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

Aug 16, 2017 - M(IO3)(HPO4)(H2O) (M = Sc, Fe, Ga, In): Introduction of Phosphate Anions into Metal Iodates. Tong-Ying Chang†‡ ... and Jiang-Gao Ma...
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M(IO3)(HPO4)(H2O) (M = Sc, Fe, Ga, In): Introduction of Phosphate Anions into Metal Iodates Tong-ying Chang, Bing-Ping Yang, Chun-Li Hu, Dong Yan, and Jiang-Gao Mao Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.7b00924 • Publication Date (Web): 16 Aug 2017 Downloaded from http://pubs.acs.org on August 16, 2017

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M(IO3)(HPO4)(H2O) (M = Sc, Fe, Ga, In): Introduction of Phosphate Anions into Metal Iodates Tong-Ying Chang, a,b Bing-Ping Yang,a Chun-Li Hu, a Dong Yan,a,b and Jiang-Gao Mao *a a

State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the

Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China. b

University of the Chinese Academy of Sciences, Beijing 100039, P. R. China.

ABSTRACT: 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 8-membered-rings (MRs) along 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.

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▇ INTRODUCTION During the past decades, abundant research attentions have been devoted to metal iodates due to their rich structural chemistry and potential applications in the areas of ferroelectricity, piezoelectricity, pyroelectric, and optical properties.1-3 Metal iodates can form a diversity of unusual and NCS structures because of the presence of stereo-chemically active lone-pair electrons on I(V) atom which can lead to the formation of numerous non-centrosymmetric compounds which are important for Second-Harmonic-Generation (SHG). I(V) cations can form isolated IO3- and IO43- groups, which can be further interconnected into I2O5 dimer or I3O8- anions, etc.4-6 The researches on metal iodates have afforded a large number of compounds with larger SHG responses, including KIO3 (200 × α-SiO2),[7a] β-Rb(IO3)(HIO3)2 (1.5 × KDP),[7b] La(IO3)3 (400 × α-SiO2),[7c] α-AgI3O8 andβ-AgI3O8 (9.0 and 8.0 × KDP).8 Furthermore, the introduction of fluoride anion into metal iodates can form two types of compounds which can also display large SHG responses: metal fluoroiodates with I-F bonds including RbIO2F2 (4 × KDP),9-10a KIO2F2 (unknown)10b and

metal iodate fluorides such as Bi(IO3)F2 (11.5 × KDP).10c

For the design and syntheses of new polar materials based on metal iodates, cations

susceptible

to

second-order

Jahn-Teller

(SOJT)

distorted

d0

transition-metal cations (e.g., Mo6+, V5+, Ti4+), polar displacement of d10 cation, and lone-pair cations (e.g., Pb2+, Bi3+) have been also introduced into metal iodate systems.11-13 Many new SHG materials have been developed such as Zn2(VO4)(IO3) (6 × KDP),14a LiMoO3(IO3) (4 × KDP),14b BiO(IO3) (12.5 × KDP)14c and Bi2(IO4)(IO3)3 (5 × KDP).14d Recently, metal iodates containing tetrahedral XO4 (X = S, Se, etc) groups have attracted much attention. A few such compounds have been reported, including Bi2O(XO4)(IO3)2 (X = S, Se)15a and Th(IO3)2(SeO4)(H2O)3H2O.15b The structure of Th(IO3)2(SeO4)(H2O)3H2O contains two-dimensional porous sheets and occluded water molecules.

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Bi2O(XO4)(IO3)2 (X = S, Se) exhibit three-dimensional frameworks that are composed of [Bi4O2]8+ clusters, IO3- and XO42- (X = S, Se) groups. It is well-known that phosphate anions can exist as PO43-, PO2(OH)2- or PO3(OH)2- groups under different conditions. Furthermore phosphate groups can be condensed into different polynuclear PxOy groups, [PO3]∞ infinite chains, or networks, which have greatly enriched the structural chemistry of metal phosphates.16-17 Metal phosphates are generally rigid, resistant to chemical attack and thermally stable. In addition, many phosphates including KH2PO4 (KDP) and KTiOPO4 (KTP) are important SHG materials.18 Thus, it is assumed that the combination of IO3- and PO43- anions into a same compound may lead to new types of metal iodates with novel structures and unique physical properties.19 To the best of our knowledge, no compounds in the M-I(V)-P(V)-O systems has been reported. Our systematic studies in trivalent metal phosphate iodate systems led to the discovery of M(IO3)(HPO4)(H2O) (M = Sc 1, Fe 2, Ga 3, In 4). Herein, we reported their syntheses, structures, magnetic and optical properties.

▇ EXPERIMENTAL SECTION

Materials and methods. All of the chemicals were analytically pure from commercial sources and used without further purification. Sc2O3 (Aladdin, 99.99%), Fe2O3 (Aladdin, 99.99%), Ga2O3 (Aladdin, 99.99%), In2O3 (Aladdin, 99.99%), I2O5 (Shanghai Reagent Factory, 99.5%), H3PO4 (Shanghai Reagent Factory, 85% solution). IR spectra were performed on a Magna 750 FT-IR spectrometer using KBr pellets from 4000 to 400 cm−1 at room temperature. Microprobe elemental analyses were performed on a field emission scanning electron microscope (FESEM, JSM6700F) equipped with an energy dispersive X-ray spectroscope (EDS, Oxford INCA). X-ray powder diffraction (XRD) patterns were collected on a Panalytical X’pert Pro MPD diffractometer using graphite-monochromated Cu-Kα radiation in

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the 2θ range of 5-75° with a step size of 0.02°. Optical diffuse-reflectance spectra were measured at room temperature with a PE Lambda 900 UV-visible spectrophotometer at room temperature with BaSO4 as the standard. The absorption spectra were calculated from reflectance spectrum using the Kubelka-Munk function: a/S = (1-R)2/2R,20 where a is the absorption coefficient, S is the scattering coefficient, which is practically wavelength-independent when the particle size is larger than 5 mm, and R is the reflectance. Thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC) curves were measured on a NETZCH STA 449C instrument with a heating rate of 10 °C/min under nitrogen atmosphere from 30 to 1000 °C. A PPMS-9T magnetometer was used to accomplish the magnetic susceptibility tests in the range of 2-300 K at 1000 Oe field. The raw data were corrected for the susceptibility of the container and the diamagnetic contributions of the sample using Pascal constants.21 Preparation of M(IO3)(HPO4)(H2O) (M = Sc 1, Fe 2, Ga 3, In 4). Single crystals of the title compounds were obtained by hydrothermal reactions of a mixture of M2O3 (Sc2O3, Fe2O3, Ga2O or In2O3), I2O5 and H3PO4 in 4 mL of water sealed in an autoclave equipped with a Teflon liner (23 mL). The loaded compositions are as follows: Sc2O3 (0.114 g, 0.82 mmol), I2O5 (0.35 g, 3.05 mmol), H3PO4 (2 ml) for compound 1; Fe2O3 (0.041 g, 0.26 mmol), I2O5 (0.35 g, 3.05 mmol), H3PO4 (2 ml) for compound 2; Ga2O3 (0.306 g, 0.56 mmol), I2O5 (0.35 g, 3.05 mmol) and H3PO4 (2 ml) for compound 3; and In2O3 (0.33 g, 0.40 mmol), I2O5 (0.35 g 3.0 mmol) and H3PO4 (2 ml) for compound 4. The mixtures were heated at 230 °C for three days and then cooled to 40 °C at a rate of 3.5 °C/h before the furnace was switched off. Colorless prismatic crystals of 1, 3 and 4, and light yellow prismatic crystals of 2 were obtained in a yield of ca. 78%, 50%, 80%, and 83% based on the M (M = Sc 1, Fe 2, Ga 3, In 4), respectively. The initial and final pH values of the reaction media are about 0.5 and 2.0, respectively for compounds 1-4. The purities of the four compounds were confirmed by powder XRD data (Figure S1). The average molar ratios of

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M/I/P (M = Sc 1, Fe 2, Ga 3, In 4) determined by energy-dispersive spectrometry (EDS) are 1.17: 1.05: 1.0, 0.75: 1.28: 1.0, 1.06: 0.86: 1.0, and 0.87: 0.80: 1.0 for compounds 1-4, respectively, which are close to those determined from single-crystal X-ray structural studies. IR data (Figure S2) (KBr cm-3): 3338 (m), 3235(m), 2813(m), 2393(w), 2303(w), 1640(m), 1382(m), 1241(s), 1161(s), 1083(s), 935 (m), 782 (s), 746(s), 619(m), 535 (s), 451(s) for compound 1; 3298(m), 3223(m), 2723(m), 2382(w), 2298(w), 1635 (m), 1382(m), 1215(s), 1166(s), 1077(s),930(s), 767(s), 608(m), 504(m), 482(m) for compound 2; 3335(s), 3326(m), 2737(m), 2439(w), 2317(m), 1644(s), 1464(w), 1388(w), 1227(s), 1090(s), 947(s), 774(s), 628(m), 506(s), 483(m) for compound 3; 3345(s), 3236(m), 2744(m), 2393(w), 2293(w), 1631(s), 1443(w), 1382(w), 1216(s), 1164(s), 1064 (s), 930(m), 784(s), 733(s), 608(m), 514(m), 450(m) for compound 4. Single crystal-structure determination. Data collections for the four compounds were collected by using SuperNova X-ray Source, Mo-Kα/Cu radiation at 298 K. The data sets were corrected for Lorentz and polarization factors as well as for absorption by SADABS program.22 All of four structures were solved by direct methods and refined by full-matrix least-squares fitting on F2 using SHELX-97.23 All of the non-hydrogen atoms were refined with anisotropic thermal parameters. All of H atoms are located at geometrically calculated positions and refined with isotropic thermal parameters. All structural data were also checked for possible missing symmetry with the program PLATON, and no higher symmetry was found.24 Crystallographic data and structural refinements for the four compounds are summarized in Table 1. Important bond lengths and angles are listed in Tables 2 and S1, respectively. Table 1. Summary of crystal data and structural refinements for the four compounds. NO. 1 2 3 4 Fw 333.85 344.74 358.63 403.73 crystal Monoclinic Monoclinic Monoclinic Monoclinic system space group C2/c C2/c C2/c C2/c a/Å 18.368(8) 18.0017(17) 17.8402(13) 18.0899(12)

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b/Å 5.8223(17) 5.6924(5) 5.6808(4) c/Å 12.861(3) 12.5064(10) 12.3273(8) β(deg) 100.574(19) 100.758(8) 100.775(7) V/Å3 1352.1(8) 1259.04(19) 1227.30(15) Z 8 8 8 -3 Dc(g.cm ) 3.280 3.637 3.882 1.075 1.048 1.057 GOF on F2 R1,wR2[I > 0.0196, 0.0500 0.0235, 0.0571 0.0417, 0.1004 a 2σ(I)] R1, wR2 (all 0.0242, 0.0517 0.0260, 0.0589 0.0460, 0.1052 data) a R1= ∑||Fo|-|Fc||/∑|Fo|, wR2 = {∑w[(Fo)2-(Fc)2]2/∑w[(Fo)2]2}1/2

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5.8883(4) 12.7958(9) 100.30(7) 1343.82(16) 8 3.997 0.995 0.0233, 0.0507 0.0267, 0.0527

Table 2. Selected bond lengths (Å) for compounds 1-4. Compounds 1 2 3 Bond length M(1)-O(5)#1 2.015(2) 1.913(3) 1.890(5) M(1)-O(4)#2 2.042(2) 1.948(3) 1.904(4) M(1)-O(1)#3 2.111(2) 2.023(3) 2.007(5) M(1)-O(6) 2.102(2) 2.017(3) 1.983(5) M(1)-O(1W) 2.135(2) 2.026(3) 1.971(5) M(1)-O(2) 2.157(2) 2.053(3) 2.020(4) I(1)-O(1) 1.816(2) 1.822(3) 1.823(4) I(1)-O(2) 1.822(2) 1.832(2) 1.835(4) I(1)-O(3) 1.795(2) 1.794(3) 1.792(5) P(1)-O(4) 1.515(2) 1.515(3) 1.520(4) P(1)-O(5) 1.508(2) 1.502(3) 1.496(5) P(1)-O(6) 1.521(2) 1.528(3) 1.527(5) P(1)-O(7) 1.572(2) 1.561(3) 1.565(5) Symmetry transformations used to generate equivalent atoms: #1 -x, y, -z+1/2; #2 x, -y+1, z-1/2; #3 -x+1/2, y-1/2, -z+1/2.

4 2.069(3) 2.082(3) 2.161(3) 2.135(3) 2.153(3) 2.192(3) 1.820(3) 1.825(3) 1.789(3) 1.512(3) 1.503(3) 1.524(4) 1.570(3)

▇ RESULTS AND DISCUSSION

A series of metal phosphate iodates, namely, M(IO3)(HPO4)(H2O) (M = Sc 1, Fe 2, Ga 3, In 4) have been prepared by hydrothermal methods. They represent the first series of metal iodates containing tetrahedral phosphate groups. It should be noted that M2O3 (M = Sc 1, Fe 2, Ga 3, In 4) and I2O5 were used as

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the metal and iodine sources for all the compounds, respectively. The crystal structures of M(IO3)(HPO4)(H2O) (M = Sc 1, Fe 2, Ga 3, In 4) 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 8-membered-rings

(MRs)

along

b-axis.

Furthermore,

they

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 8-membered-rings (MRs) along b-axis. Crystal structures. M(IO3)(HPO4)(H2O) (M = Sc 1, Fe 2, Ga 3, In 4) are isomorphic and crystallize in the space group C2/c. Their different structures are mainly due to the cation size effect.25 Therefore, only the structure of compound 2 will be discussed in detail as a representative. The asymmetric unit contain one Fe3+ cation, one IO3- anion, one [(PO3)(OH)] group and an aqua ligand. The Fe3+ cation is octahedrally coordinated by six O atoms from three [(PO3)(OH)] tetrahedra, two IO3 groups, and one aqua ligand with Fe-O bond lengths ranging from 1.913 (3) to 2.053 (3) Å and O-Fe-O bond angles in the range of 80.07 (11)-176.81 (12)º (Tables 2 and S1), hence the octahedron is slightly distorted (Figure 1a). The I(V) atom is coordinated by three O atoms to form IO3 groups with I-O bond lengths ranging from 1.794 (3) to 1.832 (2) Å. The phosphorus atom is tetrahedrally coordinated by three O2- atoms and one OH group with P-O bond lengths ranging from 1.515 (3) to 1.561 (3) Å, among which P-OH bond is the longest one (Table 2). O(7) atom is assumed to be protonated due to its long P-O distance as well as its bond valence value of -1.11 if it is assumed to be non-protonated.26 All of these bond distances and angles are comparable to those reported for other related compounds.27 The calculated total BVS values are 3.18, 4.94 and 4.94 for Fe(1), I(1) and P(1) respectively, hence Fe, I and P atoms are in oxidation states of +3, +5 and +5, respectively.28 The Fe3+ ions are interconnected by the [PO3(OH)] tetrahedra into a 1D ladder-like [Fe(HPO4)]+ chain along the c-axis. On the other hand, the

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interconnection of the metal centers by the iodate groups resulted in a 1D zigzag [Fe(IO3)]2+ chain along the b-axis (Figure 1b). The above two types of chains are further interconnected by sharing iron(III) ions to form a 3D network structure with 1D channels of Fe4I2P2 8-membered-rings (MRs) along b-axis and 1D channels of Fe2I4P4 10-membered-rings (MRs) along c-axis (Figures 1c and 1d). The iodate group is bidentate and bridges with two iron(III) ions whereas the hydrogenphosphate group is tridentate and bridges with three iron(III) ions, O(3) of the iodate group and O(7) of the PO3(OH) group remain non-coordination (Figure S2). Strong hydrogen bonds exist among O(7), O(1w) and non-coordination oxygen atom of the iodate group (O(3) [O(7)-H(7)···O(3) 2.605

(3)

Å,

167.2°;

O(1W)-H(1WA)···O(1)

2.857

(3),

159.4°;

O(1W)-H(1WB)···O(7) 2.736(3), 167.4°], which further stabilize the structure (Table S2). It is observed that the hydrogen bonds among P-OH, O(1w) and O(3) become stronger with the increase of the metal ionic radii (Table S2). In addition, the M-O bond lengths vary from 1.890 (5) to 2.069 (3) Å, O(5)-M(1)-O(4) bond angles vary from 96.46 (19) to 99.68 (12) °, and

unit

cell volumes (V) vary from 1227.30 (15) to 1343.82 (16) Å3 as well (Tables 1 and 2). However, the I-O and P-O bond lengths remain almost unchanged with different trivalent metal ions used. Because both Fe(IO3)(HPO4)(H2O) and Bi2O(SO4)(IO3)2 (P21/n) contain IO3 and XO4 (X = P or S) groups, it is worthwhile to compare their structures. In Bi2O(SdO4)(IO3)2, the five-coordination Bi(1) atoms and four-coordination Bi(2) atoms are interconnected by oxygen atoms to form a very compact structural unit [Bi4O2]8+. The rhomboidal [Bi4O2]8+ clusters are further bridged by the [SO4]2- tetrahedra to form a [Bi4O2(SO4)2]4+ chain along c-axis. These bismuth sulfate chains are then interconnected by I(2)O3 groups to form a [Bi4O2(SO4)2(IO3)2]2+ layer. Ultimately, these 2D layers are linked by I(1)O3 groups into a 3D framework structure with 1D 8-membered-rings (MRs) tunnels along c-axis.29

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. Figure 1 The coordinaton geometry around the Fe3+ in Fe(IO3)(HPO4)(H2O) (a); 1D ladder-like [Fe(HPO4)]+ chain along the c-axis and 1D zigzag [Fe(IO3)]2+ chain along the b-axis (b); view of the 3D network of Fe(IO3)(HPO4)(H2O) down the b-axis (c); and view of the 3D network of Fe(IO3)(HPO4)(H2O) down the c-axis (d). TGA and DSC studies. To investigate the thermal behavior of compounds 1-4, TGA and DSC curves were measured under a nitrogen atmosphere (Figure 2). They exhibit two similar steps of weight losses. The first weight loss of about 7.91%, 5.51%, 7.51%, and 7.25% in the range from 100-386 °C, 235-348 °C, 257-425 °C, and 250-478 °C, respectively for compounds 1-4 corresponds to the loss of 1.5 H2O molecule (the aqua ligand and water released by condensation of P-O-H groups) per formula unit. The observed weight losses are close to the calculated values of 8.00%, 6.37%, 7.60%, and 6.69%, respectively. The endothermic peaks at around 335, 322, 285 and 324 °C, respectively for 1-4 can be found in the DSC curves. After dehydration, TGA

the

of compounds 1-4 display the second weight losses of about 52.06%,

50.09%, 45.91%, and 40.98% respectively in the range from 386-858 °C, 348-692 °C, 425-513 °C, and 478-732 °C, respectively for compounds 1-4, which corresponds to the loss of 2.5 O2, and 0.5 I2 molecule per formula unit

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(calculated values are 49.99%, 49.88%, 46.54%, and 41.35%, respectively). The endothermic peaks at around 528, 437, 418 and 522 °C can be found in the DSC curves, respectively. The residuals were confirmed by the powder XRD data to be the corresponding ScPO4, FePO4, GaPO4, and InPO4, respectively (Figure S3).30 The observed total mass losses of 59.97%, 55.60%, 53.42%, and 48.23% for compounds 1-4, are very close to the calculated values of 57.99 %, 56.25%,

54.14%,

and

decomposition reaction

48.04%,

respectively.

can

be

Thus,

the

described

thermal as:

M(IO3)(HPO4)(H2O)-1.5H2O-2.5O2-0.5I2 = MPO4.

Figure 2. TGA-DSC curves of compounds 1 (a), 2 (b), 3 (c), and 4 (d). UV and IR spectra. UV-vis absorption spectra measurements revealed that compounds 1, 3 and 4 are transparent in wavelength region of 1500-400 nm. However, compound 2 exhibits a broad absorption peak at about 427 nm, which is derived from the characteristic d-d transition associated with Fe3+ ions. Optical diffuse

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reflectance spectra show that compounds 1-4 are wide band gap semiconductors with band gaps of 3.01, 3.56, 4.21, and 4.26 eV, respectively (Figure 3).

Figure 3. UV-vis Optical absorption spectra for compounds 1 (a), 2 (b), 3 (c), and 4 (d). The IR absorption peaks around 3400 and 1600 cm-1for 1-4 are due to H-O stretching and bending vibration, respectively. The absorption bands centered at 782, 746 and 619 cm-1 for 1 and 767 and 608 cm-1 for 2 and 774, 628 cm-1 for 3 and 784, 733 and 608 cm-1 for 4 could be attributed to the symmetrical and asymmetrical stretching mode of I-O vibrations. The absorption bands centered at 1382,1241, 1161, 1083 and 935 cm-1 for 1and 1382, 1215, 1166, 1077, 930, 504 and 482 cm-1 for 2 and 1464, 1388, 1227, 1090, 947, 506 and 483 cm-1 for 3 and 1443, 1382, 1216, 1164, 1064, 930, 608, 514, and 450 cm-1 for 4 could be attributed to P-O vibrations. These assignments are in good agreement with those reported in other related compounds.31 Magnetic properties. The magnetic properties of compound 2 have been measured in the temperature region from 2 to 300 K at a magnetic field of 1000

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Oe. Plots of the molar magnetic susceptibility (χ) and corresponding reciprocal susceptibility (χ-1) versus temperature (T) are shown in Figure 4. For compound 2, the magnetic susceptibility data can be fitted to the Curie-Weiss law over a wide temperature range, that is, 50-300 K, χ = C/(T-θ), C = NA(ueff)2/3k, where C is the Curie constant, θ is the Weiss constant, NA is the Avogadro’s number, ueff is the effective magnetic moment, and k is the Boltzmann’s constant. At 300 K, the effective magnetic moment of Fe3+ ions in the system was calculated to be 5.51 uB, which agrees with that theoretically expected for an isolated Fe3+ in a high-spin state. The Weiss constant θ is found to be -50.5 K, which is indicative of a significant antiferromagnetic interaction between neighboring Fe3+ ions, which is also confirmed by the observed maximum around 27 K in the χ-T plot. The structure of compound 2 contains two types of super-super-exchange routes: Fe-O-P-O-Fe and Fe-O-I-O-Fe with Fe... Fe separations of 4.5937 and 5.9934 Å, respectively. It can be concluded that there is still significant antiferromagnetic interaction between neighboring Fe3+ ions in spite of large Fe…Fe separations.

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Figure 4. Plots of χ and 1/χ vs T for compound 2, the red lines represent the linear fit of data according to the Curie-Weiss Law.

▇ CONCLUSION In summary, the first series of metal phosphate iodates, namely, M(IO3)(HPO4)(H2O) (M = Sc 1, Fe 2, Ga 3, In 4) have been prepared through a facile hydrothermal synthetic route. Their structures feature 3D network structures composed of 1D [M(HPO4)(H2O)]+ chains that are further bridged by IO3 groups forming 1D tunnels based on 8-membered-rings (MRs) along b-axis. The magnetic susceptibility data indicate the existence of antiferromagnetic ordering in compound 2. This study provides a new approach to design and synthesize new metal iodates. Our future research efforts will be devoted to the introduction of Bi3+ and Ln3+ cations into the phosphate iodates systems. Bismuth(III) ion is a heavy metal cation containing a lone electron pair, which in combination with the iodate anion may lead to both a large SHG response and a wide transparency range. Lanthanide ions can be widely applied in the field of fluorescence and laser application due to their unusual spectral characters. Thus, we think that the introduction of Bi3+ / Ln3+ may lead to a number of new metal iodates with novel structures and unique optical or magnetic properties. ▇ ASSOCIATED CONTENT Supporting Information The Supporting Information is available free of charge on the ACS Publications website. X-ray crystallographic files in CIF format (CCDC 1543846-1543849), X-ray powder diffraction patterns, IR spectra, selected bond angles, and hydrogen bonds for compounds 1-4. The measured XRD powder patterns of the calcinates in compounds 1-4 compared with the simulated ones of ScPO4 (a), FePO4 (b), GaPO4 (c), and InPO4 (d). The coordination modes of the iodate and phosphate anions in Compound 2.

▇ AUTHOR INFORMATION

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Corresponding Author *E-mail: [email protected] ▇ ACKNOWLEDGMENTS

Our work was supported by National Natural Science Foundation of China (Grants Nos. 21231006, 21373222, and 21003127).

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For Table of Contents Use Only b

a Fe I P O H

c

The first series of metal phosphate iodates, namely, M(IO3)(HPO4)(H2O) (M = Sc, Fe, Ga, In), have been reported here.

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