Rare examples of diphenoxido-bridged trinuclear NiII2FeIII complexes with a reduced salen type Schiff base ligand: Structures and magnetic properties. (14th December 2017)

• Record Type: Journal Article
• Authors: Hazari, Alokesh; Gómez-García, Carlos J.; Drew, Michael G.B.; Ghosh, Ashutosh
• Is Part Of: Polyhedron. Volume 138(2017)
• Page Start: 145
• Page End: 153
• Publication Date: 2017-12-14
• Subjects: Nickel(II) -- Iron(III) -- μ1, 3-azido bridging -- Reduced Schiff base -- Magnetic properties; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2017.09.012
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Three novel trinuclear Ni II 2 Fe III structures with reduced salen-type Schiff base ligand show antiferromagnetic and ferromagnetic exchange interaction. Abstract: Three new trinuclear hetero-metallic complexes, [(NiL R )2 Fe(N3 )3 ] (1 ), [(NiL R (H2 O))2 Fe(C6 H5 CH2 CO2 )2 ]·(HSO4 ) (2 ) and [(NiL R (H2 O))2 Fe(C6 H5 CO2 )2 ]·(HSO4 )·(H2 O)·(CH2 Cl2 ) (3 ) have been synthesized using [NiL R ] as a "metalloligand" (where H2 L R = N, N′-bis(2-hydroxybenzyl)-1, 3-propanediamine). All complexes have been characterized by elemental analysis, spectroscopic methods, single crystal XRD and magnetic study. In the angular trinuclear units of1, the two terminals [NiL R ] coordinate through double phenoxido bridges to the central Fe III ion which is penta-coordinated having terminally coordinated azide ion. The two terminal Ni II centers are connected to each other and also to neighbouring units through μ 1, 3 -azido bridges to form an alternating chain. On the other hand, complexes, 2 and3 are linear discrete trinuclear species [Ni II –Fe III –Ni II ] in which two terminal octahedral [NiL R ] units coordinate to the central octahedral Fe III ion, located on a crystallographic centre of symmetry, through a μ2 -phenoxido oxygen atom and a bridging carboxylato ion. Variable temperature magnetic susceptibility measurements show the presence of antiferromagnetic exchange interactions in1 mediated through the phenoxido bridges ( J 1 = −33.2 cm −1, ) and μ 1, 3 -N3 single bridges ( J 2 = −19.9 cm −1 and J 3 = −16.7 cm −1 ). On the other hand, compounds2 and3 show ferromagnetic coupling interactions mediated through the double phenoxido bridges with J values of +4.9 and +3.0 cm −1 for2 and3, respectively.