Structural and Magnetic Properties of Cu[C(CN)3]2 and Mn[C(CN)3]2

Single-crystal X-ray structure analyses and the measurements of static magnetic susceptibility and ESR have been performed for the title compounds. Crystal data: for Cu[C(CN) 3 ] 2, space group Pmna, a = 7.212(5) Å, b = 5.452(7) Å, c = 10.696(7) Å, and Z = 2; for Mn[C(CN) 3 ] 2, space group Pmna, a = 7.742(5) Å, b = 5.411(6) Å, c = 10.561(6) Å, and Z = 2. Both salts are essentially isostructural. The Cu atoms are bridged by two [C(CN) 3 ] - anions to form an infinite double chain structure, in which Cu has a square planar coordination ( d Cu - N = 1.986(6) Å). The third CN end of the anion is weakly coordinated to the adjacent Cu chain ( d Cu - N = 2.47(1) Å), making a three-dimensional network. The crystal is composed of two such interwoven networks. In the Mn complex, the third Mn−N distance (2.256(6) Å) is as short as the equatorial coordinations (2.236(4) Å), so that Mn is coordinated octahedrally. These compounds exhibit paramagnetic behavior following the Curie−Weiss law with Weiss temperatures −1.4 and −9 K, respectively, and the Mn complex undergoes an antiferromagnetic transition at T N = 5 K.