“…To date the metal free species [TPyz27PzH 2 ] [116] and its complexes with Mg II [67,123], transition metals (Fe II [198,199] [74], lanthanides (Er III , Tm III , Yb III , Lu III [78,201]) were synthesized and characterized to a different extent. The complexes were prepared by direct template cyclotetramerization of the dinitrile in the presence of the corresponding metal salt in a melt or in the solvent ( A c c e p t e d M a n u s c r i p free species [TPyz27PzH 2 ] was prepared either by reaction of the dinitrile precursor with Li in amyl alcohol or, better, through the demetallation of the Mg II complex upon reprecipitation from sulfuric acid [116].…”