Synthese und Struktur des Mangan(II)‐L‐aspartat‐trihydrats, Mn(L‐Asp) · 3H₂O

Synthesis and Structure of Manganese(II) L‐Aspartate Trihydrate, Mn(L‐Asp)· 3H₂O Manganese L‐aspartate chloride, Mn(L‐AspH)Cl, has been prepared from equimolar quantities of MnCl₂ and Mn(L‐AspH)₂ in water. This material can be converted into the title compound by treatment with aqueous KOH, and crystallized as a trihydrate from solutions kept at pH = 7.85. The compound has been characterized by elemental analysis and by single crystal X‐ray structure determination. In the crystal, the aspartate dianion functions as a facially tridentate ligand to the Mn(II) center whose octahedral coordination sphere is completed by two water molecules and a carboxylate oxygen atom from a neighboring complex in trans position to the amino group. The stereochemistry of this coordination mode is different from that in the analogous magnesium compound, but similar to that in the cobalt(II) and zinc(II) analogues. The third water molecule is a hydrogen‐bonded crystal water.