Syntheses, Structures and Luminescent Properties of Two Novel M(II)-Phen-SIP Supramolecular Compounds (M = Co, Ni)

Two metal compounds, [Co(phen)2(H2O)2]·2H2SIP·2H2O 1 and [Ni(phen)3]·2H2SIP·3H2O 2, have been obtained by incorporating 1,10-phenanthroline (phen) and 5-sulfoisophthalic acid monosodium salt (NaH2SIP) ligands under hydrothermal conditions. Meanwhile, the two compounds were characterized by element analysis, IR, XRD, TG-DTA and single-crystal X-ray diffraction. Both 1 and 2 present 3D supramolecular structures via O–H···O hydrogen bond interactions. Luminescent properties for 1 and 2 were also studied. The compound 1 has two fluorescence emission peaks centered at 398 nm attributed to the intraligand emission from the SIP ligand and at 438 nm assigned to the combined interaction of intraligand π*-π transitions of the phen ligand and ligand-to-metal-charge-transfer (LMCT) transitions (λex = 233 nm). The compound 2 shows one emission band centered at 423 nm with a shoulder peak at 434 nm which may be originated from the intraligand π*-π transitions of the phen ligand (λex = 266 nm).