Abstract
Two new cyanide-bridged 3d–4f hetero-dinuclear complexes, namely Ln(DMF)4(H2O)3(μ-CN)Co(CN)5 · H2O (Ln = Nd (1) and Gd (2), DMF = N,N-dimethylformamide), were synthesized by the facile reaction of LnCl3 · 6H2O and K3Co(CN)6. Characterization includes microanalysis, IR spectrometric identifications, X-ray crystallographic analysis and magnetic properties. Both 1 and 2 crystallize in the centrosymmetric monoclinic space group P 2 /n (No. 14) with Z = 4. The lanthanide(III) ions are eight-coordinate in a square-antiprism arrangement, while cobalt(III) ions are six-coordinate in an octahedral environment in each complex. A cyanide bridge links an Ln(III) ion to a Co(III) ion. Molecules in the crystal cell of each compound are held together by van der Waals forces and a network of hydrogen bonding. Magnetic analysis shows that antiferromagnetic interactions are observed below 7 K for both 1 and 2, which are attributed to intermolecular interactions between the Ln(III) ions in the network through hydrogen bonds. This series of compounds may be of importance in photo-induced magnetism because of the cyanide bridge between 3d and 4f metals.
Acknowledgments
This work is supported by Grant-in-aid for the 21st century COE program “Keio Life Conjugate Chemistry” from the Ministry of Education, Culture, Sports, Science and Technology, Japan. The authors are grateful to the Research Center for Structural and Functional Proteomics, Institute for Protein Research, Osaka University for the use of the Cambridge Structural Database System (CSD).