A new family of magnetic 2D coordination polymers based on [MV(CN)8]3- (M = Mo, W) and pre-programmed Cu2+ centres

The self-assembly of [M(CN)(8)](3-) (M = Mo, W) anion and polyamine complexes of Cu-II[Cu(tetren)](2+) and [Cu(dien)(H2O)(2)](2+) (tetren = tetraethylenepentamine, dien = diethylenetriamine) in acidic aqueous solution gives (tetrenH(5))(0.8){Cu-4(II)[W-V(CN)(8)](4)}. 7.2H(2)O 1, (tetrenH(5))(0.8){Cu-4(II)[Mo-V(CN)(8)](4)}.7.2H(2)O 2, (dienH(3)){Cu-3(II)[W-V(CN8](3)}.4H(2)O 3 and (dienH(3)){Cu-3(II)[Mo-V(CN)(8)](3)}. 4H(2)O 4 2D coordination polymers. All compounds are structure-related: the crystal structures of isomorphous 1-2 and 3-4, respectively, consist of double-layered cyano-bridged {Cu-II[W-V(CN)(8)](-)}(n) square grid backbones and non-coordinated fully protonated polyamine countercations as well as H2O molecules located between the sheets. The magnetic measurements reveal long range ferromagnetic ordering with sharp phase transitions at T-C in range 28-37 K and coercivity in range 30-225 Oe at liquid helium temperature, T = 4.3 K. (C) 2003 Elsevier Science Ltd. All rights reserved.