Abstract
The heterobimetallic complexes [Mn(iPrNPPh2)3Cu(iPrNHPPh2)] (1) and [Fe(iPrNPPh2)3Cu(iPrNHPPh2)] (2) have been synthesized by the
one pot reaction
of LiNiPrPPh2, MCl2 (M = Mn, Fe), and CuI in high yield. Addition of excess CuI into 2 or directly to the reaction mixture led to the formation
of a heterotrimetallic [Fe(iPrNPPh2)3Cu2(iPrNPPh2)] (3) in good yield. Complexes 1–3 have been characterized by means of elemental
analysis, paramagnetic 1H NMR, UV–vis spectroscopy,
cyclic voltammetry, and single crystal X-ray analysis. In all three
complexes, Mn or Fe are in the +2 oxidation state and have a high
spin electron configuration, as evidenced by solution Evans’
method. In addition, the oxidation state of Fe in complex 3 is confirmed by zero-field 57Fe Mössbauer spectroscopy.
X-ray crystallography reveals that the three coordinate Mn/Fe centers
in the zwitterionic complexes 1–3 adopt an unusual trigonal planar geometry.