Complexes of Manganese, Iron, Zinc, and Molybdenum with a Superbasic Tris(guanidine) Derivative of Tris(2-ethylamino)amine (Tren) as a Tripod Ligand

The synthesis of the novel tripod ligand N[CH2CH2N=C(NMe2)2]3, based on the tris(2-ethylamino)amine (tren) backbone and having a set of three superbasic tetramethylguanidine (TMG) donor atoms instead of the primary amine functionalities, is described. This ligand has been prepared by treating tren with the Vilsmeyer salt [(Me2N)2CCl]Cl in the presence of triethylamine as an auxiliary base and NaOH. Complexes of manganese(II), iron(II), and zinc(II) as biologically relevant transition metal ions as well as of molybdenum(0) have been synthesized and spectroscopically and structurally characterized. The electrochemical properties of selected complexes have been studied.