2 research outputs found
Nickel(II) 3,4;9,10-Perylenediimide bis-Phosphonate Pentahydrate: A MetalâOrganic Ferromagnetic Dye
The new metalâorganic compound nickel(II) 3,4;9,10-
perylenediimide bis-phosphonate pentahydrate, i.e. Ni2[(PDI-BP)-
(H2O)2]·3H2O (1), has been synthesized and its structural and magnetic
properties have been studied. Reaction of 3,4;9,10-perylenediimide bisphosphonate
(PDI-BP, hereafter) ligand and nickel chloride in water resulted
in the precipitation of a red and poorly crystalline solid (1). As the solid shows
a poor crystalline organization of aggregates, the energy dispersive X-ray
diffraction analysis (EDXD) technique has been used to obtain short-range
order structural information of the single nanoaggregates by radial distribution
function analysis. The overall structure of the compound is characterized by
layers containing perylene planes shifted in the direction perpendicular to the
stacking axes in such a way that only the outer rings overlap. The edges of the
perylene planes are connected to the phosphonate groups through an imido
group. The oxygen atoms of the [âPO3]2â group and those of the water
molecules are bonded to the nickel ions resulting in a [NiO6] octahedral coordination sphere. The NiâO bond lengths are 0.21
± 0.08 nm and the NiâOâNi angles of aligned moieties are 95 ± 2°. The oxygen atoms of the water molecules and the nickel
atoms are nearly planar and almost perpendicular to the perylene planes forming chains of edge-sharing octahedra. The magnetic
properties of (1) show the presence of intrachain ferromagnetic NiâNi interactions and a long-range ferromagnetic order below
21 K with a canting angle and with a spin glasslike behavior due to disorder in the inorganic layer. Hysteresis cycles show a
coercive field of ca. 272 mT at 2 K that decreases as the temperature is increased and vanishes at ca. 20 K