Gas Sorption, Second-Order Nonlinear Optics, and Luminescence Properties of a Series of Lanthanide-Organic Frameworks Based on Nanosized Tris((4-carboxyl)phenylduryl)amine Ligand

By controlling the pH value of the reaction system, two sets of lanthanide (Ln)-tris((4-carboxyl)-phenylduryl)amine (Ln = Ce, Pr, Nd, Sm) frameworks have been generated. Four isostructural noninterpenetrating frameworks (FIR-8 to FIR-11) are constructed from rod-shaped secondary building units and four other isostructural frameworks (FIR-12 to FIR-15) based on single Ln nodes are described as 8-fold interpenetrating dia-type nets. Gas sorption measurements for FIR-8 give a Langmuir surface area of 633.8 m(2).g(-1) and a H-2 uptake of 165.2 cm(3).g(-1) at 77 K and 1 atm. However, FIR-12 with smaller pores can hardly adsorb any N-2 and H-2. Because both FIR-8 and FIR-12 crystallize in acentric space group, the second-harmonic generation (SHG) measurements indicate that both of them display strong powder SHG efficiencies, which are approximately 8 and 3 times as strong as that of a potassium dihydrogen phosphate powder. In addition, the fluorescent emissions of all compounds in the solid state are also investigated in detail.