Combination of CuI and tetrahydrothiophene (THT) in MeCN or neat THT produces various phases depending upon experimental conditions. Green luminescent product (CuI)4(THT)2 (1) consists of Cu4I4 cubane units knit into a 3-D network by 2-THT ligands. Yellow luminescent (CuI)10(THT)7(MeCN) (2) contains {[Cu4I4(THT)](2-THT)2(Cu2I2)(2-THT)2[Cu4I4(NCMe)]} "rungs" linked into 1-D ladders by pairs of 2-THT ligands. Two molecular (CuI)4(THT)4 phases were found: 2 orange luminescent 3a and dull yellow luminescent 3b. Triclinic 3b is the more stable phase at 25 °C, but undergoes endothermic transformation to monoclinic 3a at 38 °C. 3a transforms to a triclinic phase (3a') that retains orange emission at −60 °C. Non-emissive (CuI)3(THT)3•MeCN (4) is a 2-D sheet structure in which Cu3(THT)3 rings are linked in trigonal directions by rhomboid Cu2I2 dimer units. The previously reported (CuI)2(THT)4 (5) is a molecular dimer. Temperature and mixing ratio domains for the formation of the CuI-THT phases from MeCN are presented. Luminescence in 1, 2, 3a, and 3b is rationalized based on varying degrees of halide-to-metal charge transfer (XMCT) and metal-centered (MC) behavior. Low temperature spectra reveal reversible changes, including modest red shifts for 1 and 2, and splitting into two excitation/emission band pairs for 3a and 3b.

This investigation is focused on comparing photophysical properties between two series of lanthanide-dicyanoaurate coordination polymers that contain and lack aurophilic interactions, respectively. Luminescence and crystallographic studies have been carried out on five different coordination polymer chain frameworks: the non-aurophilic [(n)Bu4N]2[LnxGd1-x(NO3)4Au(CN)2] (Ln = Eu, Tb; x = 0.01, 0.02, 0.04, 0.08) and[(n)Bu4N]2[EuxTb1-x(NO3)4Au(CN)2] (x = 0.25, 0.5, 0.75), as well as the analogous solid-solutions of aurophilic LnxGd1-x[Au(CN)2]3·3H2O and EuxTb1-x[Au(CN)2]3·3H2O. The single-crystal structures of M[Au(CN)2]3 ·3H2O (M = Eu, Gd) are also reported for comparison. In the aurophilic frameworks the close proximity of gold(I) centers on neighboring chains allows for Au-Au interactions to take place that facilitate energy transfer between lanthanides. Terbium- and europium-doped aurophilic frameworks show energy transfer between one of the lanthanide ions and dicyanoaurate centers as observed via luminescence measurements. In the non-aurophilic frameworks the [(n)Bu4N] cations separate the Au-Au chains, thereby preventing interaction between them, and preventing energy transfer. By preparing the aurophilic EuxTb1-x[Au(CN)2]3·3D2O frameworks, it was shown that the O-H vibrational energy in the hydrated (aurophilic) samples can partially quench the Ln signal.

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New members of the Ln[Au(CN) 2 ] 3 ·3H 2 O and [nBu 4 N] 2 [Ln(NO 3 ) 4 Au(CN) 2 ] series Ln = Ce (CeAu 3 and CeAu respectively) are reported herein where their synthesis, structure and photoluminescence properties are discussed. The first is a 3-D coordination polymer with aurophilic interactions of 3.35 Å and the latter is a 1-D coordination polymer that lacks them. At 293 K both CeAu 3 and CeAu display characteristic Ce III -based emission at λ max = 393 nm (5d→ 2 F J ), however in CeAu 3 Au I -

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Bismuth oxyhalides have recently gained attention for their promise as photocatalysts. Due to their layered structure, these materials present fascinating and highly desirable physicochemical properties including visible light photocatalytic capability and improved charge separation. While bismuth oxyhalides have been rigorously evaluated for the photocatalytic degradation of dyes and many synthesis strategies have been employed to enhance this property, relatively little work has been done to test them against pharmaceuticals and pesticides. These persistent organic pollutants are identified as emerging concerns by the EPA and effective strategies must be developed to combat them. Here, we review recent work directed at characterizing the nature of the interactions between bismuth oxyhalides and persistent organic pollutants using techniques including LC-MS/MS for the determination of photocatalytic degradation intermediates and radical scavenging to determine active species during photocatalytic degradation. The reported investigations indicate that the high activity of bismuth oxyhalides for the breakdown of persistent organic pollutants from water can be largely attributed to the strong oxidizing power of electron holes in the valence band. Unlike conventional catalysts like TiO2, these catalysts can also function in ambient solar conditions. This suggests a much wider potential use for these materials as green catalysts for industrial photocatalytic transformation, particularly in flow chemistry applications.

Evaporative co-crystallization of MCl (M = Na, K, Rb, Cs) with BiOCl in aqueous HCl produces double salts: M x Bi y Cl (x+3y) •zH 2 O. The sodium salt, Na 2 BiCl 5 •5H 2 O (monoclinic P2 1 /c, a = 8.6983(7) Å, b = 21.7779(17) Å, c = 7.1831(6) Å, β= 103.0540(10)°, V = 1325.54(19) Å 3 , Z = 4) is composed of zigzag chains of µ 2-Cl-cis-linked (BiCl 5) n 2nchains. Edge-sharing chains of NaCl n (OH 2) 6−n octahedra (n = 0, 2, 3) are linked through µ 3-Cl to Bi. The potassium salt, K 7 Bi 3 Cl 16 (trigonal R−3c, a = 12.7053(9) Å, b = 12.7053(9) Å, c = 99.794(7) Å, V = 13951(2) Å 3 , Z = 18) contains (Bi 2 Cl 10) 4edge-sharing dimers of octahedra and simple (BiCl 6) 3octahedra. The K + ions are 5-to 8-coordinate and the chlorides are 3-, 4-, or 5-coordinate. The rubidium salt, Rb 3 BiCl 6 •0.5H 2 O (orthorhombic Pnma, a = 12.6778(10) Å, b = 25.326(2) Å, c = 8.1498(7) Å, V = 2616.8(4) Å 3 , Z = 8) contains (BiCl 6) 3octahedra. The Rb + ions are 6-, 8-, and 9-coordinate, and the chlorides are 4-or 5-coordinate. Two cesium salts were formed: Cs 3 BiCl 6 (orthorhombic Pbcm, a = 8.2463(9) Å, b = 12.9980(15) Å, c = 26.481(3) Å, V = 2838.4(6) Å 3 , Z = 8) being comprised of (BiCl 6) 3octahedra, 8-coordinate Cs + , and 3-, 4-, and 5-coordinate Cl −. In Cs 3 Bi 2 Cl 9 (orthorhombic Pnma, a = 18.4615(15) Å, b = 7.5752(6) Å, c = 13.0807(11) Å, V = 1818.87(11) Å 3 , Z = 4) Bi octahedra are linked by µ 2-bridged Cl into edge-sharing Bi 4 squares which form zigzag (Bi 2 Cl 9) n 3nladders. The 12-coordinate Cs + ions bridge the ladders, and the Cl − ions are 5-and 6-coordinate. Four of the double salts are weakly photoluminescent at 78 K, each showing a series of three excitation peaks near 295, 340, and 380 nm and a broad emission near 440 nm.