Mononuclear Complexes of Cr(II) and Fe(II) with Terminal -SH Groups. Synthesis and X-Ray Crystal Structures of trans-M(SH)₂(dmpe)₂ (M = Cr, Fe; dmpe = 1,2-Bis(Dimethylphosphino)Ethane)

Abstract

The reaction of two equivalents of NaSH with MCl₂(dmpe)₂ (M = Cr, Fe,) at—78°C gives trans-M(SH)₂(dmpe)₂ (M = Cr, (1), 30%; Fe, (2) 98%). The complexes have been characterized spectroscopically, and the trans geometry has been confirmed by single crystal X-ray diffraction studies. Crystal data (1): C₁₂H₃₄CrP₄S₂, M= 418.42, monoclinic, P2₁/n, a = 8.857 (I), b= 12.719 (2), c = 9.648 (I) Å, β = 92.14(1)°, U= 1086.2 (5)Å, D _c = 1.279gcm⁻³, Z = 2, λ(MoK_a) = 0.71073 Å, (graphite mono-chromator), μ(MoK_a) = 9.80cm⁻¹. Methods: MULTAN, difference Fourier, full-matrix least-squares. Refinement of 1149 reflections (I > 3σ(I)) out of 1901 unique observed reflections (3.0° < 29 < 48.0°) gave R and R _w values of 0.092 and 0.096, respectively. Crystal data (2): C₁₂H₃₄FeP₄S₂, M = 422.28, monoclinic, P2₁/n, a = 8.834 (2), b = 12.594 (2), c = 9.532 (2) Å, β = 90.66 (2)°, U = 1060.3 (5) ų, D _c = 1.323 g cm⁻³, Z = 2, γ(MoK_a) = 0.71073 Å, (graphite monochromator), μ(MoK_a) = 11.87 cm⁻¹. Methods: same as for (1). Refinement of 1178 reflections (I > 3σ (I)) out of 2086 unique observed reflections (2.0° < 20 < 50.0°) gave R and R _w values of 0.056 and 0.059, respectively.

Key Words:

• X-ray
• chromium
• iron
• phosphine
• SH
• complex