Antiferro- to ferromagnetic crossover in diphenoxido bridged NiII2MnII complexes derived from N2O2 donor Schiff base ligands. (15th October 2016)

• Record Type: Journal Article
• Authors: Seth, Piya; Figuerola, Albert; Jover, Jesús; Ruiz, Eliseo; Ghosh, Ashutosh
• Is Part Of: Polyhedron. Volume 117(2016)
• Page Start: 57
• Page End: 63
• Publication Date: 2016-10-15
• Subjects: Manganese -- Nickel -- Heterometallic complexes -- Magnetic properties -- Crossover angle; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2016.05.021
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Three new Ni(II)–Mn(II) complexes, derived from different Schiff base ligands, having very slight variations in average phenoxido bridging angles (97.27–97.35°) have been synthesized in order to analyze that small difference in structural parameters can be responsible for ferro- to antiferromagnetic crossover in this type of complexes. Abstract: Three new trinuclear Ni II –Mn II complexes have been synthesized using three different "metalloligands" [NiL 1 ], [NiL 2 ] and [NiL 3 ] derived from the Schiff bases H2 L 1 = N, N′-bis(salicylidene)-1, 3-pentanediamine, H2 L 2 = N, N′-bis(salicylidene)-1, 3-propanediamine and H2 L 3 = N, N′-bis(salicylidene)-1, 3, -diaminopropan-2-ol), respectively. In all three complexes, [(NiL 1 )2 Mn(OOCPh)2 (H2 O)2 ]·CH3 OH (1 ), [(NiL 2 )2 Mn(OOCPh)2 (CH3 OH)2 ]·CH3 OH (2 ) and [(NiL 3 )2 Mn(OOCPh)2 (H2 O)2 ]·CH3 OH (3 ), in addition to the double phenoxido bridge, the two terminal Ni II atoms are linked to the central Mn II by means of a syn–syn bridging benzoate, giving rise to a linear structure. Complex1 with Ni–O–Mn angle of 97.35° exhibits antiferromagnetic interactions ( JNi–Mn = −0.60 cm −1 ) whereas ferromagnetic exchange is observed in2 and3 ( JNi – Mn = +2.00 and +1.10 cm −1 respectively) having Ni–O–Mn angle 97.34° (in2 ), 97.27° (in3 ). Theoretical calculations have been performed in order to understand the effect of structural parameters that can tune the magnetic properties of this type of complexes such as small differences in the Ni–O–Mn angle and/or slight variations in intermolecular contacts within the crystal.