Bi(IO3)F2: The First Metal Iodate Fluoride with a Very Strong Second Harmonic Generation Effect

The first metal iodate fluoride, Bi(IO₃)F₂, with a strong second harmonic generation (SHG) effect has been prepared. Bi(IO₃)F₂ crystallizes in the polar space group C2 and features a three‐dimensional [BiF₂]⁺ cationic framework with IO₃ groups capping the inner walls of the one‐dimensional tunnels. This [BiF₂]⁺ cationic framework acts as a template for the assembly of the polar IO₃ units in a favorable superposed fashion, which leads to the polar structure of the material. Bi(IO₃)F₂ displays a rather wide transmittance window (0.3–11 μm) and exhibits a very strong SHG response that is about 11.5 times larger than that of KH₂PO₄ (KDP) under 1064 nm laser radiation and the same as that of KTiOPO₄ (KTP) under 2.05 μm laser radiation. Preliminary investigations indicate that Bi(IO₃)F₂ is a promising nonlinear optical material in the visible and mid‐IR region.     

JO2F3, seine Struktur und F-Ionen-Akzeptor-Eigenschaften

IO₂F₃, originally assumed to have a trigonal bipyramidal structure, is polymeric. Mass spectra confirm the existence of molecules with molecular weights up to three times the formula weight. Chemically, IO₂F₃ is a strong Lewis acid and fluorine ion acceptor, thus forming the anion IO₂F₄ ^?. With SbF₅ it forms a further polymeric compound (IO₂F₃·SbF₅) _n .¹⁹F-NMR, mass, IR and Raman spectra confirm the proposed structures.     

K3V2O3F4(IO3)3: a high-performance SHG crystal containing both five and six-coordinated V5+ cations

The combination of d⁰ transition metal oxofluorides with iodate anions helps to synthesize polar crystals. Herein, a novel polar crystal, K₃V₂O₃F₄(IO₃)₃, which is the first metal vanadium iodate with two types of V⁵⁺-centered polyhedra (VO₄F₂ octahedron and VO₃F₂ trigonal bipyramid), has been prepared hydrothermally. It crystallizes in the polar space group of Cmc2₁ and its structure displays an unprecedented 0D [V₂O₃F₄(IO₃)₃]³⁻ anion, which is composed of Λ-shaped cis-[VO₂F₂(IO₃)₂]³⁻ and [VO₂F₂(IO₃)]²⁻ anions interconnected via the corner-sharing of one oxo anion. The synergy gained from the VO₄F₂, VO₃F₂ and IO₃ groups resulted in K₃V₂O₃F₄(IO₃)₃ exhibiting both a strong second-harmonic generation (SHG) response (1.3 × KTiOPO₄) under 2050 nm laser irradiation and a large birefringence (0.158 @ 2050 nm). This study provides a facile route for designing SHG materials by assembling various vanadium oxide-fluoride motifs and iodate anions into one compound.

K₃V₂O₃F₄(IO₃)₃, which is the first metal vanadium iodate containing two different V-centered polyhedra, exhibits a strong SHG effect of 1.3 × KTP and a large birefringence of 0.158 @ 2050 nm.     

ABi2(IO3)2F5 (A=K,Rb, and Cs): A Combination of Halide and Oxide Anionic Units To Create a Large Second‐Harmonic Generation Response with a Wide Bandgap

A family of nonlinear optical materials that contain the halide, oxide, and oxyhalide polar units simultaneously in a single structure, namely ABi₂(IO₃)₂F₅ (A=K ( 1 ), Rb ( 2 ), and Cs ( 3 )), have been designed and synthesized. They crystallize in the same polar space group (P 2₁) with a two‐dimensional double‐layered framework constructed by [BiF₅]²⁻ and [BiO₂F₄]⁵⁻ units connected to each other by four F atoms, in which two [IO₃]⁻ groups are linked to [BiO₂F₄]⁵⁻ unit on the same side. A hanging Bi−F bond of [BiF₅]²⁻ unit is located on the other side via ionic interaction with the layer‐inserted alkali metal ions to form three‐dimensional structure. The well‐ordered alignments of these polar units lead to a very strong second‐harmonic generation response of 12 ( 1 ), 9.5 ( 2 ), and 7.5 ( 3 ) times larger than that of potassium dihydrogen phosphate under 1064 nm laser radiation. All of them exhibited a wide energy bandgap over 3.75 eV, suggesting that they will have a high laser damage threshold.     

ABi2(IO3)2F5 (A=K,Rb, and Cs): A Combination of Halide and Oxide Anionic Units To Create a Large Second‐Harmonic Generation Response with a Wide Bandgap

A family of nonlinear optical materials that contain the halide, oxide, and oxyhalide polar units simultaneously in a single structure, namely ABi₂(IO₃)₂F₅ (A=K ( 1 ), Rb ( 2 ), and Cs ( 3 )), have been designed and synthesized. They crystallize in the same polar space group (P 2₁) with a two‐dimensional double‐layered framework constructed by [BiF₅]²⁻ and [BiO₂F₄]⁵⁻ units connected to each other by four F atoms, in which two [IO₃]⁻ groups are linked to [BiO₂F₄]⁵⁻ unit on the same side. A hanging Bi−F bond of [BiF₅]²⁻ unit is located on the other side via ionic interaction with the layer‐inserted alkali metal ions to form three‐dimensional structure. The well‐ordered alignments of these polar units lead to a very strong second‐harmonic generation response of 12 ( 1 ), 9.5 ( 2 ), and 7.5 ( 3 ) times larger than that of potassium dihydrogen phosphate under 1064 nm laser radiation. All of them exhibited a wide energy bandgap over 3.75 eV, suggesting that they will have a high laser damage threshold.     

Synthesis, vibrational and NMR spectroscopic characterization of [N(CH3)4][IO2F2] and X-ray crystal structure of [N(CH3)4]2[IO2F2][HF2]

The salt, [N(CH₃)₄][IO₂F₂], was prepared from [N(CH₃)₄][IO₃] and 49% aqueous HF, and characterized by Raman, infrared, and ¹⁹F NMR spectroscopy. Crystals of [N(CH₃)₄]₂[IO₂F₂][HF₂] were obtained by reduction of [N(CH₃)₄][cis-IO₂F₄] in the presence of [N(CH₃)₄][F] in CH₃CN solvent and were characterized by Raman spectroscopy and single-crystal X-ray diffraction: C2/m, a = 14.6765(2) Å, b = 8.60490(10) Å, c = 13.9572(2) Å, β = 120.2040(10)°, V = 1523.35(3) Å³, Z = 4 and R = 0.0192 at 210 K. The crystal structure consists of two IO₂⁻F₂ anions that are symmetrically bridged by two H⁻F₂ anions, forming a [F₂O₂I(FHF)₂IO₂F₂]⁴⁻ dimer. The symmetric bridging coordination for the H⁻F₂ anion in this structure represents a new bonding modality for the bifluoride anion.     

Preparation de nouveaux difluorodioxophosphates a partir de l'oxyde de difluorure de phosphoryle. Partie II. Reactions sur les acides iodique et periodique.

The new compounds IO₂PO₂F₂ and IO₃PO₂F₂ have been prepared by the reaction of iodic and periodic acids on F₂OPOPOF₂. Raman spectra show a dimeric structure for IO₃⁺ ion but a monomeric structure for IO₂⁺ ion.     

(NH4)Bi2(IO3)2F5: An Unusual Ammonium‐Containing Metal Iodate Fluoride Showing Strong Second Harmonic Generation Response and Thermochromic Behavior

An ammonium‐containing metal iodate fluoride compound, (NH₄)Bi₂(IO₃)₂F₅, featuring a two‐dimensional double‐layered framework constructed by [BiO₂F₅]^6? and [BiO₄F₄]^9? polyhedra, as well as [IO₃]^? groups, was successfully synthesized. The well‐ordered alignment of these SHG‐active units leads to an extraordinary strong SHG response of 9.2 times that of KDP. Moreover, this compound possesses a large birefringence (Δn=0.0690 at 589.3 nm), a wide energy band gap (E_g=3.88 eV), and a high laser damage threshold (LDT; 40.2×AgGaS₂). In particular, thermochromic behavior was observed for the first time in this type of compound. Such multifunctional crystals will expand the application of nonlinear optical materials.     

K2Au(IO3)5 and β‐KAu(IO3)4: Polar Materials with Strong SHG Responses Originating from Synergistic Effect of AuO4 and IO3 Units

Two new polar potassium gold iodates, namely, K₂Au(IO₃)₅ (Cmc2₁) and β‐KAu(IO₃)₄ (C2), have been synthesized and structurally characterized. Both compounds feature zero‐dimensional polar [Au(IO₃)₄]^? units composed of an AuO₄ square‐planar unit coordinated by four IO₃^? ions in a monodentate fashion. In β‐KAu(IO₃)₄, isolated [Au(IO₃)₄]^? ions are separated by K⁺ ions, whereas in K₂Au(IO₃)₅, isolated [Au(IO₃)₄]^? ions and non‐coordinated IO₃^? units are separated by K⁺ ions. Both compounds are thermally stable up to 400 °C and exhibit high transmittance in the NIR region (λ=800–2500 nm) with measured optical band gaps of 2.65 eV for K₂Au(IO₃)₅ and 2.75 eV for β‐KAu(IO₃)₄. Powder second‐harmonic generation measurements by using λ=2.05 μm laser radiation indicate that K₂Au(IO₃)₅ and β‐KAu(IO₃)₄ are both phase‐matchable materials with strong SHG responses of approximately 1.0 and 1.3 times that of KTiOPO₄, respectively. Theoretical calculations based on DFT methods confirm that such strong SHG responses originate from a synergistic effect of the AuO₄ and IO₃ units.     

(NH4)Bi2(IO3)2F5: An Unusual Ammonium-Containing Metal Iodate Fluoride Showing Strong Second Harmonic Generation Response and Thermochromic Behavior

An ammonium-containing metal iodate fluoride compound, (NH₄)Bi₂(IO₃)₂F₅, featuring a two-dimensional double-layered framework constructed by [BiO₂F₅]⁶⁻ and [BiO₄F₄]⁹⁻ polyhedra, as well as [IO₃]⁻ groups, was successfully synthesized. The well-ordered alignment of these SHG-active units leads to an extraordinary strong SHG response of 9.2 times that of KDP. Moreover, this compound possesses a large birefringence (Δn=0.0690 at 589.3 nm), a wide energy band gap (E_g=3.88 eV), and a high laser damage threshold (LDT; 40.2×AgGaS₂). In particular, thermochromic behavior was observed for the first time in this type of compound. Such multifunctional crystals will expand the application of nonlinear optical materials.     

CsVO2F(IO3): An Excellent SHG Material Featuring an Unprecedented 3D [VO2F(IO3)]− Anionic Framework

The first alkali-metal vanadium iodate fluoride, CsVO₂F(IO₃), with a novel 3D anionic framework, has been rationally designed and hydrothermally synthesized. The 3D [VO₂F(IO₃)]⁻ framework in CsVO₂F(IO₃) is built from 0D Λ-shaped cis-[VO₃F(IO₃)₂]⁴⁻ polyanions via corner-sharing of oxo anions and bridging of the iodate groups. CsVO₂F(IO₃) displays both a strong second-harmonic generation (SHG) 1.1 times as strong as KTiOPO₄ (KTP) under 2.05 μm laser radiation and high laser-induced damage threshold (LIDT) of 107.9 MW cm⁻². This work provides a new route to design SHG crystals with stable 3D anionic structures from low-dimensional structural building units.     

CsVO2F(IO3): An Excellent SHG Material Featuring an Unprecedented 3D [VO2F(IO3)]− Anionic Framework

The first alkali‐metal vanadium iodate fluoride, CsVO₂F(IO₃), with a novel 3D anionic framework, has been rationally designed and hydrothermally synthesized. The 3D [VO₂F(IO₃)]^? framework in CsVO₂F(IO₃) is built from 0D Λ‐shaped cis‐[VO₃F(IO₃)₂]^4? polyanions via corner‐sharing of oxo anions and bridging of the iodate groups. CsVO₂F(IO₃) displays both a strong second‐harmonic generation (SHG) 1.1 times as strong as KTiOPO₄ (KTP) under 2.05 μm laser radiation and high laser‐induced damage threshold (LIDT) of 107.9 MW cm^?2. This work provides a new route to design SHG crystals with stable 3D anionic structures from low‐dimensional structural building units.     

Explorations of New SHG Materials in Mercury Iodate Sulfate System**

Through systematic experiments, two novel mercury iodate sulfates, namely, Hg₂(IO₃)₂(SO₄)(H₂O) and Hg₂(IO₃)₂(SO₄) were obtained. They crystallize in monoclinic space group C2 and C2/c, respectively. Hg₂(IO₃)₂(SO₄)(H₂O) exhibits the [Hg(IO₃)]⁺ polar cationic layer inherited from Hg(IO₃)₂ and the three-dimensional (3D) framework inherited from HgSO₄. This enables Hg₂(IO₃)₂(SO₄)(H₂O) to generate a strong second harmonic generation (SHG) response of 6 times that of KH₂PO₄ (KDP). The structure of Hg₂(IO₃)₂(SO₄) is very similar to that of Hg₂(IO₃)₂(SO₄)(H₂O), and they can be transformed into each other. Hg₂(IO₃)₂(SO₄)(H₂O) shows a large optical band gap of 3.98 eV and a high dehydration temperature of 250 °C. This study indicates that by reasonable design, the introduction of multiple functional groups into a compound may combine their advantages to achieve good overall optical performance.     

[GaF(H2O)][IO3F]: a promising NLO material obtained by anisotropic polycation substitution

A novel salt-inclusion fluoroiodate [GaF(H₂O)][IO₃F] derived from CsIO₂F₂ was ingeniously obtained through anisotropic polycation substitution. Because the catenulate [GaF(H₂O)]²⁺ framework serves as a template for the favorable assembly of the polar [IO₃F]²⁻ groups and contributes to the nonlinear coefficient, [GaF(H₂O)][IO₃F] exhibits a greatly improved second-harmonic generation (SHG) effect of 10 times that of KH₂PO₄ (KDP) and a considerable band gap of 4.34 eV compared to the parent compound CsIO₂F₂ (3 × KDP, 4.5 eV). Particularly, to the best of our knowledge, [GaF(H₂O)][IO₃F] has the largest laser-induced damage threshold (LDT) of 140 × AgGgS₂ of the reported iodates. All these results signify that [GaF(H₂O)][IO₃F] is a promising nonlinear optical (NLO) crystal. This work also proposes that anisotropic polycation substitution is an effective approach to optimize the SHG effect and develop excellent NLO materials.

A novel salt-inclusion fluoroiodate nonlinear optical material, [GaF(H₂O)][IO₃F], is derived from CsIO₂F₂ through polycation substitution, and it exhibits an intense SHG effect of 10 times that of KH₂PO₄ and improved overall performance.     

Ce(IO3)2F2⋅H2O: The First Rare-Earth-Metal Iodate Fluoride with Large Second Harmonic Generation Response

The first rare earth metal iodate fluoride, Ce(IO₃)₂F₂⋅H₂O, was synthesized by a hydrothermal method. In the structure, CeO₅F₄ polyhedra connect with isolated IO₃ groups to form 1D infinite [Ce(IO₃)₂F₂] chains, which interconnect with each other by weak hydrogen bonds to construct the whole structure. Ce(IO₃)₂F₂⋅H₂O produces a large second harmonic generation response, which is three times that of potassium dihydrogenphosphate. Theoretical calculations with DFT and dipole moments were performed to illustrate the relationships between the structure and the properties. The results show that Ce(IO₃)₂F₂⋅H₂O is a new iodate fluoride with novel structure and potential applications in nonlinear optics.     

Chromatographic Behaviour of Anions of Zr (IV) Molybdate Papers and Silica Gel ‘G’ Thin Layers

Abstract

Ion exchange potential of Zr (IV) molybdate and silica gel ‘G’ has been explored in paper chromatography and thin layer chromatographic studies for the separation of anions from one another. Several Important and difficult separations of anions have been achieved as a result of these studies. IO^? ₃ - BrO₃ ^?, Br^? - NO₂ ^?, IO₄ ^? - I^?, NO₂ ^? - NO₃ ^?, NO₃ ^? - BO₃ ^?, NO₃ ^? - BrO₃ ^?, PO₄ ^— - F^? and PO₄ ^— - IO₃ ^? are separations of practical Interest.     

In[IO3](OH)2 – New member of hydrous and anhydrous iodate family with indium

A new indium iodate hydrate In[IO₃](OH)₂ was synthesized by the hydrothermal methods. Single crystal X-ray diffraction revealed centrosymmetric Pnma space group. [IO₃]-groups have typical umbrella-like configuration: iodine atom and three oxygens with I–O distances ∼1.8 Å. In-octahedra have 4 equatorial OH-groups and 2 apical O-atoms of 2 [IO₃]-groups and are connected into the layers via OH-groups. It is found that indium iodate family without any other metals is a regular row of compounds: anhydrous In[IO₃]₃, one hydrated In[IO₃]₂(OH)·H₂O, new two hydrated In[IO₃](OH)₂ and “end member” represented by three hydrated hydroxide In(OH)₃. Chemical relations are parallel to the structural: In-octahedral framework in In-hydroxide, In-octahedral layer as a fragment of the framework, In-octahedral chain as a fragment of the layer, isolated In-octahedra as a fragment of the chain with no In-octahedral condensation via vertices but only via [IO₃]-groups in anhydrous In-iodate. If alkali metals are introduced in anhydrous In-iodates, their influence is different. Large metals as K, Rb, Cs hinder condensation of {In[IO₃]₆}³⁻ blocks which are isolated in the structures whereas smaller Li, Na metals allows condensation up to bands {In[IO₃]₄}¹⁻_∞. Octahedral chains selected in hydrated In-iodates are similar to chains in nonlinear optical compound TiO[IO₃]₂. The reasons of polarity or non-polarity and possible elements substitutions promising for properties are discussed.     

Gitterschwingungsspektren. LXIII. Be(lO3)2 · 4 H2O,ein Hydrat mit ungewöhnlicher Bindungsstruktur und Gitterdynamik

Lattice Vibration Spectra. LXIII. Be(IO₃)₂ · 4 H₂O, a Hydrate with Unusual Bonding and Lattice Dynamics The IR and Raman spectra (4000–50 cm^?1) of Be(IO₃)₂ · 4 H₂O and of deuterated specimens are recorded at 90 and 300 K and discussed in terms of the unusual relations of the masses of the atoms involved and the large polarization power of the beryllium ions. Thus, the translatory modes of the Be²⁺ ions (BeO₄ skeleton vibrations), the librations of the H₂O molecules, and the internal vibrations of the IO₃^? ions in the spectral regions of 300–400 and 600–1000 cm^?1 couple and coincide producing unusual v_H/v_D isotopic ratios of partly < 1. The H-bond donor strengths of the water molecules is so much increased (due to the very large ionic potential of Be²⁺ ions, viz. 49 e nm^?1) (synergetic effect) that the H-bonds formed are similar in strength as those in hydrates of hydroxides with the very strong H-bond acceptor group OH^? (v_OD of matrix isolated HDO molecules 2 074 and 2 244 (H₂O I) and 2 206 and 2 349 cm^?1 (H₂O II))     

Study of some phenolic-iodine redox polymeric products by thermal analyses and mass spectrometry

Summary This paper describes the use of the mass spectrometry (MS), thermal analyses (TA) and other physico-chemical methods to investigate the structure of two newly synthesized phenolic-iodine derivative polymeric products. These two products are formed as a result of redox-interaction of adrenaline hydrogen tartrate (AHT, I) with iodate (IO^-₃) and periodate (IO^-₄). The characterization of the two products were achieved satisfactorily by using the above tools and their proposed general formulae, were found to be C₅₂H₆₇O₃₆N₄I (AHT- IO^-₃, II) and C₂₆H₃₄O₁₈N₂I₂(AHT- IO^-₄, III). The fragmentation behavior of the main compound (AHT) in MS and TA (TG and DTA) techniques was investigated and compared. The results obtained were used to explain the fragmentation of the products AHT- IO^-₃and AHT- IO^-₄in mass spectrometry and thermal analyses techniques. The stabilities of different fragments were discussed. The results indicate that the two techniques are supporting each other in which the mass spectrometry provides the structural information in gas phase while the thermal analyses provides the quantitative fragmentation in the solid-state.     

A Facile Route to Nonlinear Optical Materials: Three‐Site Aliovalent Substitution Involving One Cation and Two Anions

Two mixed‐metal gallium iodate fluorides, namely, α‐ and β‐Ba₂[GaF₄(IO₃)₂](IO₃) ( 1 and 2 ), have been designed by the aliovalent substitutions of α‐ and β‐Ba₂[VO₂F₂(IO₃)₂](IO₃) ( 3 and 4 ) involving one cationic and two anionic sites. Both 1 and 2 display large second‐harmonic generation responses (≈6×KH₂PO₄ (KDP)), large energy band gaps (4.61 and 4.35 eV), wide transmittance ranges (≈0.27–12.5 μm), and high relevant laser‐induced damage thresholds (29.7× and 28.3×AgGaS₂, respectively), which indicates that 1 and 2 are potential second‐order nonlinear optical materials in the ultraviolet to mid‐infrared. Our studies propose that three‐site aliovalent substitution is a facile route for the discovery of good NLO materials.