Binuclear manganese(II) and nickel(II) complexes with a potentially octadentate macrocyclic ligand (H 4L1): synthesis and characterisation. X-ray crystal structures of [Mn 2(H 2L1 )(CH 3COO) 2]·2CH 3OH and [Ni 2(H 2L1 )(H 2O) 2Cl 2]·2H 20

Abstract

A series of binuclear manganese(II) and nickel(II) complexes of the macrocyctic ligand H 4L1 has been prepared and characterised. ([Mn 2(H 2L1)A 2], where A=Cl −, Br −, NO 3 −, NCS −, CH 3COO − or N 3 −; [Ni 2(H 2L1)X 2Y 2], where X=Cl −, Br − or NO 3 − and Y= H 20, [Ni 2(H 2L1)(NCS) 2(C 2H 5OH)] and [Ni 2(H 2L1)(CH 3COO) 2]·2H 2O). The macrocycle is formed by Schiff base condensation of two molecules of 2,6-diformyl-4-methylphenol with two molecules of 1,3-diamino-2-hydroxypropane in the presence of Ni(lI) or Mn(II) as template ion. The complexes are all binuclear with the two metal ions bridged by the deprotonated phenolate donors of the macrocycle. The alcohol groups of the macrocyclic ligand do not coordinate to the metal ions. The complexes have been characterised by analytical, spectroscopic, electrochemical and magnetic susceptibility measurements and the single crystal X-ray structures of [Mn 2(H 2L1)(CH 3COO) 2]·2CH 3OH (triclinic, P 1 , a=8.701, b= 10.258, c=10.612 Å, α=62.44, β=67.83, γ= 77.74°, V=776.8 Å 3, Z=1) and of [Ni 2(H 2L1)(H 2O) 2Cl 2]·2H 2O (rhombohedral, R 3 , a=28.885, c=9.783 Å, V=7069 Å 3, Z=9) have been determined.