Hexacyanometallate anions as precursors of two new trinuclear heterobimetallic assemblies: Syntheses, structures and cryomagnetic properties

Abstract

Two new cyano bridged Cu–Co and Cu–Fe trinuclear bimetallic assemblies, [(CuL)[Co(CN) 6](CuL)]ClO 4 · 3.5H 2O ( 1) and [(CuL)[Fe(CN) 6](CuL)] · 13H 2O ( 2) where [L = (3 E,5 E)- N 1, N 4-bis((pyridin-2-yl)methylene)butane-1,4-diamine] have been prepared using cyanometallates as anion precursors and characterised by elemental analyses, spectroscopic studies, single crystal X-ray diffraction and cryomagnetic susceptibility measurements. Magneto-structural correlations have been drawn from cryomagnetic susceptibility measurements over a wide temperature range (2–300 K) under 0.5 T magnetic fields. Weak antiferromagnetic interactions with J = −0.81 and −0.73 cm −1 are found for 1 and 2, respectively, showing a very weak coupling, as expected from the diamagnetic long chain –NC–Co–CN–CN– and –NC–Fe–CN–CN– bridges revealed from the single crystal X-ray diffraction studies.