Two polymorphs of Cu(tn)Ni(CN)(4) containing tetracyanonickellate anions with triple bridging function: Preparation and crystallographic characterization

Preparation and crystal structures of two polymorphs of Cu(tn)Ni(CN)(4) (tn = 1,3-diaminopropane) are described. The blue polymorph is orthorhombic (s pace group: Pbca, Z = 4, cell dimensions: a = 9.466(4), b = 12.268(12), c = 19.097(10) Angstrom), the violet one monoclinic (space group: I2/c, Z = 8, cell parameters: a = 16.815(16), b = 9.606(3), c = 21.252(20) Angstrom, be ta = 91.75(5)degrees). In both polymorphs, a rare case of T-type bridging t etracyanonickellate anion is present. The copper atoms are pentacoordinated by one chelate bonded tn molecule and three N atoms from bridging cyano gr oups. The metallacycles prevail in chair conformation. The polymorphs diffe r in the dimensionality of the structure: the blue polymorph exhibits a 2D structure, the violet one a 3D arrangement.