Spectroscopic and structural characterization of cationic N-(2-aminoethyl)aziridine-N,N′ chelate complexes of the d6-metals Rh(III) and Ir(III)

The syntheses of the compounds [M(Cp∗)(aeaz)(az)](OTf)2 (4, 5) (M = Rh(III), Ir(III); aeaz = C2H4NC2H4NH2, az = C2H4NH (3)) containing cationic N-(2-aminoethyl)aziridine-N,N′ chelate complexes are described. The bis-aziridine complexes [MCl(Cp∗)(az)2]Cl (M = Rh (1), M = Ir (2)) react with an excess of the aziridine (az) in the presence of AgO3SCF3 (=AgOTf) via AgCl precipitation and az addition followed by a metal-mediated coupling reaction, to give the compounds [M(Cp∗)(aeaz)(az)](OTf)2 (4, 5). The new aeaz ligand is formally the dimerisation product of az. Using the same reaction conditions with the analogous, but weaker Lewis acidic ruthenium(II) complex [RuCl(C6Me6)(az)2]Cl (6) an anion exchange reaction yielding [RuCl(C6Me6)(az)2]OTf (8) is observed. After purification, all compounds are fully characterized using IR, FAB-MS, 1H and 13C NMR spectroscopy. The single crystal X-ray structure analysis reveals a distorted octahedral geometry for all complexes.

The bis-aziridine complexes [MCl(Cp∗)(az)2]Cl (M = Rh (1), Ir (2), az = C2H4NH) react with AgO3SCF3 = AgOTf and an additional aziridine ligand (az) via a metal-mediated coupling reaction to give the compounds [MCp∗(aeaz)(az)](OTf)2 (M = Rh (4), Ir (5), aeaz = C2H4NC2H4NH2). The ORTEP plot of the Rh complex 4 is illustrated. The formed ligand aeaz is formally the dimer of az.Figure optionsDownload as PowerPoint slide