A Tetranuclear Manganese Cluster with a Star‐Shaped Mn4O6 Core Motif: Directed Synthesis using a Mononuclear Precursor Complex

The tetranuclear manganese(II) complex [Mn₄(ppi)₆](BPh₄)₂ ( 2 ) (Hppi = 2‐pyridylmethyl‐2‐hydroxy phenylimine) is prepared by using the precursor complex [Mn(ppi)₂]·H₂O ( 1 ). Based on UV/Vis‐ and IR‐spectroscopy data in combination with mass spectrometry it has been concluded that 1 is a mononuclear neutral Mn^II complex, in which two ppi ligands chelate the manganese atom. Compound 2 crystallizes in the triclinic space group P1¯ (no. 2), with a = 17.500(3), b = 17.955(4), c = 19.101(4) Å, α = 113.79(3)°, β = 111.33(3)°, γ = 93.91(3)°, V = 4950(2) ų and Z = 2. In the tetranuclear [Mn₄(ppi)₆]²⁺ complex cation Mn(1), Mn(2), and Mn(3) are equivalently coordinated by two deprotonated Hppi ligands leading to a N₄O₂ donor set. The environment of the central Mn(4) is formed by coordination of three [Mn(ppi)₂] fragments resulting in a phenoxo bridged star‐shaped Mn₄O₆ core motif. The average distance of directly adjacent manganese ions is 3.310 Å, whereas the average distance of Mn(1), Mn(2), and Mn(3) among each other is 5.732 Å.