Syntheses, crystal structures and fluorescent properties of two new imidazolidino Schiff base compounds

Two new imidazolidino Schiff base compounds, (E)-N-((quinoxalin-2-yl)methylene)-2-(2-(quinoxalin-3-yl)imidazolidin-1-yl)ethanamine 1 and 2-(1-(2-(2-(quinoxalin-3-yl)imidazolidin1-yl)ethyl)imidazolidin-2-yl)quinoxaline 2, have been synthesized and characterized by elemental analysis, H-1 NMR, IR, MS and single-crystal X-ray diffraction. Crystallographic data for 1: C22H21N7, M-r = 383.46, monoclinic, space group P2(1), a = 7.0036(14), b = 6.9151(14), c = 19.701(4) angstrom, beta = 96.57(3)degrees, Z = 2, V = 947.9(3) angstrom(3), D-c =.1.344 g/cm(3), F(000) = 404, mu = 0.085 mm(-1), Flack parameter = 0(2), R = 0.0464 and wR = 0.1055; and those for 2: C24H26N8, M-r = 426.53, triclinic, space group P (1) over bar, a = 9.6680(19), b = 10.334(2), c = 11.389(2) angstrom, alpha= 104.12(3), beta = 102.95(3), gamma = 100.48(3)degrees, Z = 2, V = 1041.2(4) angstrom(3), D-c = 1.361 g/cm(3), F(000) = 452, mu = 0.086 mm, R = 0.0373 and wR = 0.1155. For the two compounds., the five-membered imidazolidine rings all adopt envelope conformation. Moreover, the title compounds show one-dimensional layered and three-dimensional supramolecular chainlike structures, respectively. Fluorescent properties of the two compounds have been investigated in the solid state at room temperature. Compound 1 exhibits strong fluorescence and thus may serve as excellent candidates of green fluorescent materials.