![]() |
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ЦЭМИ РАН |
||
Hydrogen-bonded organic frameworks (HOFs) based on the porphyrins with carboxy or nitrogen-bearing substituents have been studied as materials for gases separation, catalysis and proton conductivity. Surprisingly, there are no examples of HOFs constructed from the phosphonate-substituted metal porphyrins although these moieties can form stable multiple H-bonds. Earlier we have shown the possibility to construct supramolecular coordination polymers by the self-assembly of phosphorylated porphyrins. Here we present two crystal structures of nickel(II) porphyrinyl tetraphenylphosphonate (NiTPPP) which form ordered networks through the multiple hydrogen bonds of phosphonate groups between the discrete macrocycle molecules. The crystals 1 and 2 were obtained under solvothermal conditions in the mixture of DMF/H2O. Single crystal X-ray analysis revealed that crystals 1 and 2 both have triclinic P-1 space group and can be described as 2D supramolecular layers of hydrogen-bonded tetradeprotonated [NiTPPP]4-. For charge balance both crystal structures have dimethylamine cations (DMA) formed from the decomposition of the DMF molecules. DMA cations are connected to the porphyrins building blocks by H-bonds as terminal or bridged ligands and additionally stabilize the structures. The difference in structures 1 and 2 consist in the type of layers connections. In structure 1 DMA cations bind 2D layers by bifurcated H-bonds forming a 3D hydrogen-bonded framework, in contrast in 2 - the neighbouring layers are packed by π-π interactions.