Formation and structural characterization of a europium(II) mono(scorpionate) complex and a sterically crowded pyraza­bole

The reaction of EuI(2)(THF)(2) with potassium hydro­tris­(3,5-diiso­propyl­pyrazol­yl)borate (K[HB(3,5-(iPr2)pz)(3)] (= KTp(iPr2), pz = pyrazol­yl) 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)[hydro­tris­(3,5-diiso­propyl­pyrazol­yl)borato]iodido­europium(II), [Eu(C(27)H(46)BN(6))I(C(9)H(16)N(2))(2)] or (Tp(iPr2))(3,5-(iPr2)pzH)(2)Eu(II)I, 1, in high yield (78%). As a typical by-product, small amounts of the sterically crowded pyraza­bole derivative trans-4,8-bis­(3,5-diiso­propyl­pyrazol-1-yl)-1,3,5,7-tetra­iso­propyl­pyraza­bole, C(36)H(62)B(2)H(8) or trans-{(3,5-(iPr2)pz)HB(μ-3,5-(iPr2)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).