Synthesis of a macrocyclic metal complex incorporating peripheral hydroxyethyl tails: The X-ray structure of [Mn(L¹)Cl][BF₄]·4H₂O

Reaction of 2,9-dichloro-1,10-phenanthroline with 2-hydroxyethylhydrazine leads to the isolation of 2,9-di(N-2′-hydroxyethylhydrazino)-1,10-phenanthroline in moderate yield. This species undergoes a template condensation reaction with 2,6-diacetylpyridine in the presence of MnCl₂·4H₂O to give the title complex of the macrocyclic ligand L¹. The X-ray structure of the complex shows the six-co-ordinate nature of the metal ion which is bound by five N-donors of the macrocycle and is displaced 0.51 Å towards the axial chlorine ligand. The hydroxyethyl tails extend up on the same side of the ligand as the axial chlorine. The complex crystallises in orthorhombic space group Pnma with a = 13.225(4), b = 25.011(4), and c = 17.343(4) Å. The structure was refined to R = 0.103 for 1 323 reflections.