Crystal structure of the poly[(1,10-phenanthroline-κ² <i>N</i>,<i>N</i>′)(μ₃-carboxylatophenoxyacetato-κ⁴ <i>O,O</i>′:<i>O</i>′′;<i>O</i>′′′)lead(II)] monohydrate, C₂₁H₁₆N₂O₆Pb

Abstract C21H16N2O6Pb, monoclinic, P21/c (no. 14), a = 8.3116(17) Å, b = 19.439(4) Å, c = 11.437(2) Å, β = 98.11(3)°, V = 1829.4(6) Å3, Z = 4, R gt (F) = 0.0485, wR ref (F 2 ) = 0.0895, T = 293(2) K.</jats:p

Photoluminescence and Electroluminescence from a Hybrid of Lumogen Red in Nanoporous-Silica

In this paper white electroluminescence from a lumogen red-doped nanoporous silica matrix is presented. The matrix was prepared using a sol–gel process, and lumogen red—a perylene derivative—was doped at a number of concentrations. The photoluminescence and electroluminescence of the lumogen red-doped nanoporous-silica composite were investigated in detail. The structures, surface morphology, and optical properties of the nanoporous silica composites were investigated. The average pore size of the nanoporous-silica matrix was ∼5 nm. The absorption spectra of the lumogen red in the nanoporous-silica matrix were broader than those from solution specimens. The photoluminescence of the lumogen red-doped nanoporous-silica matrix depended strongly on the excitation wavelengths. When excited at relatively longer wavelengths, e.g., 467 nm, the emissions peaked at constant positions (∼608 nm) for all cases, except a small shift to the red from its solution 601 nm. However, if excited at a shorter wavelength in the range of 200–400 nm, additional blue emissions were observed, which were particularly strong and suggested defect centers of the nanoporous-silica matrix. The electroluminescence from a single-layered sandwich device consisting of the lumogen red-doped nanoporous-silica was interesting. When driving with an AC electric field, electroluminescence spectra covered a whole spectral range, consisting of the red emission from lumogen red and the blue and green emission from the nanoporous silica matrix. In this way, we actually achieved a white electroluminescence from this hybrid organic and silica device with a color coordinate, CIE [x, y] = [0.30, 0.35] at a driving electric field of 3.0 × 106 V/cm. This was a first attempt to investigate electroluminescence from an organic dye-doped nanoporous silica matrix.</jats:p

Mesogenic complementary absorbing dyads based on porphyrin and perylene units

Five novel dyads, consisting of a tetraphenylporphyrine unit connected to a perylene monoimide diester unit via a flexible bridge -CONH-(CH[Formula: see text]- (n [Formula: see text] 4, 6, 8, 10 and 12), have been synthesized. Their structures were characterized by [Formula: see text]C and [Formula: see text]H nuclear magnetic resonance spectroscopy, infrared spectroscopy, mass spectrometry and elemental analysis. The UV-vis absorption spectra revealed these dyads have broad optical absorption in the ultraviolet and visible regions due to the complementary absorption of the two units. The differential scanning calorimetry traces and polarized optical microscopy textures showed all these dyads have columnar liquid crystal phases. Cyclic voltammetry revealed the highest occupied molecular orbitals of the dyads located on the porphyrin units, and the lowest unoccupied molecular orbitals located on the perylene units. In addition, these results were in agreement with that of the theoretical modeling. When excited at 423 or 473 nm, the photoluminescent emission spectra showed that the degree of fluorescence quenching of porphyrin units increased as the spacers became shorter. This quenching was ascribed to intramolecular photoinduced electron transfer, which also induced the dyad molecules to form the charge-separated states. The charge-separated molecules were further confirmed by the photocurrent response curves. These behaviors of broad absorption of the ultraviolet-visible light, yielding the charge-separated states of the molecules when excited and the formation of columnar liquid crystal phase made these dyads candidates for single-component photovoltaic active materials. </jats:p