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

Two new cyano bridged Cu-Co and Cu-Fe trinuclear bimetallic assemblies, [(CuL)[Co(CN)(6)](CuL)1ClO(4) center dot 3.5H(2)O (1) and [(CuL)[Fe(CN)(6)](CuL) center dot 13H(2)O (2) where [L = (3E,5E)-N',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 I 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. (c) 2007 Elsevier Ltd. All rights reserved.