The building block approach to extended solids:: 3,5-pyrazoledicarboxylate coordination compounds of increasing dimensionality

A series of M(II) complexes with the ligand 3,5-pyrazoledicarboxylic acid (H(3)dcp) has been synthesised mainly via hydrothermal reactions and their structures have been characterised. Simple mononuclear [Ni(Hdcp)(H2O)(4)] (1), Na-2([mu-H2O)(2)(H2O)(8)[Ni(Hdcp)(2)(H2O)(2)](2), [M(H(2)dcp)(2)(H2O)(2)].2H(2)O [M = Co (3), Zn (4) and Cu (5)] and dinuclear (Et3NH)(2)[Cu-2(dcp)(2)(H2O)(2)] (9) building blocks have been isolated and subsequently linked into 1-D chains [Mn(Hdcp)(H2O)(2)](infinity) (6), [{Mn(H2O)(4)} {Mn(Hdcp)(2)(H2O)(2)}.4H(2)O](infinity) (7), [Ni-2(Hdcp)(2)(mu-H2O)(2)(H2O)(2)](infinity) (8), [{Ni(H2O)(4)} {Ni-2(dcp)(2)(H2O)(4)}](infinity) (11), or 3-D arrays [{Na-2(mu-H2O} {Cu-2(dcp)(2)}(infinity) (10), [Cu-3(dcp)(2)(H2O)(4)](infinity) (12), utilising novel bridging modes of the H(3)dcp ligand. In the unprecedented 1-D Ni(II) chain 8, rarely reported double aqua-bridges link the Ni(II) ions to form an inter-linked double stranded chain. The magnetic properties of these compounds have been measured and reveal a variety of antiferromagnetic coupling behaviours induced by the ligand bridging modes.