Heterometallic coordination polymers incorporating dipyrrin based heteroleptic copper and cobalt complexes: to Ag-π or not?Electronic supplementary information (ESI) available: comparison of experimental and simulated X-ray diffraction powder patterns for 5 and 6. CCDC 868785-868791 for 1-2 and 5-9. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2dt30549f

Using ligands based on either an acetylacetonate or a dipyrrin moiety appended with pyridyl groups, a series of novel heteroleptic copper( ii ) and cobalt( iii ) complexes combining both chelate units such as (acacpy 2 )Cu(dpm-py) and (acacpy 2 )Co(dpm-py) 2 (acacpy 2 = 1,3-bis(4-pyridyl)-1,3-propanedionate; dpm-py = 5-(4-pyridyl)dipyrrin) have been prepared and fully characterized. These two complexes were obtained upon reaction of dpm-py with the (acacpy 2 )M homoleptic species (M = Cu( ii ), Co( ii )). In the solid state, the (acacpy 2 )Cu(dpm-py) complex behaves as a self-complementary metallatecton and leads to the formation of a 1D coordination polymer (CP) through the coordination of a peripheral pyridyl group to the copper centre. Contrastingly, the octahedral (acacpy 2 )Co(dpm-py) 2 complex featuring a coordinatively saturated Co( iii ) centre crystallizes as an isolated mononuclear species. In order to generate heterometallic CPs, both complexes have been used as metallatectons upon their combination with different silver( i ) salts. Upon reaction of (acacpy 2 )Cu(dpm-py) with Ag(BF 4 ) or Ag(TfO), 2- and 3-D heterometallic networks were obtained, respectively. In both cases, sheet type arrangements resulting from the binding of Ag + cations by three peripheral pyridyl groups were observed. These 2D sheets are further interconnected through Ag-π interactions with the pyrrolic rings. Under the same conditions, the combination of (acacpy 2 )Co(dpm-py) 2 with Ag(TfO) leads to two networks differing by their connectivity patterns and dimensionality. Interestingly, whereas no Ag-π interactions were observed for the 2D network, a combination of coordination bonding with the pyridyl moieties and Ag-π interactions was detected for the 1D architecture. Heteroleptic acac and dipyrrin based Cu( ii ) and Co( iii ) complexes form, with Ag( i ) salts, heterometallic networks resulting from coordination of the Ag( i ) cation to the peripheral pyridyl groups and Ag-π interactions.