Metal Iodates Research Articles

Iodine-Rich Biocidal Reactive Materials

ABSTRACTThe objectives of this work are to prepare and characterize iodine-rich thermites and reactive materials for potential application in bio-agent defeat. Iodine-rich compositions were prepared using metal iodate oxidizers in combination with aluminum fuel. Higher iodine contents were achieved using iodine-rich additives, tetraiodoethylene and tin tetraiodide. Reactivity during rapid combustion was evaluated for both nanoscale and micron-scale materials. The nanoscale materials were evaluated directly using a spark-initiated pan dent test. The micron-scale materials were mixed with 50% of nano Al/MoO3 and also evaluated with the pan dent test. The results for the mixed material were shown to fit well to a linear combination of the expected dent for each component, based on a rapid reaction. Results of the pan dent test were used to down-select micron thermites for further testing. Bismuth iodate was synthesized by precipitation from nitric acid solutions. The average particle size was controlled by the addition rate, and sizes included 95 nm (amorphous structure), and 330 nm and 3 micron (both crystalline). Additional sizes were produced by ball milling the 3 micron material, giving 1 micron and 350 nm sizes. Fluoropolymers were included in some compositions to provide additional biocidal products, namely HF, that could be produced from reaction of AlF3 product with water.

K4TM4(V2O7)2(IO3)4(H2O) (TM = Zn, Ni, Co): a series of quinary mixed metal–vanadium(v)–iodates

Systematic explorations of new compounds in the divalent transition metal–vanadium(V)–iodate system by hydrothermal reactions led to three quinary mixed metal iodates, namely, K4TM4(V2O7)2(IO3)4(H2O) (TM = Zn, Ni, Co). They represent the first examples of quinary mixed metal vanadium iodates. The structures of K4TM4(V2O7)2(IO3)4(H2O) (TM = Zn, Ni, Co) are quite unusual and consist of sandwich-like double layers of 1∞[TM4(V2O7)2(IO3)4(H2O)]4− that are separated by K+ cations. The interconnection of TMO6 units via tridentate bridging IO3− groups resulted in a 2D sheet parallel to the ab-plane. Two such sheets are bridged by V2O7 units into a unique sandwich-like double layer. V2O7 units are observed in iodates for the first time. Thermal stability and optical properties as well as magnetic properties for the Co and Ni phases were studied.

Syntheses, crystal structures and magnetic properties of three new silver manganese(ii) or manganese(iii) mixed metal iodates

Systematic explorations of new compounds in the unexplored Ag+–Mn2+/Mn3+–iodate system led to three new silver Mn2+ (or Mn3+)-mixed metal iodates, namely, AgMn(IO3)3, AgMn(IO3)4 and Ag3Mn(IO3)6. These compounds feature the same building units of MnO6 octahedron and IO3, but the different coordination modes of the iodate groups in these compounds led to three different types of anionic structures ranging from a zero-dimensional (0D) cluster to a two-dimensional (2D) layer. Interestingly, the dimensions of the anionic structure decrease with an increase in the IO3/Mn molar ratio in the formula. AgMn(IO3)3 exhibits a 2D [Mn2(IO3)6]n2n− anionic layer in which the Mn2O2 rings are further decorated by terminal iodates and interconnected by bidentate and tridentate bridging iodate groups. AgMn(IO3)4 displays a one-dimensional (1D) [Mn(IO3)4]nn− anionic chain in which each pair of MnO6 octahedra is bridged by a pair of IO3 groups, and within the chain each manganese center is also attached with two terminal iodate groups from both sides of the chain. Ag3Mn(IO3)6 features isolated 0D [Mn(IO3)6]3− anions. The Ag+ cations in all three compounds act as spacers between these anions. Optical, thermal stability and magnetic susceptibility measurements for AgMn(IO3)3 and AgMn(IO3)4 have also been performed.

Study of Optical Property of Gel Grown Mercuric Iodate Crystals

Mercuric Iodate Crystals were grown by a simple gel technique using diffusion method. The optimum growth conditions were established for the growth of these crystals by changing various parameters such as pH of the gel solution, gel concentration, gel setting time, concentrations of reactants etc. The grown Mercuric Iodate crystals were spherical in shape. These crystals were opaque. The crystals were characterized using UV- VIS Specrophotometrry. .Keywords. Gel technique, mercuric iodate crystals, UV-VIS Specrophotometrry. I. Introduction: A variety of crystals required for the purpose of research and application can be grown in silica gels. The gel medium prevents turbulence and being chemically inert, it provides a three-dimensional crucible which permits the reagents to diffuse at a desirable controlled rate. Its softness and uniform nature of constraining forces that it exerts upon the growing crystals encourages orderly growth. The growth of single crystals in gel at an ambient temperature, which are sparingly soluble in water, is a fascinating alternative to the techniques involving high temperature and expensive equipments. During the last few years, successful application of gel growth technique has been demonstrated by the preparation of single crystals of alkaline earth metal iodate. The gel growth technique appeared quite attractive for growing crystals of such compounds on account of its unique advantages in terms of crystals produced and the simplicity of process. In the present work, crystals of mercuric iodate were grown by gel technique using diffusion method. Optimum growth conditions for crystals were determined. Optimum conditions were established by varying various parameters. II. Materials and Method Test tubes were used as crystallizing vessels. The silica gel was used as a growth media. Gel was prepared from aqueous solution of sodium meta silicate. The gel was acidified by acetic acid. The chemicals used for growth of single crystals of mercuric iodate were CH3COOH; Na2SiO3.5H2O; KIO3, NaIO3; Hg(NO3)2. All chemicals were of AR grade. A series of experiments using different pH values for the gel and the different concentrations for reactants were carried out. Different molar masses were tried to determine the optimum growth conditions. Out of the two reactants, Hg(NO3)2 was incorporated in gel and KIO3 was used as the supernatant over the set gel. These experiments yield spherulitic crystals of Hg(IO3)2 of few mm size. Experiments were also carried out by interchanging the position of reactants. These experiments do not yield any crystals at all. Hg(NO3)2 having different concentrations was incorporated into the gel. This solution was then transferred to borosil glass tube of diameter 2.5 cm and 25 cm in height. The mouth of the tube was covered by cotton plug. After setting of the gel, it was left for aging for different periods of time. Another reactant having different concentrations was then added as supernatant over the set gel. Experiments were carried out by changing different concentrations of the reactants. The chemical reaction inside the gel can be expressed as X(NO3)2 + 2YIO3 → X(IO3)2 + 2YNO3 Where X = Hg and Y = K or Na

Structures and properties of functional metal iodates

Metal iodates with a lone-pair containing I(V) that is in an asymmetric coordination geometry can form a diversity of unusual structures and many of them are promising new second homonic generation (SHG) materials. They exhibit wide transparency wavelength regions, large SHG coefficients and high optical-damage thresholds as well as moderately high thermal stability. In this paper, the structures and properties of the metal iodates are reviewed. The combination of d0 transition-metal cations with the iodate groups afforded a large number of metal iodates, with cations covering alkali metal, alkaline earth and lanthanide elements. Many of them are noncentrosymmetric (NCS) and display excellent SHG properties due to the additive effects of polarizations from both types of the asymmetric units. Some lanthanide iodates are able to emit strong luminescence in the visible or near-IR regions. The use of transition metal ions with d n (n ≠ 0) electronic configuration into iodate systems can also induce the formation of NCS compounds when the lone pairs of the iodate groups are properly aligned. The d n transition metal cations are normally octahedrally coordinated or in a square-planar coordination geometry. Furthermore, the combination of two different types of lone-pair-containing cations is also an effective strategy to design new SHG materials.

Explorations of New Second-Order Nonlinear Optical Materials in the KI-MII -IV-O Systems

Explorations of new second-order nonlinear optical (NLO) materials in the K(I)-M(II) -I(V)-O systems led to four novel mixed metal iodates, namely, K(2)M(IO(3))(4)(H(2)O)(2) (M = Mn, Co, Zn, Mg). The four compounds are isostructural and crystallize in space group I2 which is in the chiral and polar crystal class 2. Their structure features zero-dimensional {M(IO(3))(4)(H(2)O)(2)}(2-) anions that are separated by K(+) cations. The M(II) centers are ligated by two aqua ligands in trans fashion and four monodentate iodate anions. The K(+) cation is eight-coordinated by two iodate anions in bidentate chelating fashion and four other iodates in a unidentate fashion. Second harmonic generation (SHG) measurements indicate that K(2)Zn(IO(3))(4)(H(2)O)(2) and K(2)Mg(IO(3))(4)(H(2)O)(2) display moderate SHG responses that are approximately 2.3 and 1.4 times of KH(2)PO(4) (KDP), respectively, and they are also phase-matchable. The SHG response of K(2)Co(IO(3))(4)(H(2)O)(2) is much weaker (about 0.3 x KDP), and no obvious SHG signal was detected for K(2)Mn(IO(3))(4)(H(2)O)(2). Results of optical property calculations for the Zn and Mg phases revealed SHG responses of approximately 5.3 and 4.7 times of KDP, respectively, the order of Zn > Mg is in good agreement with the experiment data.

Hydrothermal synthesis and structure characterization of the first organically templated metal iodates

The first organically templated molybdenum iodates (C 5H 6N) 2Mo 2O 5(IO 3) 4(H 2O) 2 ( 1), (C 10H 8N 2)[MoO 2(IO 3) 3] · H 3O ( 2), and uranium iodate (C 5H 5N) 2[(UO 2)(IO 3) 3](IO 3) ( 3), have been successfully synthesized under mild hydrothermal conditions. Compound 1 is simple zero-dimensional units consisting of [(Mo 2O 5(IO 3) 4)] 2− anions, which can be described as a tetranuclear unit hanged on either side by two [IO 3] groups. The [Mo 2O 5(IO 3) 4] 2− anions are in a close connection through the water molecules and protonated pyridine cations, via hydrogen bonds and intermolecular actions. Compound 2 is built up from [MoO 6] octahedra and [IO 3] pyramids to two-dimensional layers, in which 4,4′-bipy molecules and water cations are located, forming strong hydrogen bonds with the inorganic framework, leading to pseudo three-dimensional structure. Compound 3 is one-dimensional ribbons containing {[(UO 2)(IO 3) 3](IO 3)} 2− anions and charge neutrality is achieved by the protonated 4,4′-bipy cations, which reside between two ribbons, forming hydrogen bonds with the inorganic framework and resulting in pseudo two-dimensional structure. Crystal data are as follows: (C 5H 6N) 2Mo 2O 5(IO 3) 4(H 2O) 2 ( 1), orthorhombic, Pnma, a = 24.097(5) Å, b = 13.532(3) Å, c = 7.836(16) Å, Z = 4, V = 2555.2(9) Å 3; (C 10H 8N 2)[MoO 2(IO 3) 3] · H 3O ( 2), monoclinic, C2/ c, a = 24.176(5) Å, b = 10.751(2) Å, c = 7.5074(15) Å, β = 107.44(3)°, Z = 8, V = 1861.6(6) Å 3; (C 5H 5N) 2[(UO 2)(IO 3) 3](IO 3) ( 3), monoclinic, P2 1/ n, a = 14.430(3) Å, b = 7.3459(15) Å, c = 19.811(4) Å, β = 106.70(3)°, Z = 4, V = 2011.3(7) Å 3.

Square‐Planar Noble Metal Iodate [M(IO3)4]n‐ (M = PdII, AuIII; n = 2, 1) Anions and Their Ability to Form Polar and Centrosymmetric Architectures.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Synthesis and Structure of In(IO3)3 and Vibrational Spectroscopy of M(IO3)3 (M: Al, Ga, In).

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Square‐Planar Noble Metal Iodate [M(IO3)4]n– (M = PdII, AuIII; n = 2, 1) Anions and Their Ability to Form Polar and Centrosymmetric Architectures

AbstractK+ salts of the square‐planar noble metal iodate [M(IO3)4]n– (M = PdII, AuIII; n = 2, 1) anions have been prepared under mild hydrothermal conditions, and the structures elucidated to demonstrate that while both are highly polar anions, polar and centrosymmetric extended architectures can form using these building units. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Synthesis and structure of In(IO 3) 3 and vibrational spectroscopy of M(IO 3) 3 ( M=Al, Ga, In)

The reaction of Al, Ga, or In metals and H 5IO 6 in aqueous media at 180 °C leads to the formation of Al(IO 3) 3, Ga(IO 3) 3, or In(IO 3) 3, respectively. Single-crystal X-ray diffraction experiments have shown In(IO 3) 3 contains the Te 4O 9-type structure, while both Al(IO 3) 3 and Ga(IO 3) 3 are known to exhibit the polar Fe(IO 3) 3-type structure. Crystallographic data for In(IO 3) 3, trigonal, space group R 3 ¯ , a=9.7482(4) Å, c=14.1374(6) Å, V=1163.45(8) Z=6, R( F)=1.38% for 41 parameters with 644 reflections with I>2 σ( I). All three iodate structures contain group 13 metal cations in a distorted octahedral coordination environment. M(IO 3) 3 ( M=Al, Ga) contain a three-dimensional network formed by the bridging of Al 3+ or Ga 3+ cations by iodate anions. With In(IO 3) 3, iodate anions bridge In 3+ cations in two-dimensional layers. Both materials contain distorted octahedral holes in their structures formed by terminal oxygen atoms from the iodate anions. The Raman spectra have been collected for these metal iodates; In(IO 3) 3 was found to display a distinctively different vibrational profile than Al(IO 3) 3 or Ga(IO 3) 3. Hence, the Raman profile can be used as a rapid diagnostic tool to discern between the different structural motifs.

Crystal structure of M(IO3)2 metal iodates, twinned bypseudo-merohedry, with MII: MgII, MnII, CoII, NiII and ZnII

Abstract The non-centrosymmetric materials Zn(IO3)2, Mn(IO3)2, Co(IO3)2, Mg(IO3)2 and β-Ni(IO3)2 have been synthesised by evaporation of nitric acid solutions of metal salts and lithium iodate. All these compounds are isostructural and their structures were characterised both by X-ray diffraction on powder and single crystals. They crystallise in the monoclinic crystal system, space-group type P21 (no. 4) with a pseudo-hexagonal lattice, as shown by the lattice parameters of Mn(IO3)2 for example: a = 11.247(1) Å, b = 5.045(1) Å, c = 11.246(1) Å, β = 120.02(1)°, V = 552.5(1) Å3, Z = 4. This monoclinic symmetry with a ∼ c and β ∼ 120° leads to a three-individual pseudo-hexagonal twin by pseudo-merohedry. The structure reveals a three-dimensional network in which each octahedrally coordinated cation is linked to ten others via iodate bridges. All these metal iodates generate second harmonics.

Hydrothermal Synthesis and Crystal Structures of Two NLO Compounds, NaIO3×H2O and In(IO3)3.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

New Metal Iodates: Syntheses, Structures, and Characterizations of Noncentrosymmetric La(IO3)3 and NaYI4O12 and Centrosymmetric β‐Cs2I4O11 and Rb2I6O15 (OH)2×H2O.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

New Metal Iodates: Syntheses, Structures, and Characterizations of Noncentrosymmetric La(IO3)3 and NaYI4O12 and Centrosymmetric β-Cs2I4O11 and Rb2I6O15(OH)2·H2O

Four new metal iodates, beta-Cs2I4O11, Rb2I6O15(OH)2.H2O, La(IO3)3, and NaYI4O12, have been synthesized hydrothermally, and the structures were determined by single-crystal X-ray diffraction techniques. All of the reported materials contain I5+ cations that are in asymmetric coordination environments attributable to their stereoactive lone pair. Second-order nonlinear optical measurements on noncentrosymmetric La(IO3)3 and NaYI4O12, using 1064-nm radiation, indicate that both materials have second-harmonic-generating properties with efficiencies of approximately 400xSiO2. Converse piezoelectric measurements revealed d33 values of 5 and 138 pm V-1 for La(IO3)3 and NaYI4O12, respectively. Infrared and Raman spectroscopy and thermogravimetric analyses are also presented for all of the reported materials. Crystal data: beta-Cs2I4O11, monoclinic, space group P2(1)/n (No. 14), with a=12.7662(14) A, b=7.4598(8) A, c=14.4044(16) A, beta=106.993(2) degrees, V=1311.9(2) A3, and Z=4; Rb2I6O15(OH)2.H2O, triclinic, space group P (No. 2), with a=7.0652(17) A, b=7.5066(18) A, c=18.262(4) A, alpha=79.679(4) degrees, beta=85.185(4) degrees, gamma=70.684(4) degrees, V=898.9(4) A3, and Z=2; La(IO3)3, monoclinic, space group Cc (No. 9), with a=12.526(2) A, b=7.0939(9) A, c=27.823(4) A, beta=101.975(4) degrees, V=2418.4(6) A3, and Z=4; NaYI4O12, monoclinic, space group Cc (No. 9), with a=31.235(3) A, b=5.5679(5) A, c=12.5451(12) A, beta=91.120(3) degrees, V=2181.3(4) A3, and Z=4.

Hydrothermal synthesis and crystal structures of two NLO compounds, NaIO 3·H 2O and In(IO 3) 3

Two metal iodates, NaIO 3·H 2O and In(IO 3) 3, have been prepared by hydrothermal reactions at 170 °C. The X-ray structural analysis showed that NaIO 3·H 2O crystallizes in a monoclinic space group C2 with a = 14.175(3) Å, b = 3.6688(3) Å, c = 9.666(1) Å, β = 124.41(1)°, Z = 4 and In(IO 3) 3 in a hexagonal group P6 3 with a = 9.5463(8) Å, c = 5.2745(8) Å, Z = 2. NaIO 3·H 2O represents a new structure type and it can be viewed as a layered compound consisting of two-dimensional layers of edge-sharing NaO 7 monocapped octahedra that are capped by IO 3 − groups, while In(IO 3) 3 is a new compound containing slightly distorted InO 6 octahedra that are bridged by IO 3 − groups giving rise to a three-dimensional polar network. Both compounds crystallize in non-centrosymmetric, chiral space groups.

New d0 Transition Metal Iodates: Synthesis, Structure, and Characterization of BaTi(IO3)6, LaTiO(IO3)5, Ba2VO2(IO3)4× (IO3), K2MoO2(IO3)4, and BaMoO2(IO3)4×H2O.

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New d0 Transition Metal Iodates: Synthesis, Structure, and Characterization of BaTi(IO3)6, LaTiO(IO3)5, Ba2VO2(IO3)4·(IO3), K2MoO2(IO3)4, and BaMoO2(IO3)4·H2O

Five new d0 transition metal iodates, BaTi(IO3)6, LaTiO(IO3)5, Ba2VO2(IO3)4.(IO3), K2MoO2(IO3)4, and BaMoO2(IO3)4.H2O, have been synthesized by hydrothermal methods using Ba(OH)2.8H2O, La2O3, K2CO3, TiO2, V2O5, MoO3, and HIO3 as reagents. The structures of these compounds were determined by single-crystal X-ray diffraction. All of the reported materials have zero-dimensional or pseudo-one-dimensional crystal structures composed of MO6 (M = Ti4+, V5+, or Mo6+) octahedra connected to IO3 polyhedra. Infrared and Raman spectroscopy, thermogravimetric analysis, and UV-vis diffuse reflectance spectroscopy are also presented. Crystal data: BaTi(IO3)6, trigonal, space group R-3 (No. 148), with a = b = 11.4711(10) A, c = 11.1465(17) A, V = 1270.2(2) A3, and Z = 3; LaTiO(IO3)5, monoclinic, space group P2(1)/n (No. 14), with a = 7.4798(10) A, b = 18.065(2) A, c = 10.4843(14) A, beta = 91.742(2) degrees , V = 1416.0(3) A3, and Z = 4; Ba2VO2(IO3)4.(IO3), monoclinic, space group P2(1)/c (No. 14), with a = 7.5012(9) A, b = 33.032(4) A, c = 7.2150(9) A, beta = 116.612(2) degrees , V = 1598.3(3) A3, and Z = 4; K2MoO2(IO3)4, monoclinic, space group C2/c (No. 15), with a = 12.959(2) A, b = 6.0793(9) A, c = 17.748(3) A, beta = 102.410(4) degrees , V = 1365.5(4) A3, and Z = 4; BaMoO2(IO3)4.H(2)O, monoclinic, space group P2(1)/n (No. 14), with a = 13.3368(17) A, b = 5.6846(7) A, c = 18.405(2) A, beta = 103.636(2) degrees , V = 1356.0(3) A3, and Z = 4.

Hydrothermal synthesis and crystal structures of Nd(IO 3) 3 and Al(IO 3) 3

Two metal iodates, Nd(IO 3) 3 and Al(IO 3) 3, have been prepared by hydrothermal reactions at 170 °C. The X-ray single-crystal structural analysis showed that Nd(IO 3) 3 presented here is a new polymorph crystallizing in a monoclinic space group P2 1/ n with a = 8.859(1) Å, b = 5.9296(5) Å, c = 15.301(3) Å, β = 96.95(1)°, Z = 4. Al(IO 3) 3 crystallizes in a non-centrosymmetric group P6 3 with a = 9.003(1) Å, c = 5.2406(5) Å, Z = 2. The crystal structure of Nd(IO 3) 3 consists of 1D chains of edge-sharing NdO 9 polyhedra, which are stitched into slabs through the bridging IO 3 − groups; and slabs are held together via the weak I O bonds resulting in a 3D framework. Al(IO 3) 3 is characterized by the slightly distorted AlO 6 octahedra that are bridged by IO 3 − groups giving rise to a 3D polar network. Infrared spectra further confirmed that both compounds contain low symmetric IO 3 − groups.

Morphology and optical spectra of metal iodate microcrystals in porous matrices

Microcrystals of iodates of mercury, lead, thallium, and bismuth were grown in pores of glass and polymer matrices from solutions or through sublimation in vacuum. Images of these microcrystals embedded in matrices were obtained with an electron microscope. Exciton absorption and luminescence spectra of the microcrystals revealed a strong difference in the temperature regions of stability of the various structural modfications between bulk crystals and microcrystals of some iodates. The absorption and luminescence spectra are broadened inhomogeneously because of considerable size dispersion of the microcrystals and exhibit quantum confinement effects. The exciton emission spectra show that exciton interaction in microcrystals becomes significant at very low optical pumping levels because of efficient excitation transfer from the matrix.