2 (Ln = Y, Sm, Eu, Gd, Dy): A Series of Lanthanide ... - ACS Publications

Jun 6, 2016 - Synopsis. The first examples of mixed-anion lanthanide galloborates, namely, Ln2Ga[B3O6(OH)]2[B7O9(OH)2](CH3CO2)2 [Ln = Y (1), Sm (2), ...
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Ln2Ga[B3O6(OH)]2[B7O9(OH)2](CH3CO2)2 (Ln = Y, Sm, Eu, Gd, Dy): A Series of Lanthanide Galloborates Decorated by Acetate Anions Hui Yang,†,‡ Chun-Li Hu,† and Jiang-Gao Mao*,† †

State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China ‡ University of the Chinese Academy of Sciences, Beijing 100039, P. R. China S Supporting Information *

ABSTRACT: The first examples of mixed-anion lanthanide galloborates, namely, Ln2Ga[B3O6(OH)]2[B7O9(OH)2](CH3CO2)2 [Ln = Y (1), Sm (2), Eu (3), Gd (4), Dy (5)], have been obtained through hydrothermal synthesis. The title compounds are isomorphic and belong to monoclinic space group C2/c (No. 15). Their structures possess [B7O13(OH)2] borate layers further bridged with [B3O7] clusters to give a three-dimensional (3D) borate framework displaying two types of rhombus-like B14O14 14membered-ring (14-MR) channels along the b axis. The Ga3+ ions are octahedrally coordinated and located at one end of the B14O14 14-MR channels, forming small tunnels of B7Ga 8-MRs, which are filled by the LnIII ions. The Ln ions and Ga cations are further held together by bridging acetate anions. It is worth noting that in these compounds there are two different types of borate clusters and two types of anions that are uncommon in the borates reported. Luminescent studies revealed the characteristic emission bands of Ln ions for compounds 2−5, and the luminescent lifetimes are 3.6, 0.86, and 3.05 ns for compounds 2, 3, and 5, respectively. Magnetic measurements suggest that there are antiferromagnetic interactions between magnetic centers for compounds 2−5.

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under excitation of 370 nm,14c Ba3Ga2[B3O4(OH)]2[B4O7(OH)2] shows a large SHG coefficient of about 3 times that of KH2PO4,14d and Ga2B3O7(OH) could split water photocatalytically.14e The scarcity of galloborates reported can be attributed to the difficulty in their syntheses and the fact that their single crystals are difficult to obtain. We deem that carboxylate ligands such as the CH3COO− anion could be introduced to metal galloborates to get novel hybrid compounds that can not only have better crystallinity and exhibit richer structural chemistry but also display new optical properties.16,17 The CH3COO− anions have been successfully grafted into the lanthanide borate system by our group, and a series of new mixed-anion compounds with moderate SHG signals, Ln2(CH3CO2)2[B5O9(OH)]·H2O (Ln = La, Ce, Pr), were isolated.18 The CH3COO− anions not only act as the metal linkers but also made an important contribution to the strong SHG signals observed because of the existence of π-conjugated electrons.18 Being an extension for our previous works, we try to introduce CH3COO− anions into the lanthanide galloborates in order to get new inorganic− organic hybrids in this study. Systematic researches led to the first series of novel mixed-anion lanthanide galloborates, namely, Ln2Ga[B3O6(OH)]2[B7O9(OH)2](CH3CO2)2 [Ln = Y (1), Sm (2), Eu (3), Gd (4), Dy (5)]. Herein, we report the

INTRODUCTION Borates have been a highly explored topic of research interest because they exhibit a wide range of unique structural features and practical applications in optics, molecular sieves, catalysts, and magnetism.1−5 On the basis of the structural point of view, three- or four-coordinated B3+ cations can form various polyborate clusters ranging from [B2O5]4− to [B18O36]18−.6−9 These B−O groups are also able to combine with various heteroatoms, which afforded a series of new compounds with interesting architectural features and distinct properties such as borogermanate,10 borophosphate,11 borosulfate, etc.12 One of such types of materials is galloborates, which exhibit rich structural chemistry because the Ga3+ cation can adopt flexible coordination geometries including tetrahedral GaO4, trigonalbipyramidal GaO5, and octahedral GaO6.13 To the best of our knowledge, studies about galloborates are still in their infant stage. A few simple inorganic galloborates are reported including K2Ga2O(BO3)2, Ba4Ga2B8O18Cl2, Ba[GaB4O8(OH)]·H2O, Ba3Ga2[B3O4(OH)]2[B4O7(OH)2], and Ga2B3O7(OH).14 Only one galloborate with a coordinated organic amine, namely, [Ga(en)2][B5O8(OH)2]·H2O, has been reported.15 These materials display a range of structures including chains, layers, and three-dimensional (3D) frameworks.14,15 These galloborates also display many important physical properties such as luminescence, second harmonic generation (SHG), photocatalytic activity, etc. For example, Ba[GaB4O8(OH)]·H2O exhibits strong emission at 437 nm © XXXX American Chemical Society

Received: March 8, 2016

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DOI: 10.1021/acs.inorgchem.6b00584 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry Table 1. Crystal Data and Structure Refinements for Five Compounds formula fw space group a [Å] b [Å] c [Å] α [deg] β [deg] γ [deg] V [Å3] Z Dcalcd [g/cm3] μ [mm−1] F(000) GOF on F2 R1, wR2 [I > 2σ(I)]a R1, wR2 (all data) a

1

2

3

4

5

C4H10B13O29GaY2 910.19 C2/c 19.1440(5) 8.5429(2) 17.2441(5) 90 105.945(3) 90 2711.69(12) 4 2.229 7.893 1760 1.145 0.0668, 0.1530 0.0701, 0.1583

C4H10B13O29GaSm2 1033.07 C2/c 19.3137(8) 8.6078(4) 17.3343(8) 90 105.671(5) 90 2774.7(2) 4 2.473 5.259 1944 1.185 0.0378, 0.0844 0.0416, 0.0859

C4H10B13O29GaEu2 1036.29 C2/c 19.2923(16) 8.5902(6) 17.2909(16) 90 105.636(10) 90 2759.5(4) 4 2.494 5.578 1952 1.069 0.0393, 0.0929 0.0476, 0.0984

C4H10B13O29GaGd2 1046.87 C2/c 19.2180(12) 8.5773(5) 17.2658(15) 90 105.733(8) 90 2739.4(3) 4 2.538 5.883 1960 0.977 0.0361, 0.0623 0.0505, 0.0694

C4H10B13O29GaDy2 1057.37 C2/c 19.1779(4) 8.54810(10) 17.2497(3) 90 105.882(2) 90 2719.88(8) 4 2.582 31.224 1976 1.073 0.0181, 0.0449 0.0199, 0.0459

R1 = ∑||Fo| − |Fc||/∑|Fo|; wR2 = {∑w[(Fo)2 − (Fc)2]2/∑w[(Fo)2]2}1/2. spectrometry were 2.11(2):1, 2.05(2):1, 2.16(1):1, 2.08(4):1, and 2.01(5):1 for compounds 1−5, respectively, which were in good accordance with those obtained by single-crystal structural data. Compound 1. Yield: 60% based on yttrium. Anal. Calcd for C4H10B13O29GaY2 (Mr = 910.17): C, 5.27; H, 1.10. Found: C, 5.42; H, 1.35. IR spectrum (cm−1, KBr pellet): 3442(s), 1582(s), 1419(m), 1206(s), 1065(s), 887(m), 724(m), 568(w). Compound 2. Yield: 65% based on samarium. Anal. Calcd for C4H10B13O29GaSm2 (Mr = 1033.08): C, 4.65; H, 0.97. Found: C, 4.90; H, 1.29. IR spectrum (cm−1, KBr pellet): 3439(s), 1582(s), 1422(m), 1181(s), 1057(s), 885(m), 714(m), 566(w). Compound 3. Yield: 70% based on europium. Anal. Calcd for C4H10B13O29GaEu2 (Mr = 1036.29): C, 4.63; H, 0.97. Found: C, 4.65; H, 1.25. IR spectrum (cm−1, KBr pellet): 3431(s), 1578(s), 1422(m), 1186(s), 1048(s), 883(m), 718(m), 561(w). Compound 4. Yield: 45% based on gadolinium. Anal. Calcd for C4H10B13O29GaGd2 (Mr = 1046.86): C, 4.58; H, 0.96. Found: C, 4.60; H, 1.12. IR spectrum (cm−1, KBr pellet): 3437(s), 1579(s), 1419(m), 1193(s), 1051(s), 872(m), 720(m), 570(w). Compound 5. Yield: 50% based on dysprosium. Anal. Calcd for C4H10B13O29GaDy2 (Mr = 1057.36): C, 4.54; H, 0.95. Found: C, 4.43; H, 1.15. IR spectrum (cm−1, KBr pellet): 3439(s), 1581(s), 1419(m), 1197(s), 1060(s), 877(m), 725(m), 580(w). Single-Crystal Structure Determination. Single-crystal data of the title five compounds were collected on a SuperNova X-ray source with Mo Kα/Cu radiation at 293(2) K. All data sets were corrected for Lorentz and polarization factors as well as for absorption based on the multiscan program.20a Five structural data were solved through direct methods and refined through a full-matrix least-squares fitting on F2 using the SHELX-97 program.20b All H atoms are located at geometrically calculated positions and refined with isotropic thermal parameters. All of the other atoms were refined anisotropically. All structural data were also checked for possible missing symmetry with the program PLATON, and no higher symmetry was found.20c Crystallographic data and important bond distances of all compounds have been summarized in Tables 1 and 2, respectively. Further details about the crystallographic studies and atomic displacement parameters are supplied in the Supporting Information (SI). Computational Descriptions. The electronic property calculation for compound 1 had been accomplished through the total energy code CASTEP.21 The total energy is calculated with density functional theory (DFT) using the Perdew−Burke−Ernzerhof generalized-gradient approximation.22 The interactions between the valence electrons and the ionic cores are described through the normconserving pseudopotential.23 Pseudoatomic calculations are performed for Y 4d15s25p0, Ga 3d104s24p1, B 2s22p1, O 2s22p4, C 2s22p3, and H 1s1. The number of plane waves included in the basis set

syntheses, crystal structures, thermal stabilities, and optical and magnetic properties.

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EXPERIMENTAL SECTION

Reagents and Methods. (NH4)2B10O16·8H2O (Aladdin, 99.9%), H3BO3 (Shanghai Reagent Factory, 99.9%), acetic acid (CH3COOH; Sinopharm, 99.5%), Ga(NO3)3·xH2O (Aladdin, 99.9%), and Ln2O3 (Ruike National Engineering Research Centre of Rare Earth Metallurgy, 99.99+%) were used as received. IR spectra were performed on KBr matrixes in the 400−4000 cm−1 range using a Magna 750 Fourier transform infrared spectrometer at room temperature. Powder X-ray diffraction (XRD) analysis for five compounds was obtained on a XPERT-MPD θ−2θ diffractometer equipped with Cu Kα radiation with an angular range of 2θ = 5−55° and a step width of 0.02° at room temperature. Microprobe elemental analyses have been carried out on a field-emission scanning electron microscope (JSM6700F) equipped with an energy-dispersive X-ray spectrometer (Oxford INCA). Elemental analyses for carbon and hydrogen have been supplied through a German Elementary Vario EL III instrument. Optical diffuse-reflectance spectra were recorded with the aid of a PE Lambda 900 UV−visible spectrophotometer at room temperature with BaSO4 as the standard. The Kubelka−Munk function, α/S = (1 − R)2/2R, was used to produce absorption spectra, and in the function, α is the absorption coefficient, S is the scattering coefficient, which is practically wavelength-independent when the particle size is larger than 5 μm, and R is the reflectance.19 Thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC) analyses were performed on a NETZSCH 449C thermal analyzer instrument at a heating rate of 10 °C/min under flowing nitrogen gas from 30 to 1000 °C. Photoluminescence was measured on a single-grating Edinburgh FL920 fluorescence spectrometer equipped with a R928 PMT detector. Magnetic susceptibility measurements were recorded on polycrystalline samples by a PPMS9T magnetometer at a field of 1000 Oe at temperatures ranging from 2 to 300 K. Preparation of Ln2Ga[B3O6(OH)]2[B7O9(OH)2](CH3CO2)2 [Ln = Y (1), Sm (2), Eu (3), Gd (4), Dy (5)]. Single crystals for compounds 1−5 were synthesized through hydrothermal methods of Ln2O3 (1 mmol), Ga(NO3)3·xH2O (1 mmol), H3BO3 (2 mmol), CH3COOH (6 mL), and (NH4)2B10O16·8H2O (1 mmol) in a 23 mL Teflon autoclave. The reaction reagents were heated first at 100 °C for 5 h and then held at 220 °C for 3 days, followed by slow cooling to 25 °C at a rate of 1 °C/ h. Block and colorless crystals were synthesized. The purities of all compounds are confirmed through powder XRD data (Figure S1). The atomic ratios of Ln:Ga recorded through energy-dispersive B

DOI: 10.1021/acs.inorgchem.6b00584 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry Table 2. Important Bond Lengths (Å) for Five Compoundsa Ln(1)−O(8)#1 Ln(1)−O(6)#2 Ln(1)−O(14) Ln(1)−O(3)#2 Ln(1)−O(12)#3 Ln(1)−O(10)#4 Ln(1)−O(2)#2 Ln(1)−O(4) Ln(1)−O(11)#1 mean Ln−O Ga(1)−O(8) Ga(1)−O(8)#5 Ga(1)−O(6) Ga(1)−O(6)#5 Ga(1)−O(15)#2 Ga(1)−O(15)#6 mean Ga−O B(2)−O(2) B(2)−O(2)#2 B(2)−O(3)#2 B(2)−O(3) B(6)−O(10) B(6)−O(9) B(6)−O(11) B(6)−O(12)#8 mean B−O(□) B(1)−O(13)#7 B(1)−O(1) B(1)−O(2) B(3)−O(5) B(3)−O(4) B(3)−O(3) B(4)−O(6) B(4)−O(7) B(4)−O(5) B(5)−O(8) B(5)−O(7) B(5)−O(9) B(7)−O(11) B(7)−O(13) B(7)−O(12) mean B−O(△) C(1)−O(14) C(1)−O(15) C(1)−C(2)

C4H10B13O29GaY2 (1)

C4H10B13O29GaSm2 (2)

C4H10B13O29GaEu2 (3)

C4H10B13O29GaGd2 (4)

C4H10B13O29GaDy2 (5)

2.300(4) 2.343(4) 2.367(4) 2.389(4) 2.395(3) 2.396(3) 2.478(3) 2.472(4) 2.579(3) 2.413(4) 1.936(3) 1.936(3) 1.965(4) 1.965(4) 2.010(4) 2.010(4) 1.970(4) 1.453(6) 1.453(5) 1.461(6) 1.461(6) 1.454(6) 1.455(6) 1.487(6) 1.487(6) 1.464(6) 1.351(8) 1.363(7) 1.366(8) 1.346(8) 1.375(7) 1.377(7) 1.346(7) 1.372(7) 1.391(7) 1.360(7) 1.371(7) 1.377(7) 1.374(7) 1.373(7) 1.362(7) 1.367(7) 1.247(7) 1.276(7) 1.496(9)

2.357(4) 2.382(4) 2.438(4) 2.434(3) 2.434(4) 2.442(4) 2.501(4) 2.539(4) 2.583(3) 2.457(4) 1.937(4) 1.934(4) 1.965(4) 1.965(4) 2.016(4) 2.016(4) 1.973(4) 1.450(4) 1.450(6) 1.467(6) 1.467(6) 1.442(7) 1.460(7) 1.491(7) 1.483(7) 1.464(7) 1.367(8) 1.372(8) 1.365(9) 1.345(8) 1.379(7) 1.369(7) 1.349(7) 1.373(7) 1.392(7) 1.354(7) 1.371(7) 1.379(7) 1.383(7) 1.378(8) 1.353(8) 1.369(7) 1.243(8) 1.264(8) 1.523(11)

2.349(5) 2.371(5) 2.410(5) 2.432(5) 2.432(5) 2.442(5) 2.504(5) 2.525(6) 2.587(5) 2.450(5) 1.932(5) 1.932(5) 1.968(5) 1.968(5) 2.010(5) 2.010(5) 1.970(5) 1.460(5) 1.460(9) 1.463(9) 1.463(9) 1.446(9) 1.451(10) 1.500(10) 1.487(9) 1.466(9) 1.365(11) 1.371(10) 1.358(11) 1.351(11) 1.381(11) 1.367(10) 1.344(10) 1.368(11) 1.388(11) 1.359(10) 1.384(10) 1.355(10) 1.359(11) 1.376(11) 1.366(11) 1.366(11) 1.248(10) 1.277(10) 1.505(13)

2.334(4) 2.370(4) 2.415(4) 2.413(3) 2.422(3) 2.433(3) 2.501(4) 2.509(4) 2.578(3) 2.442(4) 1.935(3) 1.935(3) 1.961(4) 1.961(4) 2.011(4) 2.011(4) 1.969(4) 1.463(4) 1.463(6) 1.454(6) 1.454(6) 1.451(7) 1.441(8) 1.470(7) 1.509(6) 1.463(7) 1.351(7) 1.385(7) 1.354(7) 1.344(8) 1.370(7) 1.370(7) 1.346(7) 1.367(8) 1.399(7) 1.347(7) 1.366(7) 1.376(7) 1.363(7) 1.376(7) 1.363(7) 1.365(7) 1.240(7) 1.281(7) 1.506(9)

2.317(2) 2.353(2) 2.380(2) 2.402(2) 2.400(2) 2.407(2) 2.490(2) 2.484(2) 2.577(2) 2.429(2) 1.934(2) 1.934(2) 1.962(2) 1.962(2) 2.014(2) 2.014(2) 1.970(2) 1.454(4) 1.454(4) 1.463(4) 1.463(4) 1.448(4) 1.457(4) 1.488(4) 1.490(4) 1.465(4) 1.350(5) 1.371(5) 1.366(5) 1.348(5) 1.368(5) 1.370(5) 1.345(5) 1.374(5) 1.387(5) 1.348(4) 1.368(4) 1.372(5) 1.364(5) 1.366(5) 1.371(5) 1.365(5) 1.245(5) 1.278(4) 1.488(6)

Symmetry transformations used to generate equivalent atoms: #1, x − 1/2, −y + 3/2, z − 1/2; #2, −x + 1, y, −z + 1/2; #3, −x + 1, −y + 2, −z + 1; #4, −x + 1, −y + 1, −z + 1; #5, −x + 3/2, −y + 3/2, −z + 1; #6, x + 1/2, −y + 3/2, z + 1/2; #7, x, −y + 2, z − 1/2; #8, −x + 3/2, y − 1/2, −z + 3/2. a

are determined by a cutoff energy of 800 eV, and a 3 × 3 × 2 Monkhorst−Pack k-point sampling is used for the numerical integration of compound 1.

asymmetric unit of compound 1 contains 1 Y, 1 Ga, 7 B, and 11 O atoms and one CH3COO− and two OH− anions, among which the Ga(1) atom is located at an inversion center, whereas the B(2) and O(1) atoms reside on the 2-fold rotation axis. In the structure, there are two types of borate units: linear [B 3 O 6 (OH)] 4 − ({B3}) and two-dimensional (2D) [B7O15(OH)2]11− ({B7}). The linear {B3} cluster is built of B(4)O3, B(5)O3, and B(3)O2(OH) units by corner-sharing. {B7} are formed by B(1)O3, B(7)O3, B(2)O4, and B(6)O3(OH) units. Two B(1)O3 and one B(2)O4 units form a B3O7 cluster via corner-sharing of O(1) and O(2) atoms, whereas corner-sharing [O(11) and O(13) atoms] between

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RESULTS AND DISCUSSION A series of hybrid lanthanide galloborate materials have been isolated by the hydrothermal method. They represent the first series of mixed-anion galloborates. Ln2Ga[B3O6(OH)]2[B7O9(OH)2](CH3CO2)2 [Ln = Y (1), Sm (2), Eu (3), Gd (4), Dy (5)] are isomorphic and belong to the space group C2/c. Therefore, only the structure of 1 will be taken as a representation to be discussed in detail. The C

DOI: 10.1021/acs.inorgchem.6b00584 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry

Figure 1. View of the single borate layer (a). 3D structure of the galloborate framework (b). Butterfly-like 14-MR in different directions (left and right) (c). View of the arrangement of two borate layers in the ab plane (d). Color code: BO4 tetrahedra, blue; BO3 triangle, purple; B, blue; O, red.

Rb2Ga(B5O10)(H2O)4.24a In GaB5O8(OH)2(en)2·H2O, neighboring Ga3+ ions are bridged by [B5O8(OH)2]3− groups to form an infinite zigzag chain and LiGa(OH)(BO3)(H2O) displays layers built of GaO4 and BO3 groups, which are alternatively interconnected by corner-sharing, whereas Rb2Ga(B5O10)(H2O)4 exhibits a 3D network, which is built by [B5O10]5− anions interconnected with GaO4 tetraheda (Figure S3). The Ga−O bond distances vary from 1.936(3) to 2.010(4) Å, and the O−Ga−O bond angles range from 85.60(15) to 180.000(1)°. All of these values are consistent with those acquired from other borates.6−12 The network topology of the galloborate framework can be simplified by considering the GaO6 octahedron and two {B3} to be 2-connected nodes and {B7} clusters as 6-connected nodes. As a result, the pcu topology with a Schläfli symbol of {412·63} is formed (Figure 2b). The charge of the anionic Ga[B3O6(OH)]2[B7O9(OH)2]6− framework is balanced through two Y3+ ions, which reside in the above B7Ga 8-MRs of the structure (Figure 2c). Each Y3+ ion is nine-coordinated by eight O atoms from the borate units and one acetate anion in a unidentate mode and the coordination geometry of the Y atom can be seen as a distorted tricapped trigonal prism. The Y−O bond distances range from 2.300(4) to 2.579(3) Å, and the O− Y−O bond angles vary from 54.82(11) to 154.62(12)°. The interconnection of a GaO6 octahedron and a YO9 poyhedron by bridging acetate anions forms [Y2GaO18(CH2COO)2]7− clusters (Figure S2c). The acetate anion is bidentate-bridging and connects with one Y atom and one Ga atom (Figure S2c). The bond-valence-sum calculations for Y(1), Ga(1), and B(1)−

B(6)O3(OH) and B(7)O3 groups led to one-dimensional (1D) borate chains along the b axis. The above borate chains are interconnected through B3O7 units via corner-sharing, resulting in the existence of the 2D [B7O13(OH)2] borate layers in the ab plane with butterfly-like B14O14 14-membered-ring (14-MR) windows, delimited by 4 BO4 and 10 BO3 groups, with a diameter of 5.02 × 9.14 Å (Figures 1a and S2e). Adjacent [B7O13(OH)2] layers arrange in an alternating direction (left and right), leading to ellipse-like channels along the c axis (Figure 1c,d). These borate layers are cross-linked by linear [B3O6(OH)]4− groups to form a 3D pillared−layered framework with two types of rhombus-like B14O14 14-MRs (A and B) channels in the ac plane (Figure 2a). In the A rings, O(6) and O(8) atoms of two sides all point to the inner part of the rings, whereas in the B rings, there are only O(4) atoms pointing to the inner part of the rings. For BO3 units, the B−O distances range from 1.346(7) to 1.377(7) Å and the O−B−O bond angles vary from 112.6(5) to 124.0(5)°. For BO4 tetrahedra, the B−O distances and O−B−O angles vary from 1.453(5) to 1.487(6) Å and from 101.0(4) to 113.6(2)°, respectively. The Ga3+ ions reside in the A channels with an interval of the B channels, and each of them forms two six-membered chelating rings with two linear [B3O6(OH)]4− groups; hence, the A channels are divided into two B7Ga 8-MRs (Figures 1b, 2c, and S2d). The remaining two coordination sites of the Ga3+ cation are filled by two CH3COO− anions (Figure S2d). The linkage of Ga with two types of borate clusters is different from that in the reported galloborates with one type of borate cluster such as GaB5O8(OH)2(en)2·H2O, LiGa(OH)(BO3)(H2O), and D

DOI: 10.1021/acs.inorgchem.6b00584 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry

Figure 2. Projections of the borate layer, showing two different 14-MR channels, A and B (a). View of the topology network of a 3D galloborate (b). 3D structure of compound 1 (c). Color code: BO4 tetrahedra, blue; BO3 triangle, purple; Ba, yellow; C, black; B, blue; O, red; H, gray.

five compounds, which indicates that lanthanide contraction also weakly affects the channels. Comparison of 1 with Ba3Ga2[B3O6(OH)]2[B4O7(OH)2]. Although these two compounds crystallize in different space groups, it is worthwhile to compare compound 1 with Ba3Ga2[B3O6(OH)]2[B4O7(OH)2]24b because the two compounds display similar structural features: two different oxoboron clusters, [B3O6(OH)] and [B7O15(OH)2] for compound 1 and [B 3O 6 (OH)] and [B 4 O7 (OH)2 ] for Ba3Ga2[B3O6(OH)]2[B4O7(OH)2], and specific connectivity between adjacent layers and borate bridges (Figure S3d). In compound 1, [B7O15(OH)2] clusters connect with four others in the borate layers with 14-MR windows, whereas in Ba3Ga2[B3O6(OH)]2[B4O7(OH)2], each [B3O6(OH)] connects to six others by three bridging GaO4 groups and vice versa, giving rise to a galloborate layer displaying 9-MR windows. Furthermore, the adjacent layers in both compounds are linked by a second kind of borate group into 3D frameworks with different unusual 14-MR channels in the two compounds. Furthermore, in compound 1, those two clusters are further linked together to form a 3D pure borate framework, whereas in Ba3Ga2[B3O6(OH)]2[B4O7(OH)2], two

B(7) atoms gave values of 3.12, 3.14, and 3.01−3.16, respectively, resulting in an oxidation state of 3+ for the Y, Ga, and B atoms.25 Furthermore, strong hydrogen bonds exist between noncoordination B−OH groups and B−O groups in the structure [O(10)−H(10A)···O(11) 2.838(5) Å, 138.6°; O(10)−H(10A)···O(8) 2.983(5) Å, 133.1°; O(4)−H(4A)··· O(9) 2.549(5) Å, 154.2°], playing an important role in stabilizing the structure. The Ln−O average bond length decreases significantly from Sm [2.457(4) Å] to Dy [2.429(2) Å] because of the so-called “lanthanide contraction” (Table 2). The three axial lengths decrease from compound 2 to compound 5, and the unit cell volumes also contract about 1.9% (Table 1). Because of the smallest ionic radius of Y, the cell volume of compound 1 is even smaller than that of compound 5. However, Ga−O and B−O bond lengths have been weakly affected by lanthanide contraction, with the average bond ranges of 1.969(4)− 1.973(4), 1.463(7)−1.466(9), and 1.365(5)−1.369(7) Å for the GaO6, BO4(□), BO3(△) groups, respectively, for the five compounds. Their structures possess solvent accessible volumes of 289.4, 301.9, 288.4, 287.0, and 287.9 Å3 and 10.7, 10.9, 10.5, 10.5, and 10.6% of the unit cells, respectively, for the E

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Figure 3. Solid-state emission spectra of compounds 1 (λex = 342 nm) (a), 2 (λex = 405 nm) (b), 3 (λex = 396 nm) (c), 4 (λex = 274 nm) (d), and 5 (λex = 353 nm) (e).

phous, and the remaining products were not further characterized. Optical Properties. The UV absorption spectral measurements reveal that compounds 1, 3, and 4 show little absorption ranging from 350 to 2000 nm. However, compound 2 exhibits characteristic sharp absorption peaks around 408, 1097, 1260, and 1400 nm, and compound 5 shows characteristic sharp absorption bands at 807, 907, 1107, and 1301 nm. Those absorption peaks are derived from the characteristic f−f or f−d transition of the Sm3+ and Dy3+ (Figure S5).26 Optical diffuse-reflectance spectra show that the optical band gaps for compounds 1−5 are 4.07, 5.20, 4.41, 5.10, and 5.03 eV, respectively, which imply that they are insulators. For these isostructural compounds, the differences among the band gaps can be attributed to different electronic configurations of the Ln3+ ions (Figure S5).

types of borate clusters are connected by GaO4 tetrahedra, acting as linkers to form a novel 3D framework. TGA Studies. To investigate the thermal behavior of compounds 1−5, TGA and DSC curves were measured under a nitrogen atmosphere (Figure S4). It is clearly noted that the TGA curves show weight losses in only one step in temperatures ranging from 30 to 1000 °C for all compounds. The strong weight losses are at 300−750, 360−800, 390−710, 340−810, and 315−780 °C for compounds 1−5, respectively, indicating decomposition of the borate and CH3COO− units, and an endothermic peak in every DSC curve is clearly observed around 566 °C. The total weight losses are 15.68, 13.41, 13.97, 13.28, and 13.27% for compounds 1−5, respectively, which correspond to the calculated ones (16.93, 14.91, 14.87, 14.72, and 14.57% for compounds 1−5, respectively). Upon calcination, all compounds were amorF

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Figure 4. Plots of χ and 1/χ versus T for compounds 2 (a), 3 (b), 4 (c) and 5 (d). The red lines represent the linear fit of data according to the Curie−Weiss law.

All five compounds are isostructural, resulting in similar IR spectra (Figure S6). They exhibit broad IR absorption bands centered around 3440 cm−1 because of the existence of OH groups. The absorption peaks from 1578 to 1582 cm−1 are because of the asymmetric stretching vibration of COO− anions. However, the absorption bands around 1420 cm−1 could not be assigned unambiguously because of the overlap of the symmetric stretching of COO− and asymmetrical stretching of the BO3 clusters. The absorption peaks ranging from 1050 to 1200 cm−1 could be associated with the BO4 tetrahedra, and the bands are split into two peaks around 1190 and 1050 cm−1 because of distortion of the tetrahedral BO4 cluster from ideal Td symmetry removing the degeneracy of the IR-active asymmetric stretching vibration. The peaks around 880 cm−1 are associated with the symmetric stretching vibration of the BO3 units, and the peaks ranging from 710 to 730 cm−1 can be attributed to the symmetric stretching vibration of the BO4 units. Because of the overlaps of the bending modes of BO4 and GaO4 polyhedra, vibration absorption peaks below 600 cm−1 are difficult to assign undoubtedly. These assignments are matchable with those occurring in other compounds.6−13 Luminescent Properties. The fluorescent spectra of compounds 1−3 and 5 were measured at 298 K, and that of compound 4 was measured at 77 K (Figure 3). For compound 1, there is a broad band at 394 nm from the fluorescent spectrum under excitation of 342 nm. Its blue emission is similar to that of the luminescent borates reported, attributed to the presence of various lattice defects.26 Under excitation of 405 nm, compound 2 displays four strong characteristic emission peaks in the visible region for the SmIII ion, which are located around 561 nm (4G5/2 → 6H5/2), 598 nm (4G5/2 →

H7/2), and 646 and 704 nm (4G5/2 → 6H9/2). Upon excitation at 396 nm, there are six characteristic emission peaks for the EuIII ion in compound 3 in the visible region. The emission bands are attributed to 5D0 → 7FJ (J = 0−4) of the EuIII ion around 580, 593, 617, 686, and 694 nm, respectively, for compound 3. The symmetry-forbidden transition of 5D0 → 7F0 (580 nm) suggests that the EuIII ion possesses a noncentrosymmetric coordination environment. Compared with the 5D0 → 7F1 transition (magnetic dipole), the intensity of the 5 D0 → 7F2 transition (electric dipole) is much stronger, meaning asymmetric coordination geometries of the EuIII ions,26 which has been confirmed through single-crystal X-ray data. Under excitation of 338 nm, the luminescent curve diaplays a broad band at 450 nm for compound 4, which may also be assigned to the presence of various lattice defects as the reported borates. The metal-centered (MC) electronic levels are well above the ligand-centered electronic levels of organic ligands, and typically the Gd3+ ions are known to be located around 31000 cm−1. So, energy transfer from ligand to metal and the consequent MC luminescence cannot be observed for compound 4. Using 353 nm excitation light, the emission intensity is the weakest for compound 5 and four characteristic emission bands are observed: a strong emission band is at 525 nm and two are weak at 612 and 700 nm, corresponding to 4 F9/2 → 6F15/2, 4F9/2 → 6H13/2, and 4F9/2 → 6H11/2, respectively, and the band at 430 nm can be associated with the synergistic effect of lattice defects and 4F9/2 → 6F17/2 of Dy3+ ions. For compounds 2 and 3, there are no luminescent peaks around 400 nm due to the self-absorption of Ln ions. In comparison with the fluorescent spectra of other compounds (2−5), the transition intensity decreases in the following order: Eu3+ > 6

G

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Figure 5. Electronic density of states curves (a) and calculated band structure (b) for compound 1.

The distances between the nearest Ln3+···Ln3+ ions are 5.8274, 5.8177, 5.7935, and 5.7778 Å, respectively, for the Sm, Eu, Gd, and Dy compounds; hence, it is expected that the magnetic exchange interactions in these compounds are rather weak. The different magnetic behaviors of these compounds could be due to the different electronic configurations for the LnIII ions. More detailed information about these magnetic interactions were not performed because of the lack of suitable models available and their complicated structures. Theoretical Studies. To further explore the electronic structure for compound 1, theoretical calculations were performed using DFT methods. The electronic band structure of compound 1 is presented along high-symmetry k points in Figure 5. The state energies (electronvolts) of the highest valence band (HVB) and lowest conduction band (LCB) are presented in Table S1, suggesting that the maximum of HVB is localized between the A and G points and the minimum of LCB is localized at the V point. Compound 1 is an indirectband-gap material with a calculated band gap of 4.85 eV, which is larger than the experimental one of 4.07 eV because of the limitation of the DFT methods.31 The valence band located from −21.0 to −16 eV contains contributions mostly from O 2s, with some amount of B 2s2p, C 2s2p, and H 1s states from the total and partial densities of states in Figure 5. The second region, around −13 eV, is mainly contributed by Ga 3d states. The next region around −12 eV mostly originates from the C 2s2p and H 1s states. The vicinity of the Fermi level extending from −10.5 to 0 eV and from 4.5 to 11.1 eV in the valence and conduction bands, respectively, originates from the O 2p, B 2s2p, Ga 4s4p, C 2s2p, and H 1s states which are overlapped fully among them. More information about quantitative bond analysis has been supplied by population analyses. For Ga−O, H−O, and B−O bonds, the calculated bond orders are 0.28−0.34, 0.58−0.80, and 0.58−0.89 e, respectively, which mean that the Ga−O bonds are much weaker than the B−O bonds in the compound. Furthermore, for the BO3 units, the bond orders range from 0.68 to 0.89 e, which are significantly larger than those for the BO4 units (0.58−0.67 e). For the Y−O bonds, the bond orders range from −0.10 to +0.14 e, which are very small, meaning that they are mainly ionic in nature.

Sm3+ > Gd3+ > Dy3+. This suggests that energy transfer from the organic anions to the EuIII and SmIII ions is more effective than that to the GdIII and DyIII ions. The luminescent lifetimes for compounds 2 (λex = 397 nm; λem = 598 nm), 3 (λex = 396 nm; λem = 647 nm), and 5 (λex = 397 nm; λem = 524 nm) are 3.6, 0.86, and 3.05 ns, respectively, and the lifetime for compound 4 is too short to be measured (Figure S7).26,27 Magnetic Properties. The magnetic properties of Ln2Ga[B3O6(OH)]2[B7O9(OH)2](CH3CO2)2 [Ln = Y (1), Sm (2), Eu (3), Gd (4), Dy (5)] have been measured at temperatures ranging from 2 to 300 K at a magnetic field of 1000 Oe. Plots of the molar magnetic susceptibility (χ) and corresponding reciprocal susceptibility (χ−1) versus temperature (T) are shown in Figure 4. For compounds 2 and 3, their magnetic susceptibilities seriously deviated from the Curie−Weiss law in most of the temperature regions in the plot of χ−1 versus T. At 300 K, the effective magnetic moments (μeff) were evaluated as 2.36 and 4.83 μB for compounds 2 and 3, which are close to the expected values for the two isolated Sm3+ and Eu3+ ions, respectively. Upon cooling, the values of μeff decrease continuously and reach 0.89 and 0.51 μB at 2 K for compounds 2 and 3, respectively, which indicates that there exist antiferromagnetic interactions between magnetic centers in the two compounds.28 Furthermore, for compound 3, the magnetic susceptibility (χ) increases smoothly and then tends to a plateau as T is lowered. However, as T is further lowered, χ increases again at very low temperature, which can be assigned to the existence of a few parts per million of a rare-earth metal ion with a paramagnetic ground state in the compound.29a At the lowest temperature, the value of χT approaches zero (at 2 K, χT = 0.032), which indicates a J = 0 ground state of the Eu3+ ions (7F0).29b For compounds 4 and 5, they obey the Curie− Weiss law at temperatures ranging from 50 to 300 K. At 300 K, the effective magnetic moments (μeff) were evaluated as 11.05 and 14.74 μB for compounds 4 and 5, which are close to the expected values for the two isolated Gd3+ and Dy3+ ions, respectively. Upon cooling, the values of μeff remain almost unchanged for compound 4 and decrease slightly for compound 5, which indicate that both compounds are essentially paramagnetic.26,28 Filling of the magnetic data in the range of 50−300 K gave Curie constants (C) of 16.97 and 27.49 emu mol−1 K and Weiss temperatures (θ) of −0.99 and −3.55 K, respectively, for compounds 4 and 5, which indicate that there are very weak antiferromagnetic coupling interactions between neighboring Ln ions.29c,d,30

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CONCLUSIONS In summary, the first series of mixed-anion lanthanide galloborates, namely, Ln 2 Ga[B 3 O 6 (OH)] 2 [B 7 O 9 (OH) 2 ](CH3CO2)2 [Ln = Y (1), Sm (2), Eu (3), Gd (4), Dy (5)], H

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(5) (a) Wang, J. H.; Wei, Q.; Cheng, J. W.; He, H.; Yang, B. Y.; Yang, G. Y. Chem. Commun. 2015, 51, 5066−5068. (b) Yang, H.; Hu, C. L.; Song, J. L.; Mao, J. G. RSC Adv. 2014, 4, 45258−45265. (c) Bai, C. Y.; Han, S. J.; Pan, S. L.; Zhang, B. B.; Yang, Y.; Li, L.; Yang, Z. H. RSC Adv. 2015, 5, 12416−12422. (6) (a) Lin, Z.; Yang, G. Eur. J. Inorg. Chem. 2011, 2011, 3857−3867. (b) Touboul, M.; Penin, N.; Nowogrocki, G. Solid State Sci. 2003, 5, 1327−1342. (c) Huang, Y.; Wu, L.; Wu, X.; Li, L.; Chen, L.; Zhang, Y. J. Am. Chem. Soc. 2010, 132, 12788−12789. (d) Wang, L.; Pan, S.; Chang, L.; Hu, J.; Yu, H. Inorg. Chem. 2012, 51, 1852−1858. (e) Ju, J.; Yang, T.; Li, G. B.; Liao, F. H.; Wang, Y. X.; You, L. P.; Lin, J. H. Chem. - Eur. J. 2004, 10, 3901−3906. (7) (a) McMillen, C. D.; Stritzinger, J. T.; Kolis, J. W. Inorg. Chem. 2012, 51, 3953−3955. (b) Schubert, D. M.; Visi, M. Z.; Khan, S.; Knobler, C. B. Inorg. Chem. 2008, 47, 4740−4745. (c) Wu, H.; Pan, S.; Poeppelmeier, K. R.; Li, H.; Jia, D.; Chen, Z.; Fan, X.; Yang, Y.; Rondinelli, J. M.; Luo, H. J. Am. Chem. Soc. 2011, 133, 7786−7790. (d) Yang, H.; Hu, C. L.; Song, J. L.; Mao, J. G. RSC Adv. 2014, 4, 45258−45265. (8) (a) Liu, Z.; Li, L.; Zhang, W. Inorg. Chem. 2006, 45, 1430−1432. (b) Belokoneva, E. L.; Dimitrova, O. V. Inorg. Chem. 2013, 52, 3724− 3727. (c) Tian, H.; Wang, W.; Gao, Y.; Deng, T.; Wang, J.; Feng, Y.; Cheng, J. Inorg. Chem. 2013, 52, 6242−6244. (d) Yang, Y.; Pan, S.; Han, J.; Hou, X.; Zhou, Z.; Zhao, W.; Chen, Z.; Zhang, M. Cryst. Growth Des. 2011, 11, 3912−3916. (9) (a) Heyward, C.; McMillen, C.; Kolis, J. Inorg. Chem. 2012, 51, 3956−3962. (b) Beckett, M. A.; Horton, P. N.; Coles, S. J.; Martin, D. W. Inorg. Chem. 2011, 50, 12215−12218. (c) Tian, H.; Wang, W.; Zhang, X.; Feng, Y.; Cheng, J. Dalton Trans. 2013, 42, 894−897. (10) (a) Hao, Y. C.; Hu, C. L.; Xu, X.; Kong, F.; Mao, J. G. Inorg. Chem. 2013, 52, 13644−13650. (b) Zhang, J. H.; Kong, F.; Mao, J. G. Inorg. Chem. 2011, 50, 3037−3043. (c) Xiong, D. B.; Zhao, J. T.; Chen, H. H.; Yang, X. X. Chem. - Eur. J. 2007, 13, 9862−9865. (11) (a) Pan, S. L.; Wu, Y. C.; Fu, P. Z.; Zhang, G. C.; Li, Z. H.; Du, C. X.; Chen, C. T. Chem. Mater. 2003, 15, 2218−2221. (b) Wang, Y.; Pan, S. L.; Zhang, M.; Han, S. J.; Su, X.; Dong, L. Y. CrystEngComm 2013, 15, 4956−4962. (c) Gou, W. B.; He, Z. Z.; Yang, M.; Zhang, W. L.; Cheng, W. D. Inorg. Chem. 2013, 52, 2492−2496. (12) (a) Daub, M.; Hillebrecht, H. Chem. - Eur. J. 2015, 21, 298−304. (b) Daub, M.; Höppe, H.; Hillebrecht, H. Z. Anorg. Allg. Chem. 2014, 640, 2914−2921. (c) Daub, M.; Kazmierczak, K.; Gross, P.; Höppe, H.; Hillebrecht, H. Inorg. Chem. 2013, 52, 6011−6020. (13) (a) Liu, Z. H.; Yang, P.; Li, P. Inorg. Chem. 2007, 46, 2965− 2967. (b) Hu, T.; Qin, L.; Kong, F.; Zhou, Y.; Mao, J. G. Inorg. Chem. 2009, 48, 2193−2199. (c) Cheng, L.; Wei, Q.; Wu, H. Q.; Zhou, L. J.; Yang, G. Y. Chem. - Eur. J. 2013, 19, 17662−17667. (d) Yang, H.; Hu, C. L.; Song, J. L.; Mao, J. G. RSC Adv. 2014, 4, 45258−45265. (14) (a) Smith, R. W.; Kennard, M. A.; Dudik, M. Mater. Res. Bull. 1997, 32, 649−656. (b) Li, R. K.; Yu, Y. Inorg. Chem. 2006, 45, 6840− 6843. (c) Deng, T. T.; Gao, Y. E.; Zhang, L. X.; Gu, X. Y.; Tian, H. R.; Liu, Y.; Feng, Y. L.; Cheng, J. W. CrystEngComm 2014, 16, 5689. (d) Cheng, L.; Wei, Q.; Wu, H. Q.; Zhou, L. J.; Yang, G. Y. Chem. Eur. J. 2013, 19, 17662−17667. (e) Vitzthum, D.; Schauperl, M.; Strabler, C. M.; Brüggeller, P.; Liedl, K. R.; Griesser, U. J.; Huppertz, H. Inorg. Chem. 2016, 55, 676−681. (15) Cheng, L.; Yang, G. Y. J. Solid State Chem. 2013, 198, 87−92. (16) (a) Gómez-Aguirre, L. C.; Pato-Doldán, B.; Stroppa, A.; YáñezVilar, S.; Bayarjargal, L.; Winkler, B.; Castro-García, S.; Mira, J.; Sánchez-Andújar, M.; Señarís-Rodríguez, M. A. Inorg. Chem. 2015, 54, 2109−2116. (b) Fan, X.; Pan, S.; Guo, J.; Hou, X.; Han, J.; Zhang, F.; Li, F.; Poeppelmeier, K. R. J. Mater. Chem. A 2013, 1, 10389−10394. (17) (a) Zhu, W. H.; Wang, Z. M.; Gao, S. Dalton Trans. 2006, 765− 768. (b) Cui, H. B.; Wang, Z. M.; Takahashi, K.; Okano, Y.; Kobayashi, K.; Kobayashi, A. J. Am. Chem. Soc. 2006, 128, 15074− 15075. (18) Yang, H.; Hu, C. L.; Xu, X.; Mao, J. G. Inorg. Chem. 2015, 54, 7516−7523. (19) Wendlandt, W. M.; Hecht, H. G. Reflectance Spectroscopy; Interscience: New York, 1966.

has been obtained through hydrothermal reactions. They crystallize in monoclinic space group C2/c (No. 15). They are isomorphic and possess [B7O13(OH)2] borate layers, which are further bridged with [B3O7] groups to give a 3D borate framework displaying two types of rhombus-like B14O14 14-MR channels along the b axis. The Ga3+ ions are octahedrally coordinated and located at one kind of B14O14 14-MR channel, forming small tunnels of B7Ga 8-MRs, which are filled by the LnIII ions. The Ln ions and GaIII cations are further held together by bridging acetate anions. It is worth noting that in these compounds there are two different types of borate clusters and two types of anions that are uncommon in the borates reported. Luminescent studies show the characteristic emission bands of lanthanides for compounds 2−5, and the luminescent lifetimes for compounds 2, 3, and 5 are 3.6, 0.86, and 3.05 ns. Magnetic measurements reveal that there are antiferromagnetic interactions between magnetic centers for compounds 2−5.

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ASSOCIATED CONTENT

* Supporting Information S

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.6b00584. State energies (electronvolts) of the LCB and HVB of compound 1, views of {B3} and {B7}, coordination geometries of Y, coordination modes of the acetate anions and Ga atoms in 1, size of the B14O14 14-MR in the ab plane, view of the linkages of borate clusters and Ga atoms in GaB5O8(OH)2(en)2·H2O, LiGa(OH) (BO3)(H2O), Rb2Ga(B5O10)(H2O)4, and Ba3Ga2[B3O6(OH)]2[B4O7(OH)2], simulated and experimental powder XRD patterns, IR and UV spectra, optical diffuse reflectance, TGA and DSC data for all compounds, and decay curves (PDF) X-ray crystallographic data in CIF format (CIF)

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Fax: (+86)591-83714946. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This investigation was supported by the National Natural Science Foundation of China (Grants 21231006, 21373222, and 21401194).

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REFERENCES

(1) (a) Ok, K. M.; Chi, E. O.; Halasyamani, P. S. Chem. Soc. Rev. 2006, 35, 710−717. (b) Chen, C. T.; Liu, G. Z. Annu. Rev. Mater. Sci. 1986, 16, 203−243. (c) Ok, K. M.; Chi, E. O.; Halasyamani, P. S. Chem. Soc. Rev. 2006, 35, 710−717. (2) (a) Hagerman, M. E.; Poeppelmeier, K. R. Chem. Mater. 1995, 7, 602−621. (b) Eaton, D. F. Science 1991, 253, 281−287. (3) (a) Ye, N.; Stone-Sundberg, J. L.; Hruschka, M. A.; Aka, G.; Kong, W.; Keszler, D. A. Chem. Mater. 2005, 17, 2687−2692. (b) Zhao, S. G.; Gong, P. F.; Bai, L.; Xu, X.; Zhang, S. G.; Sun, Z. H.; Lin, Z. S.; Hong, M. C.; Chen, C. T.; Luo, J. H. Nat. Commun. 2014, 5, 4019. (4) (a) Sasaki, T.; Mori, Y.; Yoshimura, M.; Yap, Y. K.; Kamimura, T. Mater. Sci. Eng., R 2000, 30, 1. (b) Wang, S. C.; Ye, N.; Li, W.; Zhao, D. J. Am. Chem. Soc. 2010, 132, 8779−8786. I

DOI: 10.1021/acs.inorgchem.6b00584 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry (20) (a) CrystalClear, version 1.3.5; Rigaku Corp.: The Woodlands, TX, 1999. (b) Sheldrick, G. M. SHELXTL, Crystallographic Software Package, version 5.1; Bruker-AXS: Madison, WI, 1998. (c) Spek, A. L. PLATON; Utrecht University: Utrecht, The Netherlands, 2001. (21) (a) Segall, M. D.; Lindan, P. J. D.; Probert, M. J.; Pickard, C. J.; Hasnip, P. J.; Clark, S. J.; Payne, M. C. J. Phys.: Condens. Matter 2002, 14, 2717−2744. (b) Milman, V.; Winkler, B.; White, J. A.; Pickard, C. J.; Payne, M. C.; Akhmatskaya, E. V.; Nobes, R. H. Int. J. Quantum Chem. 2000, 77, 895−910. (22) Perdew, J. P.; Burke, K.; Ernzerhof, M. Phys. Rev. Lett. 1996, 77, 3865−3868. (23) (a) Lin, J. S.; Qteish, A.; Payne, M. C.; Heine, V. Phys. Rev. B: Condens. Matter Mater. Phys. 1993, 47, 4174−4180. (b) Bassani, F.; Parravicini, G. P. Electronic States and Optical Transitions in Solids; Pergamon Press Ltd.: Oxford, U.K., 1975. (24) (a) Hu, T.; Qin, L.; Kong, F.; Zhou, Y.; Mao, J. G. Inorg. Chem. 2009, 48, 2193−2199. (b) Cheng, L.; Wei, Q.; Wu, H. Q.; Zhou, L. J.; Yang, G. Y. Chem. - Eur. J. 2013, 19, 17662−17667. (25) (a) Brese, N. E.; O'Keeffe, M. Acta Crystallogr., Sect. B: Struct. Sci. 1991, 47, 192−197. (b) Altermatt, D.; Brown, I. D. Acta Crystallogr., Sect. B: Struct. Sci. 1985, 41, 240−244. (26) (a) Deng, T. Y.; Gao, Y. E.; Zhang, L. X.; Gu, X. Y.; Tian, H. R.; Liu, Y.; Feng, Y. L.; Cheng, J. W. CrystEngComm 2014, 16, 5689− 5694. (b) Rong, C.; Yu, Z. W.; Wang, Q.; Zheng, S. T.; Pan, C. Y.; Deng, F.; Yang, G. Y. Inorg. Chem. 2009, 48, 3650−3659. (c) Kirby, A. F.; Foster, D.; Richardson, F. S. Chem. Phys. Lett. 1983, 95, 507−512. (27) (a) Zhang, J. H.; Li, P. X.; Mao, J. G. Dalton Trans. 2010, 39, 5301−5305. (b) Yi, F. Y.; Lin, Q. P.; Zhou, T. H.; Mao, J. G. Cryst. Growth Des. 2010, 10, 1788−1797. (c) Latshaw, A. M.; Hughey, K. D.; Smith, M. D.; Yeon, J.; zur Loye, H. C. Inorg. Chem. 2015, 54, 876− 884. (d) Sun, L. N.; Qiu, Y. N.; Liu, T.; Zhang, J. Z.; Dang, S.; Feng, J.; Wang, Z. J.; Zhang, H. J.; Shi, L. Y. ACS Appl. Mater. Interfaces 2013, 5, 9585−9593. (e) Mohitkar, S. A.; Kalpana, G.; Vidyasagar, K. J. Solid State Chem. 2011, 184, 735−740. (f) Chen, M.; Xie, L.; Li, F.; Zhou, S.; Wu, L. ACS Appl. Mater. Interfaces 2010, 2, 2733−2737. (g) Cong, R. H.; Yang, T.; Wang, Z. M.; Sun, J. L.; Liao, F. H.; Wang, Y. X.; Lin, J. X. Inorg. Chem. 2011, 50, 1767−1774. (28) West, J. P.; Hwu, S. J.; Queen, W. L. Inorg. Chem. 2009, 48, 8439−8444. (29) (a) Andruh, M.; Bakalbassis, E.; Kahn, O.; Trombe, J. C.; Porcher, P. Inorg. Chem. 1993, 32, 1616−1622. (b) Zhang, S. Y.; Mao, J. G. Inorg. Chem. 2011, 50, 4934−4943. (c) Costes, J. P.; Nicodeme, F. Chem. - Eur. J. 2002, 8, 3442−3447. (d) Qian, X. Y.; Zhang, J. H.; Zhou, T. H.; Mao, J. G. Dalton Trans. 2012, 41, 1229−1236. (30) (a) Arauzo, A.; Lazarescu, A.; Shova, S.; Bartolomé, E.; Cases, R.; Luzón, J.; Bartolomé, J.; Turta, C. Dalton Trans. 2014, 43, 12342− 12356. (b) Lin, J.; Diefenbach, K.; Fu, J. C.; Cross, J. N.; Clark, R. J.; Albrecht-Schmitt, T. E. Inorg. Chem. 2014, 53, 9058−9064. (31) (a) Zhang, F. Y.; Jing, Q.; Zhang, F. F.; Pan, S. L.; Yang, Z. H.; Han, J.; Zhang, M.; Han, S. J. J. Mater. Chem. C 2014, 2, 667−674. (b) Yang, H.; Hu, C. L.; Song, J. L.; Mao, J. G. RSC Adv. 2014, 4, 45258−45265. (c) Hu, T.; Hu, C. L.; Kong, F.; Mao, J. G.; Mak, T. W. Inorg. Chem. 2012, 51, 8810−8817. (d) Yan, D.; Hu, C. L.; Mao, J. G. CrystEngComm 2016, 18, 1655−1664.

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DOI: 10.1021/acs.inorgchem.6b00584 Inorg. Chem. XXXX, XXX, XXX−XXX