IO3 Groups Research Articles

From NaGa(IO3)3F to NaGa(IO3)2F2 and NaGa(IO3)4: The Effects of Chemical Substitution between F- Anions and IO3- Groups on the Structures and Properties of Gallium Iodates.

Introducing F- anions or substituting F- anions with IO3- groups has been proven to be ideal strategies for designing novel noncentrosymmetric (NCS) and polar materials, yet systematic investigation into the effect of F- anions or the substitution of IO3- for F- anions on structures and properties remains rarely explored. Herein, two new gallium iodates, NaGa(IO3)2F2 (1) and NaGa(IO3)4 (2), were successfully designed and synthesized based on NaGa(IO3)3F by introducing more F- anions and replacing F- anions with IO3 groups, respectively. Structurally, in compound 1, the adjacent [GaF3(IO3)3]3- polyanions are connected in an antiparallel manner, resulting in a complete cancellation of local polarity. While in compound 2, all IO3 groups in 2D [Ga(IO3)4]∞- layers are aligned, leading to large macroscopic polarization. Additionally, chemical substitution also results in a qualitative improvement in the functional properties of compound 2. It possesses strong SHG response (12 × KDP @1064 nm) and broad optical transparency, coupled with large birefringence (0.21 @1064 nm), showcasing its promise as a promising nonlinear optical (NLO) crystal. The effects of chemical substitution between F- anions and IO3- groups on the structures and properties are discussed in detail.

α- and β-(C4H5N2O)(IO3)·HIO3: Two SHG Materials Based on Organic-Inorganic Hybrid Iodates.

Organic-inorganic hybrid nonlinear optical (NLO) materials are highly anticipated because of the integration of both merits of the organic and inorganic moieties. Herein, the 2-pyrimidinone cation (C4H5N2O)+ has been incorporated into the iodate system to form two polymorphic organic-inorganic hybrid iodates, namely, α- and β-(C4H5N2O)(IO3)·HIO3. They crystallize in different polar space groups (Ia and Pca21), and their structures feature one-dimensional (1D) chain structures composed of (C4H5N2O)+ cations, IO3- anions, and HIO3 molecules interconnected via hydrogen bonds. α- and β-(C4H5N2O) (IO3)·HIO3 exhibit strong and moderate second-harmonic-generation (SHG) responses of 6.4 and 0.9 × KH2PO4 (KDP), respectively, the same band gaps of 3.65 eV, and high powder laser-induced damage threshold (LIDT) values [51 and 57 × AgGaS2 (AGS)]. The results of theoretical calculations revealed that the large SHG effect of α-(C4H5N2O)(IO3)·HIO3 originated from the IO3 and HIO3 groups. This work indicates that (C4H5N2O)+ is a potential group for designing new NLO materials with brilliant optical performances.

M(OH)2]3(IO3)(SeO4)·H2O (M = Ga and In): metal iodate–selenate nonlinear optical materials with a hexagonal tungsten oxide-type topology

The designed [M(OH)2]3(IO3)(SeO4)·H2O (M = Ga and In) feature∞[MO2(OH)2]3−layers composed of M3O6(OH)9trimeric units capped by SeO4and IO3groups from different sides of the layers. They exhibit moderate SHG effects and large LIDT values.

MIO3F (M = Co and Ni): Magnetic Iodate Fluorides with Zigzag Chains.

The iodate anion group has been widely used for design and synthesis of functional materials including nonlinear optical materials but rarely for magnetic materials. Particularly, none of magnetic iodate fluorides has been reported yet. In this work, first, two novel magnetic iodate fluorides MIO3F (M = Co 1 and Ni 2) have been synthesized by a hydrothermal method and characterized by magnetic susceptibility, magnetization, and heat capacity measurements as well as thermogravimetry, Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy. Compounds 1 and 2 are isostructural and crystallize in the monoclinic space group P21/n with alternating M2+-F2-M2+-O2-M2+ zigzag spin chains along the b axis, which are further separated by triangular IO3 groups in the ab plane. Magnetic susceptibilities suggest that 1 exhibits an antiferromagnetic long-range order (LRO) at 16.5 K, confirmed by heat capacity results with released entropy consistent with the theoretical value for a pseudo-spin of 1/2 for Co2+ at low temperatures. Meanwhile, 2 displays a broad maximum around 10.5 K for low dimensional magnetism followed by a sharp peak at 5.7 K indicating the occurrence of an LRO transition, in good agreement with the heat capacity measurement. Field-dependent magnetizations show an obvious spin-flop transition around 4.5 T and a magnetic hysteresis loop between 4.5 and 7 T for 1, but only a slight slope change could be observed around 2.3 T for 2. Thermal stability, FT-IR, and UV-vis-NIR spectroscopy of 1 and 2 are also reported.

Polar lanthanide copper iodates LnCu(IO3)5 (Ln = La, Ce, Pr, and Nd): Synthesis, crystal structure and characterization

Four new polar lanthanide copper iodates LnCu(IO3)5 (Ln ​= ​La, Ce, Pr, and Nd) were synthesized by the hydrothermal method at 220 ​°C. The four compounds are isostructural and they can be viewed as derivation from two parts: the [Ln(IO3)3] layers from the Ln(IO3)3 with 3D framework and the [Cu(IO3)2] chain from the α-Cu(IO3)2 with 2D layer structure. As the compounds crystallize in the noncentrosymmetric orthorhombic space group Pna21, they may find interesting applications as nonlinear optical crystals. The second-harmonic generation (SHG) response of powder LaCu(IO3)5 is measured to be around 0.5 times that of KDP. The measurement of SHG response versus particle sizes of samples indicates that LaCu(IO3)5 can achieve phase matching. In order to interpret the origination of SHG effects, the dipole moment of LaO9, CuO6 and IO3 groups were calculated. It is suggested that the IO3 groups contribute mostly (∼90.7%) and the CuO6 groups contribute little (∼1.6%) to the SHG response of LaCu(IO3)5. The results of this research show that the combination of lanthanide and copper elements with the electron lone-pair I5+ cations can be a feasible way to fabricate new polar materials in the rare-earth and transition metal iodate system.

ZnIO3F: Zinc Iodate Fluoride with Large Birefringence and Wide Band Gap.

The first zinc iodate fluoride, ZnIO3F, was synthesized by the Zn2+ cation, the IO3 group, and fluorine ion, where Zn2+ is coordinated by O atoms from iodate and F atoms to form the ZnO4F2 polyhedron. It has outstanding optical characteristics, including large birefringence (Δ = 0.219 at 546 nm), wide band gap (Eg = 4.2 eV), and good thermal stability (over 475 °C), showing a subtle balance between the wide band gap and birefringence.

Helix-constructed polar rare-earth iodate fluoride as a laser nonlinear optical multifunctional material.

The first trivalent rare-earth iodate fluoride nonlinear optical (NLO) crystal, Y(IO3)2F (YIF), was successfully designed and synthesized, featuring polarization-favorable helical chains constructed from trans-YO6F2 polyhedra and IO3 groups. It exhibited a suitable balance of a wide transparency range of 0.26-10.0 μm, high laser damage threshold (LDT) of 39.6 × AgGaS2, and moderate second harmonic generation (SHG) effect of 2 × KDP. A series of doped RE:YIF (RE = Pr, Nd, Dy, Ho, Er, Tm, and Yb) crystals were easily synthesized benefiting from the spring-shaped helix structure, which possess wide absorption and emission peaks as well as long lifetime, especially in the visible and near-infrared regions. Particularly, the remarkable fluorescence properties of Nd and Yb doped YIF crystals are comparable to and even better than those of traditional self-frequency doubling (SFD) crystals such as YAB, YCOB, and GdCOB. Thus, these RE-doped YIF crystals are promising laser SFD crystals. This work also indicated that constructing helical chains should be an effective strategy for the design of inorganic polar materials.

Synthesis, structure, and third-harmonic generation measurements of a mixed alkali metal iodate, KLi2(IO3)3

Pure polycrystalline samples and single crystals of a mixed alkali metal iodate, KLi2(IO3)3 were synthesized through standard solid state and hydrothermal reactions, respectively, by using Li2CO3, K2CO3, and I2O5 as reagents. Single-crystal X-ray diffraction analysis suggests that KLi2(IO3)3 exhibits a corrugated layered structure consisting of IO3 distorted trigonal pyramids, LiO4 tetrahedra, and K+ cations. Within the layer, both five-membered rings (5-MRs) and six-membered rings (6-MRs) exist. UV–vis diffuse reflectance spectral data suggest that KLi2(IO3)3 has a wide optical band gap of ca. 4.25 ​eV. Infrared spectrum of the title compound clearly confirms the existence of IO3 groups in the backbone. The framework of the iodate is thermally stable to ca. 450 ​°C. Third-harmonic generation measurements using 1500 ​nm radiation indicate that the third-order nonlinear optical susceptibility of KLi2(IO3)3 is ca. 3 times that of α-SiO2. The laser-induced damage threshold of KLi2(IO3)3 is comparable to that of α-SiO2. Calculated local dipole moment values of IO3 polyhedra are also reported to better understand the asymmetric coordination environment.

Spontaneous Polarization Effect and Photocatalytic Activity of Layered Compound of BiOIO3.

Internal polarized electric field is found to be an effective and available strategy to separate photogenerated electron-hole pairs. By this method, the efficiency of photocatalytic reactions can be obviously enhanced. Here, the layered compound of BiOIO3 with spontaneous polarization was synthesized by a simple hydrothermal method. Taking another bismuth compound BiOI as a counterpart, which has a similar layered structure, the spontaneous polarization effects of BiOIO3 were analyzed and confirmed. The photocatalytic activity of BiOIO3 and BiOI were evaluated by the degradation of methyl orange. Methyl orange was almost completely photocatalytically decomposed by BiOIO3 and BiOI in 40 and 90 min, respectively. The separation and transfer behaviors of photogenerated electron-hole pairs were investigated by a series of photoelectrochemical characterizations. It is further proved the separation and transmission efficiency of BiOIO3 are higher than those of BiOI. According to the results of density of theory calculations, the internal polarized electric field in BiOIO3 is ascribed to the spatial asymmetry of the IO3 group, which is estimated to ∼1.5 × 1010 V/m. Under the action of this internal polarized electric field, the photogenerated electrons and holes would transfer along opposite directions, i.e., photogenerated electrons and holes respectively gather at the Bi/I side and O side. Additionally, superoxide radicals (•O2-) and holes (h+) are produced during the degradation process, which are responsible for the high visible-light photocatalytic activity. Finally, the cyclic degradation test proves that its photocatalytic performance has long-term stability. Therefore, BiOIO3 polar material can be used as one of the alternative materials for efficient photocatalytic reaction.

LiMII(IO3)3 (MII=Zn and Cd): Two Promising Nonlinear Optical Crystals Derived from a Tunable Structure Model of α‐LiIO3

AbstractExcellent nonlinear optical materials simultaneously meet the requirements of large SHG response, phase‐matching capability, wide transparency windows, considerable energy band‐gap, good thermal stability and structure stability. Herein, two new promising nonlinear optical (NLO) crystals LiMII(IO3)3 (MII=Zn and Cd) are rationally designed by the aliovalent substitution strategy from the commercialized α‐LiIO3 with the perfect parallel alignment of IO3 groups. Compared with parent α‐LiIO3 and related AI2MIV(IO3)6, the title compounds exhibit more stable covalent 3D structure, and overcome the racemic twinning problem of AI2MIV(IO3)6. More importantly, both compounds inherit NLO‐favorable structure merits of α‐LiIO3 and show larger SHG response (≈14× and ≈12×KDP), shorter absorption edge (294 and 297 nm) with wider energy band‐gap (4.21 and 4.18 eV), good thermal stability (460 and 430 °C), phase‐matching behaviors, wider optical transparency window and good structure stability, achieving an excellent balance of NLO properties.

LiMII (IO3 )3 (MII =Zn and Cd): Two Promising Nonlinear Optical Crystals Derived from a Tunable Structure Model of α-LiIO3.

Excellent nonlinear optical materials simultaneously meet the requirements of large SHG response, phase-matching capability, wide transparency windows, considerable energy band-gap, good thermal stability and structure stability. Herein, two new promising nonlinear optical (NLO) crystals LiMII (IO3 )3 (MII =Zn and Cd) are rationally designed by the aliovalent substitution strategy from the commercialized α-LiIO3 with the perfect parallel alignment of IO3 groups. Compared with parent α-LiIO3 and related AI 2 MIV (IO3 )6 , the title compounds exhibit more stable covalent 3D structure, and overcome the racemic twinning problem of AI 2 MIV (IO3 )6 . More importantly, both compounds inherit NLO-favorable structure merits of α-LiIO3 and show larger SHG response (≈14× and ≈12×KDP), shorter absorption edge (294 and 297 nm) with wider energy band-gap (4.21 and 4.18 eV), good thermal stability (460 and 430 °C), phase-matching behaviors, wider optical transparency window and good structure stability, achieving an excellent balance of NLO properties.

Five New Silver Rare‐Earth Iodates, AgLn(IO3)4 (Ln=Pr, Sm, Dy, Er and Tm): Synthesis, Structures and Properties

AbstractFive new silver rare‐earth iodates AgLn(IO3)4 (Ln= Pr, Sm, Dy, Er and Tm) have been synthesized first time by hydrothermal method, and their structures are confirmed by single crystal X‐ray diffraction. They are isomorphic of previous characterized AgM(IO3)4 (With M= Y, La, Nd, Eu, Gd, Bi) compounds and all crystallized in noncentrosymmetric (NCS) structure. Their structures contain LnO8 polyhedrons, which are interconnected through IO3 groups to form a complex two dimensional (2D) layer. Their powders all show nonlinear optical (NLO) effects which are 2.3 ‐ 4 times stronger than KH2PO4 (KDP) respectively. Energy dispersive X‐ray spectroscopy (EDS), Infrared region (IR) spectra, Ultra‐visible (UV/Vis) spectra and thermogravimetric analysis (TGA) are also performed.

Association of the ratio of CD8+ and CD163+ lymphocytes with clinical outcome in hepatocellular carcinoma.

e15613 Background: Within the tumor microenvironment (TME), infiltrating lymphocytes and myeloid cells including tumor-associated macrophages (TAMs) and tumor-associated neutrophils (TANs) are key players involved in liver cancer progression. The purpose of the study was to explorer whether distinct infiltrated immune cell features differentially affect clinical outcome in hepatocellular carcinoma (HCC). Methods: We obtained respectable stage II HCC specimens, along with adjacent para-tumor tissues from 221 patients who underwent surgical resection at Eastern Hepatobiliary Surgery Hospital, (in Shanghai, China) from 2015 through April 2018. CD8+, CD163+ and CD66B+ tumor-infiltrating lymphocytes (TILs) in the cancer area (CA) and stroma area (SA), as well paratumor stroma area, were analyzed by multiple immunohistochemistry. Results: Hierarchical clustering analysis of immune cell densities revealed that all HCC samples can be classified into three distinct groups. The three immune oncology types (IO-types) were characterized by a strong CD8 T cell density in CA and SA region (IO-1), an intermediate state of CD8 and CD163+ (IO-2), and a strong CD163+ macrophage density in IO-3. Remarkably increasing risks of mortality and recurrence, as well as elevated AST, ALP, GGT and AFP levels, were identified in IO-3 group, when compared with IO-1 group. We then identified that percentages of CA-CD8+ TILs in the tumor sample and SA-CD163+ macrophages in the para-tumor region showed opposite distribution pattern among the three IO types, suggesting a predictive role for CD8/TAM ratio in HCC cohort. Therefore, we next classified all HCC samples into two subgroups, according to the levels of tumor-CA-CD8/paratumor-SA-CD163 ratio. Expectedly, higher rate of CD8/CD163 represented significantly improved overall survival (OS) and progression free survival (PFS), verses lower rate of CD8/CD163. Further association studies suggested that the two subgroups correlated with HBV DNA, tumor size, and microvascular invasion (MVI). Of note, a prognostic signature combining portal vein tumor thrombus (PVTT) and CD8/CD163 ratio discriminated HCC patients into four subtypes with increasing risk of mortality and recurrence. Conclusions: The current results indicated that the CD8/CD163 is a novel, independent prognostic factor for a lower rate of disease recurrence and favorable OS in patients with resectable HCC.

HBa2.5(IO3)6(I2O5) and HBa(IO3)(I4O11): Explorations of Second-Order Nonlinear Optical Materials in the Alkali-Earth Polyiodate System.

Two new barium polyiodate compounds in the alkali-earth system, namely, HBa2.5(IO3)6(I2O5) ( Fdd2) and HBa(IO3)(I4O11) ( P1̅) have been obtained through hydrothermal reaction. Interestingly, the structures of both compounds feature different polyiodate groups, i.e., I2O5 and I4O11 groups. HBa2.5(IO3)6(I2O5) can be depicted as an alternative stacking of two-dimensional (2D) [Ba4(IO3)8(I2O5)2] and [Ba(IO3)4(I2O5)2]2- layers with the I2O5 and IO3 group serving as linkers. HBa(IO3)(I4O11) can be depicted as a 3D network with 2D [Ba(I4O11)] layers being interconnected by IO3 groups. The 0D I4O11 polyiodate group can be seen also viewed as formed by an I3O8 group further corner-sharing with an IO3 group or an I2O5 group further corner-sharing with two IO3 groups. Powder second harmonic generation (SHG) measurements show that HBa2.5(IO3)6(I2O5) crystals display a moderate SHG efficiency of ∼1.6 times that of KH2PO4 (KDP) and are phase-matchable. Optical properties measurements, thermal analyses, and laser damage threshold (LDT) measurements have been performed. Results of theoretical calculation show that the formation of I4O112- is thermodynamically much easier than I3O8- and I2O5, because of the lower reaction energy. Our studies shed light on exploring alkali-earth polyiodates as potential NLO materials.

Ce(IO3 )2 F2 ⋅H2 O: The First Rare-Earth-Metal Iodate Fluoride with Large Second Harmonic Generation Response.

The first rare earth metal iodate fluoride, Ce(IO3 )2 F2 ⋅H2 O, was synthesized by a hydrothermal method. In the structure, CeO5 F4 polyhedra connect with isolated IO3 groups to form 1D infinite [Ce(IO3 )2 F2 ] chains, which interconnect with each other by weak hydrogen bonds to construct the whole structure. Ce(IO3 )2 F2 ⋅H2 O 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 )2 F2 ⋅H2 O is a new iodate fluoride with novel structure and potential applications in nonlinear optics.

A Series of Mixed-Metal Germanium Iodates as Second-Order Nonlinear Optical Materials

A series of new compounds in the A/Ae-Ge4+-IO3 system, namely, A2Ge(IO3)6 (A = Li, Na, Rb, or Cs) and BaGe(IO3)6(H2O), have been obtained by introducing GeO6 octahedra into a ternary metal iodate system. The structures of all five new compounds feature a zero-dimensional [Ge(IO3)6]2– anion composed of a GeO6 octahedron connecting with six IO3 groups, the alkali or alkali-earth cations acting as spacers between these anions and maintaining charge balance. Interestingly, the isomeric Li2Ge(IO3)6 and Na2Ge(IO3)6 are noncentrosymmetric (NCS), whereas the isostructural Rb2Ge(IO3)6 and Cs2Ge(IO3)6 are centrosymmetric. BaGe(IO3)6(H2O) is the first NCS alkali-earth germanium iodate reported. Powder second-harmonic generation (SHG) measurements show that Li2Ge(IO3)6, Na2Ge(IO3)6, and BaGe(IO3)6(H2O) crystals are phase-matchable and display very large SHG signals that are approximately 32, 15, and 12 times that of KH2PO4, respectively, under 1064 nm radiation and 2, 0.8, and 0.8 times that of KTiOPO4, respectively,...

M(IO3)(HPO4)(H2O) (M = Sc, Fe, Ga, In): Introduction of Phosphate Anions into Metal Iodates

The first series of metal phosphate iodates, namely, M(IO3)(HPO4)(H2O) (M = Sc 1, Fe 2, Ga 3, In 4), have been obtained through hydrothermal syntheses. The title compounds are isomorphic and crystallize in the monoclinic space group C2/c (No. 15). Their structures feature a three-dimensional (3D) network composed of 1D [M(HPO4)(H2O)]+ chains that are further bridged by IO3 groups, forming 1D tunnels based on eight-membered rings along the b-axis. Magnetic measurements revealed antiferromagnetic coupling interactions between magnetic centers in compound 2. The UV absorption spectra measurements revealed that compound 2 exhibits a broad absorption peak at about 427 nm. The TGA studies and IR spectra for compounds 1–4 were also performed.

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

AbstractThe 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.

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 KH2 PO4 (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.

Macroscopic polarity control with alkali metal cation size and coordination environment in a series of tin iodates

The IO3 groups in Na2Sn(IO3)6 are aligned in a parallel manner attributed to the six-coordinate Na+ cation, whereas the IO3 polyhedra in Cs2Sn(IO3)6 rotate with respect to Sn4+ due to the nine-coordinate Cs+ cation.