Two tetranuclear [Ni(II)/Dy(III)] ₂ solvatomorphs based on symmetric bicompartmental Schiff base type ligand

From the system [Ni( o - van - en ) ] — DyBr 3 , a novel tetranuclear complex [Ni( o - van - en ) Dy(H 2 O) 2 (OH)] 2 Br 4 ·6H 2 O (1) was isolated; H 2 ( o - van - en ) was synthesized by 2/1 condensation of o -vanillin and ethylenediamine. Single crystals (SC) of 1, upon standing in methanol/isopropanol mother liquor, underwent a SC-SC transformation and yielded a new solvatomorph [Ni( o - van - en )Dy(H 2 O) 2 (OH)] 2 Br 4 ·MeOH· i PrOH·H 2 O (2). Both complexes, 1 and 2, were characterized by elemental analysis, infrared spectroscopy, and single crystal X-ray analysis. Crystal structures of both 1 and 2 are ionic. Within the bicompartmental unit {Ni( o - van - en )Dy(H 2 O) 2 ( m -OH)}, the square coordinated Ni(II) atom occupies the smaller cavity (donor set is cis -N 2 O 2 ) while the octacoordinated Dy(III) atom (donor set is O 8 ) is placed in the larger cavity. The two [Ni( o - van - en )Dy(H 2 O) 2 ( m -OH)] units are linked by a pair of m -OH bridging ligands. The unit cell content is completed by bromide anions and water (1) or methanol, isopropanol, and water solvate molecules (2).