Mononuclear barium and dinuclear copper(II) complexes of a 24-membered bibracchial tetraimine Schiff-base macrocycle derived from N,N-bis(2-aminoethyl)-2-methoxyethylamine

Abstract

The X-ray structure of a mononuclear barium complex of the bibracchial tetraimine Schiff-base macrocycle derived from the cyclocondensation of 2,6-diacetylpyridine and N,N-bis(2-aminoethyl)-2-methoxyethylamine [monoclinic, space group P2/n(no. 13), a= 27.494(20), b= 14.120(13), c= 21.024(14)Å, β= 91.68(57)°, Z= 8] confirms that the macrocycle folds to present a molecular cleft within which the metal is co-ordinated. Transmetallation with Cu^II gives a homodinuclear copper(II) complex the crystal structure of which [monoclinic, space group P2₁/c, a= 14.807(6), b= 9.558(4), c= 17.432(8)Å, β= 113.89(5)°, Z= 2] shows that the copper(II) atoms are held by the ‘head’ units of the macrocycle, an opening of the cleft having occurred.