Syntheses, structures, and magnetic properties of dicyanamide bridged one-dimensional double chain and discrete dinuclear complexes of manganese(II) derived from 6,7-dimethyl-2,3-di(2-pyridyl)quinoxaline or 2,4,6-tri(2-pyridyl)-1,3,5-triazine

Abstract

Syntheses, structures, and magnetic properties of two dicyanamide (dca) bridged compounds of manganese(II), [Mn II(DMeDPQ)(μ 1,5-dca) 2] n ( 1) and [ Mn 2 II ( TPT ) 2 ( μ 1 , 5 -dca ) 2 ( H 2 O ) 2 ] ( ClO 4 ) 2 ( 2 ) , have been described (DMeDPQ = 6,7-dimethyl-2,3-di(2-pyridyl)quinoxaline; TPT = 2,4,6-tri(2-pyridyl)-1,3,5-triazine). While 2 is a discrete dinuclear compound, the structure of 1 is polymeric and consists of one-dimensional double chains. DMeDPQ and TPT behave here as bidentate and tridentate chelating ligands, respectively. The one-dimensional double chain structure in 1 is formed due to the dual existence of two single and two double end to end (μ 1,5-, EE) dca ligands. In the case of 2, the metal centers are bridged by two double EE dca ligands. The variable-temperature magnetic susceptibility measurements of both compounds reveal that dicyanamide mediates a weak antiferromagnetic interaction between the metal centers.