1D helical or ladder Mn(II) supramolecular isomerism based on imidazo-[4,5-f]-1,10-phenanthroline ligand

Two isomeric Mn(II) complexes, [Mn(IDP)SO4 center dot 2H(2)O] (n) (I) and {[Mn(IDP)SO4 center dot H2O] center dot H2O} (n) (II), have been prepared by solvo-thermal reactions of imidazo-[4,5-f]-1,10-phenanthroline (IDP) ligand with manganese sulfate. The crystal structures of IDP, complexes I and II are characterized by single-crystal X-ray diffusion analyses (CIF files CCDC nos. 988128 (IDP), 988129 (I), and 988130 (II)). The structural analyses show that there are H-bonds and pi-pi stacking interactions resulting in the 3D supramolecular structure for IDP. Complex I exhibits 1D chain-like structure featuring the left- and right-handed helical chains, while in II, the 1D structure is a ladder-like structure. The pi-pi stacking interactions take an important role in the formation of supramolecule structures for complexes HL, I, II due to the large conjugated system of IDP ligand. The IR and UV-Vis absorption spectra of complexes I and II exhibit the difference, but the liquid-state photoluminescence of I and II is similar attributing to the intraligand pi-pi* transition.