Crystal Structures of Two Re(V) Complexes of 3,5-Dimethylpyrazole with Linear and Bent [OReOReO]4+ Fragments

The crystal structures of two new dimer compounds of Re(V) containing an [OReOReO]4+ fragment have been studied. Re2O3Cl4(3,5-Me2pzH)4 (I): space group P21/n, Z = 4, a = 10.180(3), b = 18.132(3), c = 16.601(2) Å, β = 94.60(2)°, V = 3054.4(1) Å3, dcalc = 2.059 g/cm3, R1 = 0.0513, wR2 = 0.1493 for 4701 Ihkl > 2 σI of 4926 measured reflections; Re2O3Cl2(μ-3,5-Me2pz)2(3,5-Me2pzH)2⋅2[(3,5-Me2pzH2)Cl] (II): space group P21/n, Z = 4, a = 16.904(2), b = 14.573(1), c = 17.401(2) Å, β = 107.23(1)°, V = 4094.2(7) Å3, dcalc = 1.848 g/cm3, R1 = 0.025, wR2 = 0.0514 for 6102 Ihkl > 2 σI of 6315 measured reflections (Enraf-Nonius CAD-4 diffractometer, λMoKα, graphite monochromator). Compound I has a molecular structure, where molecules are dimers Re2O3Cl4(3,5-Me2pzH)4 with a bridging O atom. In II, the dominant motif is the ReOCl(3,5-Me2pzH) fragments bridged by the pyrazole molecules and the O atom.