Triangulo -{Er III 3 } complex showing field supported slow magnetic relaxation.

The triangulo -{Er 3 } complex [Er 3 Cl( o-van ) 3 (OH) 2 (H 2 O) 5 ]Cl 3 · n H 2 O ( n = 9.4; H( o-van ) = o -vanillin) (1) was generated by an in situ method. The isolated Er(iii) complex 1 was characterized by elemental analysis and molecular spectroscopy. The results of single crystal X-ray diffraction studies have shown that 1 is built up of trinuclear [Er 3 Cl( o-van ) 3 (OH) 2 (H 2 O) 5 ] 3+ complex cations, chloride anions and water solvate molecules. Within the complex cation the three Er(iii) central atoms are placed at the apexes of a triangle which are bridged by three ( o-van ) - ligands with additional chelating functions and two μ 3 -OH - ligands. Additionally five aqua and one chlorido ligands complete the octa-coordination of the three Er(iii) atoms. AC susceptibility measurements reveal that the compound exhibits slow magnetic relaxation with two relaxation modes.