Bulk Assembly of Organic Metal Halide Nanoribbons

Organic metal halide hybrids with low-dimensional structures at the molecular level have received great attention recently for their exceptional structural tunability and unique photophysical properties. Here we report for the first time the synthesis and characterization of a one-dimensional (1D) organic metal halide hybrid material, which contains metal halide nanoribbons with a width of three octahedral units. It is found that this material with a chemical formula C$_8$H$_{28}$N$_5$Pb$_3$Cl$_{11}$ shows a dual emission with a photoluminescence quantum efficiency (PLQE) of around 25% under ultraviolet (UV) light irradiation. Photophysical studies and density functional theory (DFT) calculations suggest the coexisting of delocalized free excitons and localized self-trapped excitons in metal halide nanoribbons leading to the dual emission. This work shows once again the exceptional tunability of organic metal halide hybrids that bridge between molecular systems with localized states and crystalline ones with electronic bands.Comment: 6 pages, 4 figures, plus supporting informatio

Surface Effects on Anisotropic Photoluminescence in One-Dimensional Organic Metal Halide Hybrids

One-dimensional (1D) organic metal halide hybrids exhibit strongly anisotropic optical properties, highly efficient light emission, and large Stokes shift, holding promises for novel photodetection and lighting applications. However, the fundamental mechanisms governing their unique optical properties and in particular the impacts of surface effects are not understood. Here, we investigate 1D C4N2H14PbBr4 by polarization-dependent time-averaged and time-resolved photoluminescence (TRPL) spectroscopy, as a function of photoexcitation energy. Surprisingly, we find that the emission under photoexcitation polarized parallel to the 1D metal halide chains can be either stronger or weaker than that under perpendicular polarization, depending on the excitation energy. We attribute the excitation-energy-dependent anisotropic emission to fast surface recombination, supported by first-principles calculations of optical absorption in this material. The fast surface recombination is directly confirmed by TRPL measurements, when the excitation is polarized parallel to the chains. Our comprehensive studies provide a more complete picture for a deeper understanding of the optical anisotropy in 1D organic metal halide hybrids

Reactivity of Phosphonothioamidates with Acid Chlorides and Primary Amines: Synthesis and Conformational Study of N-Acylated Phosphonothioamidates and Phosphonoamidines

<div><p></p><p>Various <i>N</i>-acyl phosphonothioamidate derivatives, <b>2</b>, were obtained from <i>N</i>-acylation of phosphonothioamidates, <b>1</b>, with different acid chlorides. Phosphonoamidines, <b>3</b>, were prepared in high yields by reacting phosphonothioamidates, <b>1</b>, with primary amines at room temperature, ro short reaction periods. All compounds were characterized on the basis of IR and NMR spectroscopy (¹H, ¹³C, ¹⁹F and ³¹P) and in some cases by elemental analysis and calculations using Density Functional Theory (DFT)-B3LYP// 3-21G+** and evolution study by ³¹P-NMR and ¹⁹F-NMR spectroscopy using an external lock with D₂O. </p><p></p><p></p></div

Synthesis and structural Studies of phosphonothioamidates

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One-dimensional organic metal halide nanoribbons with dual emission

Organic metal halide hybrids with low-dimensional structures at the molecular level have received great attention recently for their exceptional structural tunability and unique photophysical properties. Here we report for the first time the synthesis and characterization of a one-dimensional (1D) organic metal halide hybrid, which contains metal halide nanoribbons with a width of three octahedral units. It is found that this material with a chemical formula C8H28N5Pb3Cl11 shows a dual emission with a photoluminescence quantum efficiency (PLQE) of around 25%. Photophysical studies and density functional theory (DFT) calculations suggest the coexisting of delocalized free excitons and localized self-trapped excitons in metal halide nanoribbons leading to the dual emission