Synthesis, structure and metallation of spiro-N3P3(O2C12H8)(OC5H4N-2)4: A heptacoordinate Co(II) in the molecular structure of N3P3(O2C12H8)(OC5H4N-2)4 · Co(NO3)2

Spiro-N3P3(O2C12H8)(OC5H4N-2)4 (L) is an efficient multi-site coordination ligand which binds with transition metal ions to afford the mononuclear complexes [LCu(NO3)2], [LCo(NO3)2] and [LZnCl2]. In [LCu(NO3)2] the copper atom is six-coordinate with the cyclophosphazene ligand coordinating to the metal ion through one skeletal ring nitrogen atom and two nitrogen atoms of geminal pyridyloxy substituents in a η3-gem-N3 mode. The two nitrate ligands provide monodentate as well as chelating coordination. In [LCo(NO3)2] the coordination geometry around Co(II) is pentagonal bipyramidal with a 3N, 4O coordination environment. The cyclophosphazene ligand binds to the metal ion in a η3-non-gem-N3 mode. The two nitrate ligands function as chelating ligands and complete the coordination around cobalt. The coordination response of L in the complex [LZnCl2] is also η3-non-gem-N3. Two chloride ligands complete the coordination environment around zinc.

Graphical abstractSpiro-N3P3(O2C12H8)(OC5H4N-2)4 (L) is an efficient multi-site coordination ligand which binds with transition metal ions to afford the mononuclear complexes [LCu(NO3)2], [LCo(NO3)2] and [LZnCl2]. The ligand L shows diverse coordination behavior towards these metal ions.Figure optionsDownload full-size imageDownload as PowerPoint slide