffraction. In 1, two isopropyl groups are each disordered over two orientations with occupancy ratios of 0.574 (10):0.426 (10) and 0.719 (16):0.281 (16). In 2, one isopropyl group is similarly disordered, occupancy ratio 0.649 (9):0.351 (9).
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