Syntheses,crystal structures,magnetic behaviours,and thermal properties of three hydrogen-bonding networks containing dicyanamide and 4-hydroxypyridine

Three new dicyanamide-bridged polymeric complexes of { [ mn (dca) 2 (l) 2 ]·2 h 2 o } n (1),{ [ cd (dca) 2 (l) 2 ]·2 h 2 o } n (2),and { [ co (dca) 2 (l) 2 ] 2 (l) } n (3) (dca = dicyanamide,l = pyridinium-4-olate) have been synthesized and structurally characterized. in the three compounds,the protons of hydroxyl groups of 4-hydroxypyridine transfer to pyridyl nitrogen atoms. compounds 1 and 2 are isomorphous forming one-dimensional [ m (dca) 2 (l) 2 ] n chains where metals are connected by double dca anions. these one-dimensional chains are extended into two-dimensional layers through weak c-hn hydrogen bonds. further,these layers are assembled into a three-dimensional supramolecular network through n-ho,o-ho hydrogen bonds. complex 3 is a coordination layer of (4,4) topology with octahedral metal centers linked by four single 1,5-bridges. these layers are interlocked by n-ho,o-ho hydrogen bonds from coordinated water molecules and free l molecules,which leads to a three-dimensional supramolecular architecture. the variable temperature magnetic susceptibilities measurement of compounds 1 and 3 shows the existence of weak antiferromagnetic interactions between the metal centers. the thermogravimetric analyses of the compounds 1-3 are also discussed. © 2013 lingling zheng.