Synthesis, crystal structure and properties of a samarium nitrate complex with 2-idobenzoic acid and 2,2'-bipyridine

A complex [Sm(2-1BA)(2)(2,2'-bipy)(NO3)](2) (2-HIBA=2-idobenzoic acid; 2,2'-bipy=2,2'-bipyridine) was synthesized by solvent method and characterized by X-ray single-crystal diffraction. The complex crystallized in triclinic crystal system, P (1) over bar space group, with a=0.97873(3) nm, b=1.28124(3) nm, c=1.29174(3) nm, alpha=108.3740(10)degrees, beta=111.7340(10)degrees, gamma=101.7870(10)degrees. The complex was the centrosymmetric binuclear molecule, in which two Sm3+ ions were connected by four 2-IBA ligands. Two of the 2-IBA ligands were in a bidentate bridging mode and the other two were in a tridentate bridging mode. Sm3+ ion was also coordinated to one chelating NO3- group and one 2,2'-bipy molecule. The 2D supramolecular network formed through weak I center dot center dot center dot I interactions and pi center dot center dot center dot pi stacking interactions. The fluorescent emission peaks at 562, 595, and 642 nm corresponded to the (4)G(5/2)-> F-6(5/2), (4)G(5/2)-> F-6(7/2), and (4)G(5/2)-> F-6(9/2) transitions of Sm3+ ion, respectively.