A LANTHANUM(III) COMPLEX OF A 6-NITROGEN DONOR MACROCYCLIC LIGAND WITH AROMATIC SIDE-CHAINS - SYNTHESIS, CRYSTAL-STRUCTURE AND SPECTRA

Yellow crystals of formula [La(CH3COO)(NCS)2(C26H18N6)] were synthesized by the condensation of 1,2-diaminobenzene and 2,6-pyridinedicarboxyaldehyde in the presence of lanthanum(III) acetate, followed by partial acetate-thiocyanate metathesis. The complex has been characterized by X-ray crystallography. The La(III) ion is 10-coordinate, being linked to the six nitrogen atoms of the macrocyclic ligand, to the nitrogen atoms of two isothiocyanates situated on opposite sides of the macrocycle and to a bidentate chelating acetate. The IR and NMR spectra (H-1 and C-13) of the complex were recorded and assigned.