Syntheses, Structures, Luminescent Properties and Photocatalytic Activities of Two Lead(II) Compounds

Two lead(II) compounds, [Pb(qlc)(phen)(2)(NO3)]2 center dot H2O (1) and [Pb(qlc)(2)(phen)]center dot 3H(2)O (2) (Hqlc = quinoline-3-carboxylic acid, phen = 1,10-phenanthroline), were synthesized and characterized by elemental analysis, single-crystal X-ray diffiaction, IR and thermogravimetric analysis. Crystal 1 is of monoclinic, space group C2/c with a = 25.246(5), b = 12.543(3), c = 18.917(4) angstrom, beta = 105.77(3)degrees, V= 5765(2) angstrom(3), Z= 4, C68H46N12O11Pb2, M-r,. = 1621.53, D-c, = 1.886 g.cm(-3), mu(MoK alpha) = 5.912 mm(-1), F(000) = 3152, GOOF = 1.080, the final R = 0.022 and wR = 0.0571 for 4822 observed reflections (I> 2 sigma(I)). Crystal 2 is of triclinic, space group P (1) over bar with a = 8.7883(10), b = 11.7031(13), c = 15.9320(17) angstrom, alpha = 69.9400(10), beta = 78.9780(10), gamma = 79.1650(10), V = 1497.4(3) angstrom(3), Z = 2, C32H26N4O7Pb, M-r = 785.71, Dc = 1.729 g.cm(-3), mu(MoK alpha) = 5.688 mm(-1), F(000) = 756, GOOF = 1.106, the final R = 0.0313 and wR = 0.088 for 5915 observed reflections (I> 20(I)). Single-crystal X-ray diffraction analysis reveals that 1 exhibits a two-dimensional (2D) layer based on pi-pi stacking interactions between phen. Simultaneously, the adjacent 2D layers are assembled via pi-pi stacking interactions between phen and quinoline rings into a 3D supramolecular structure. The zerodimensional structure of 2 is also further extended by pi-pi interactions to form a 2D supramolecular layer. Furthermore, these two compounds exhibit photoluminescence at room temperature in the solid state and their photocatalytic activities have been studied by degradation methylene blue.