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We describe herein a three-dimensional Cu(II) based metal−organic framework, copper hydroxide 2,6-naphthalenedisulfonate, Cu3(OH)4[C10H6(SO3)2]. The compound contains embedded positively charged 2-D copper oxide layers. This higher dimensionality of inorganic connectivity leads to far greater thermal stability (375 °C vs 245 °C) over our previously reported three-dimensional metal−organic framework containing embedded 1-D cuprate chains. Single crystal data for this material are as follows: FW = 544.92, monoclinic, space group P21/c, a = 13.549(5) Å, b = 5.503(2) Å, c = 9.512(4) Å, β = 90.031(6)°, V = 709.2(5) Å3, Dc = 2.552 g·cm−3, and Z = 4. The structure, crystallinity, morphology, and properties of the material are discussed. The magnetic susceptibility exhibits a broad maximum centered at 80 K, indicative of low-dimensional antiferromagnetic interactions. Control of inorganic dimensionality embedded within an MOF is an often overlooked yet key feature in determining the stability and important properties of MOFs such as adsorption, conductivity, and magnetism. A three-dimensional Cu(II) based metal−organic framework, copper hydroxide 2,6-naphthalenedisulfonate, is described. The compound contains embedded cationic 2-D copper oxide layers, with greater thermal stability over our previously reported three-dimensional MOF containing embedded cationic 1-D cuprate chains. Control of inorganic dimensionality embedded within an MOF is an often overlooked yet key feature in determining important properties of MOFs such as adsorption, conductivity, and magnetism. [ABSTRACT FROM AUTHOR]

A three-dimensional Cu(II) metal-organic framework, copper hydroxide p-pyridinecarboxylate hydrate, [Cu(OH)(C5H4NCO2)·H2O], was synthesized by hydrothermally reacting copper nitrate with p-pyridinecarboxylic acid. The crystals were suitable for single-crystal X-ray diffraction analysis, which showed that the Cu(II) centers adopt a slightly distorted square pyramidal geometry. They coordinate to both the pyridyl and carboxylate functionalities of the pyridinecarboxylate bridging ligands. Infinite copper oxide chains run through the structure and are connected by p-pyridinecarboxylate (p-PyC) ligands. Crystal data: monoclinic, space group P21/n, a = 3.5521(2) Å, b = 15.8665(11) Å, c = 12.9977(9) Å, β = 95.285(2)°, and Z = 4. Thermogravimetric analysis (TGA) revealed that the guest H2O molecules in the channels may be removed, and the material is stable to ca. 245 °C. Magnetic measurements indicated the material has one-dimensional (1D) antiferromagnetic ordering within the Cu2+ chains with a Néel temperature of ca. 51 K. Data fitting to the Bonner-Fisher model yielded a coupling constant, J, of -7.3 cm-1 and g factor of 2.15. The Curie tail below 20 K is due to a small amount of paramagnetic impurities, calculated to be ∼0.2% in concentration. Further characterization of crystallinity and morphology are discussed, including powder X-ray diffraction (PXRD), elemental analysis, and optical microscopy. [ABSTRACT FROM AUTHOR]

We report the solvothermal synthesis and characterization of a series of layered lead phenylphosphonates. The crystals were suitable for single crystal X-ray diffraction data, and the two new structures we denote BING-6 [SUNY at Binghamton, Structure No. 6, Pb(PO[sub 3]C[sub 6]H[sub 5])·0.25C[sub 5]H[sub 5]N, triclinic space group P&1oline;, Z = 2, a = 7.0770(4) Å, b = 9.3113(6) Å, c = 14.6785(9) Å, α = 80.456(1)°, β = 78.023(1)°, γ = 73.265(1)°] and BING-9 [Pb(PO[sub 3]-HC[sub 6]H[sub 5])(PO[sub 3]HC[sub 6]H[sub 4]CH[sub 3]), monoclinic space group C2/c, Z = 4, a = 32.663(8) Å b = 5.6220(13) Å, c = 8.3307(19) Å, β = 101.419(4)°]. The third structure, a polytype of BING-9, was previously known only from powder X-ray diffraction methods and is denoted 3 [Pb(PO[sub 3]HC[sub 6]H[sub 5])[sub 2], monoclinic space group C2/c, Z = 4, a = 31.681(6) Å, b = 5.5639(11) Å, c = 8.2515(16) Å, β = 101.814(4)°]. All three structures possess Pb(II) and P centres connected by doubly and triply bridging oxygens. The phenyl groups cap and separate the charge-neutral layers. The phosphonates of BING-6 are nonprotonated, and the structure therefore has a Pb/P ratio of 1:1. Neutral, partially disordered pyridine solvent molecules also reside in the interlamellar space, increasing the layer to layer distance. BING-9 and 3 are polytypes and contain singly protonated phosphonates, for a Pb/P ratio of 1:2. Further characterization methods are discussed, including powder X-ray diffraction, in-situ variable temperature powder X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. Related work in the Ge, Sn, and Mn systems is also discussed. These low-dimensional materials may be useful intercalation compounds for ion-exchange or sensors applications. [ABSTRACT FROM AUTHOR]

Focuses on the development of Pb[sub 3]F[sub 5]NO[sub 3], a cationic layered material for anion-exchange. Structures of layered material; Factors affecting the stability of material temperature; Growth of anionic clusters within the void space of cationic material.

Examines the photophysical and photochemical properties of W(O) and Re(I) carbonyl complexes. Use of special redox-active features to develop electrochemical sensors; Focus on homonuclear ferrocenes different organic spacers; Photophysical and photochemical properties of polypyridyl d[sup 6]-metal(W[sup 0] and Re[sup I]) carbonyl complexes.

On the path toward the design of Li-ion batteries with increased energy densities, efforts are focused on the development of positive electrodes that can maximize the voltage of the full cell. However, the development of novel materials that operate at high voltage, while also showing high efficiency and meeting strict safety standards, is an ongoing challenge. LiCoPO4 is being explored as a possible candidate, as the Co2+/3+ redox couple operates at 4.8 V versus Li+/Li0. The presence of phosphate groups is typically expected to stabilize the compound against oxygen loss, yet the changes in Co-O bonding upon Li extraction have not been ascertained. In addition, LiCoPO4 is riddled with problems relating to poor transport and strain in the crystal structure of the delithiated phase, which handicap its use as a high-voltage electrode. In this work, substituting ions to generate Li1.025Co0.84Fe0.10Cr0.05Si0.01(PO4)1.025 is found to stabilize both the electronic structure and crystal structure and, therefore, substantially improve the ability to fully utilize the redox capacity of the material. A thorough study by spectroscopic tools, combined with computations of the electronic structure, was used to probe changes in chemical bonding. The measurements revealed the existence of redox gradients between surface and bulk that are common in other materials that react at high potential. The study offers a comprehensive understanding of the fundamental reactions in LiCoPO4-type frameworks, while further demonstrating that ion substitution is an effective tool for improving their performance. [ABSTRACT FROM AUTHOR]