Self-assembly and characterization of copper 3,4-pyridinedicarboxylate complexes based on a variety of polynuclear hydroxo clustersElectronic supplementary information (ESI) available: Hydrogen bond geometry parameters and hydrogen bonds between two 1-D chains in complex 1, TG curves of complexes 1and 4. CCDC reference numbers 785512–785515. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c0dt00917b

Self-assembly of copper(ii) ion, 3,4-pyridinedicarboxylate (PDC), and 1,10-phenanthroline (phen) under basic conditions at 100 °C affords four PDC linked copper(ii) complexes, [Cu4(μ2-OH)3(μ3-OH)(PDC)(phen)4]n·n(PDC)·11.5nH2O (1), [Cu4(μ2-OH)2(μ3-OH)2(PDC)(phen)4]n·n(PDC)· 11.5nH2O (2), [Cu8(μ2-OH)2(μ3-OH)6(PDC)2(phen)8]·2(PDC)·23H2O (3), and [Cu3.5(μ2-OH)3(PDC)2(phen)]n(4). 1–4are copper hydroxo complexes, and 1, 2and 3co-crystallized from the one-pot reaction. X-ray single crystal diffraction analyses indicate that complexes 1and 2are linkage isomers and contain tetranuclear copper cluster cores with different geometry, and that PDC links the cluster core to form a one-dimensional chain. Complex 3is a discrete step-like octanuclear copper hydroxo cluster complex. The involvement of hydroxo and phen in the coordination makes some coordination sites of PDC idle, which leads to rich hydrogen bonds and π–π interactions in complexes 1, 2and 3. Complex 4contains two types of copper hydroxo cluster cores: chair-like tetranuclear and linear trinuclear units, and the cluster cores are linked by PDC to a double-layer metal–organic framework. Magnetic properties of 1, 3and 4were investigated. The results reveal that complexes 3and 4exhibit strong antiferromagnetic interactions whereas ferromagnetic coupling is predominant for complex 1. The magnetic properties are analyzed in connection with their structures. [ABSTRACT FROM AUTHOR]