Synthesis, Structure, and Photoelectronic Effects of a Uranium−Zinc−Organic Coordination Polymer Containing Infinite Metal Oxide Sheets

Abstract

The hydrothermal reaction of ZnUO2(OAc)4.7H2O with pyridine-2,3-dicarboxylic acid gives rise to a novel uranium-zinc-organic coordination polymer containing infinite U-O-Zn double sheets and organic ligands. Thermal and photoelectrochemical analyses indicate that the coordination polymeric compound not only has a high thermal stability but also exhibits interesting photoelectronic properties.

Water‐Insoluble Ag–U–Organic Assemblies with Photocatalytic Activity

“…Thus, 1 is insensitive to photodecomposition, whereas many silver(i) compounds are unstable under UV irradiation. [52] Elemental analysis calcd (%) for C 22 X-ray crystal structure determination: Yellow blocks of 1 with approximate crystal size of 0.36 0.28 0.20 mm and 2 of 0.23 0.22 0.17 mm were selected, and the single-crystal X-ray data were recorded at 293-(2) K on a Bruker Smart-CCD diffractometer (Mo Ka , l = 0.71073 ). The structures were solved by direct methods (SHELXTL Version 5.10), and refined by full-matrix least-squares techniques on F 2 .…”

“…For irradiation under visible light, the activity difference mainly arises from the difference in visible-light excitation between 1 and 2, as observed in the UV/ Vis absorption spectra. [23] whereas [(ZnO) 2 (UO 2 ) 3 (na) 4 (OAc) 2 ] (Hna = nicotinic acid), built up from inorganic U-O-Zn-clustered double sheets, [22] and the well-known thermal catalysts UO 3 and U 3 O 8 , in which all U À O species are crystallized together, [50] are inactive under identical conditions, since they can hardly form transition complexes with RhB due to the poor accessibility of their U centers to RhB molecules. Therefore, our compounds, especially 1, are a unique type of coordination polymers with uranyl units that exhibit high photocatalytic activity for dye degradation because of the accessibility of their U centers, which can be photoexcited by UV or visible light.…”

“…[6,22] In particular, the discovery of photocatalytic activity of a 3D U-containing solid compound [23] prompted us to synthesize water-insoluble organic-inorganic uranyl materials with improved photocatalytic performance. Here we describe two bimetallic 2D assemblies, [Ag(bipy)(UO 2 ) 2 (bdc) 1.5 ] (1; bipy = 2,2'-bipyridyl, bdc = 1,4-benzenedicarboxylate) and [Ag 2 (phen) 2 UO 2 (btec)] (2; phen = 1,10-phenanthroline; btec = 1,2,4,5-benzenetetracarboxylate), both of which are water-insoluble and more active than nanosized TiO 2 (P-25) for the degradation of rhodamine B, a cationic N-containing dye which is generally recognized as being difficult to degrade.…”

An Unexpected Photoelectronic Effect from [Co(en)3]2(Zr2F12)(SiF6)⋅4 H2O, a Compound Containing an H‐Bonded Assembly of Discrete [Co(en)3]3+, (Zr2F12)4−, and (SiF6)2− Ions

“…The current reaches a steady-state value in approximately 300 s. The trace shows that an anodic photocurrent of about 2.6 mA is generated at a constant applied voltage of 0.4 V versus SCE, which is much higher than that of (ZnO) 2 (UO 2 ) 3 (NA) 4 (OAC) 2 (0.2 mA) under the same measurement conditions. [16] In contrast to conventional oxide semiconductors, [17] the current density of compound 1 is very low. However, the lower current density, in combination with its lower electrical conductivity (< 10 À5 S cm À1 ), suggests that compound 1 might contain a controlled carrier density [18] similar to that of (ZnO) 2 (UO 2 ) 3 (NA) 4 (OAC) 2 .…”

A Rare (3,4)‐Connected Chalcogenide Superlattice and Its Photoelectric Effect

“…The I-V characteristic of the SnO 2 (F-doped)/CMF-4/nafion electrode shows increased photocurrent generation with increasing anodic potential, and this suggests that the CMF-4 film shows n-type semiconductor behavior. [19] The mechanism of photocurrent generation can be explained as follows: Photoinduced charge separation in the CMF-4 film is the primary step, followed by hole transfer to the SO 3 2À anion in the solution and electron transfer to the collecting electrode. A steady photocurrent is thus observed in this photoelectrochemical cell.…”