A Member of Fluorooxoborates: Li2Na0.9K0.1B5O8F2 with the

Article Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX

pubs.acs.org/IC

A Member of Fluorooxoborates: Li2Na0.9K0.1B5O8F2 with the Fundamental Building Block B5O10F2 and a Short Cutoff Edge Shujuan Han, Ying Wang, Bingbing Zhang, Zhihua Yang, and Shilie Pan* CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS; Xinjiang Key Laboratory of Electronic Information Materials and Devices, 40-1 South Beijing Road, Urumqi 830011, China S Supporting Information *

ABSTRACT: A new member of fluorooxoborates, Li2Na0.9K0.1B5O8F2, was obtained in the sealed system, and single-crystal X-ray diffraction was used to determine its structure. It contains a three-dimensional framework stacking of [B5O8F2]3− layers extending into the ac plane. Detailed structural comparisons among all of the fluorine-containing alkali-metal borates suggest that the [B5O8F2]3− layer composed of the new fundamental building blocks B5O10F2 represents a new structure type of fluorooxoborate. The IR spectrum verifies its structural validity. The deep-ultraviolet spectral measurement shows that it has no obvious absorption in the range of 180−300 nm, and its cutoff edge is under 180 nm. In addition, theoretical calculations were done to help us understand its electronic structure and optical properties.

■

fluorooxoborates, K3B3O3F6,46 Li2B6O9F2,51 Na2B6O9F255 and CsB4O6F,56 among which Li2B6O9F2 and CsB4O6F are identified as DUV materials with suitable nonlinear-optical efficiency, short cutoff edge, and suitable birefringence. This work will report a new compound, Li2Na0.9K0.1B5O8F2 (CCDC 1579283), which is the first fluorooxoborate containing more than one kind of alkali metal. In addition, its fundamental building block (FBB) and DUV cutoff edge also attract our attention. In this paper, its synthesis and optical characterization are discussed. Also, all of the fluorinecontaining alkali-metal borates are summarized; the detailed structural comparisons among them have also been discussed. Meanwhile, calculations of its electronic structure are also presented.

INTRODUCTION Nowadays, exploring new materials is needed to satisfy the development of science and technology.1−8 Recent research of new crystals is directed toward introducing special units into the structure, for example, π-orbital systems ([BO3]3−, [CO3]2−, [NO3]−, etc.),3,9−21 cations with lone-pair electrons (I5+, Bi3+, Se4+, Pb2+, etc.),22−30 d0 transition metals with octahedral coordination (Ti4+, Mo6+, Ta5+, etc.),31−36 and so on. After numerous attempts, many excellent crystals, especially borates, that may be used in various fields have been obtained.37−45 Moreover, among all of the borates, fluorine-containing alkali-metal borates have become the theme of important research because of their excellent properties and abundant structures, especially the shorter ultraviolet (UV) cutoff edge, making them suitable for applications in the deep-ultraviolet (DUV) regions. To our best knowledge, such compounds are known as borate fluorides because the fluorine atom is exclusively coordinated to the alkali-metal atom, for example, Li6RbB2O6F.46 In another class of the fluorine-containing borates, the fluorine atom is directly connected to the boron atom; that is, fluorine is substituted for the oxygen atom. This kind of compound is named a fluorooxoborate, such as Li2B3O4F3, Li2B6O9F2, LiB6O9F, etc.47−54 In general, the oxygen atoms of the BO4 tetrahedron can be substituted by the fluorine atom, which will reduce the crystal structural symmetry and further affect the crystal properties. On the basis of the above idea, we have paid more attention to the alkali metal−fluorine−boron system with the intention to explore new fluorooxoborates that can potentially be used as DUV optical materials. Our efforts have produced several new © XXXX American Chemical Society

■

EXPERIMENTAL SECTION

Synthesis. The title crystal was obtained from a high-temperature solution in the sealed system. First, the mixture of LiF, NaF, KF, and B2O3 with a molar ratio of 3:1:1:5 was put into a platinum crucible, heated for 5 h at 320 °C, then cooled to 30 °C, and ground. After that, we loaded the preheated mixture into a tidy quartz tube. After being dried at a high temperature, the tube was flame-sealed under 10−3 Pa, and then it was heated at 450 °C for 12 h. Subsequently, the temperature was decreased to 300 °C at a rate of 1 °C/h and last lowered to 30 °C at a rate of 5 °C/h. Some colorless crystals were separated from the tube for structural characterization. The polycrystalline sample of Li2Na0.9K0.1B5O8F2 was prepared via a solid-state reaction in the sealed system. The mixture (LiF, NaBF4, KBF4, and H3BO3 with a molar ratio of 2:0.9:0.1:4) was preheated for Received: November 7, 2017

A

DOI: 10.1021/acs.inorgchem.7b02838 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry 3 h at 280 °C and then heated at 380 °C for 10 h. After sintering at 380 °C, the sample was ground again. Then the preheated mixture was put into a tidy quartz tube, which was flame-sealed under 10−3 Pa. The tube was heated at 280 °C for 65 h. Powder X-ray diffraction (XRD) was used to confirm the purity of the polycrystalline sample. A Bruker D2 PHASER diffractometer with Cu Kα radiation (λ = 1.5418 Å) was used to collect the data, and the diffraction patterns were collected in the range of 10−70° (2θ). The fixed counting time and scan step width are 1 s/step and 0.02°, respectively. The diffraction pattern agrees well with the theoretical one except for two little impurity peaks, as shown in Figure S1. Structural Determination. At 296(2) K, collection of the singlecrystal XRD data was performed by a Bruker SMART APEX II 4K CCD diffractometer using Mo Kα radiation (λ = 0.71073 Å). A SAINT program was used to integrate the data.57 The direct methods and SHELXTL system were used to solve and refine the crystal structure, respectively.58 The positions of all of the atoms were refined using full-matrix least-squares techniques. Table 1 summarizes the

Shimadzu. The measurement range is from 500 to 4000 cm−1. The dried KBr was used to mix the sample. For determination of the exact absorption edge, the DUV diffusereflectance spectrum was measured in the flowing N2 atmosphere using a SolidSpec-3700DUV spectrophotometer from Shimadzu. The measurement range is from 180 to 300 nm. Also, the reflectance spectrum was transformed into absorbance with the Kubelka−Munk function.59 Theoretical Calculations. The electronic structures were calculated using the density functional theory (DFT) method embedded in the CASTEP package.60 The calculations were performed with the norm-conserving pseudopotentials.61−63 The exchange-correlation functional was the Perdew−Burke−Emzerhof (PBE) functional within the generalized gradient approximation (GGA).64 The plane-wave energy cutoff was set at 850.0 eV. Selfconsistent-field calculations were performed with a convergence criterion of 1 × 10−6 eV/atom on the total energy. The k-point separation for each material was set as 0.07 Å−1 in the Brillouin zone.

Table 1. Crystal Data and Structure Refinement of Li2Na0.9K0.1B5O8F2

RESULTS AND DISCUSSION Structural Description. Li2Na0.9K0.1B5O8F2 crystallizes in the centrosymmetric orthorhombic symmetry (space group Pbcn). Its structure shows a three-dimensional (3D) framework constructed by LiO5, Na/KO4F4, BO3, BO4, and BO3F groups. A notable feature can be found in its structure: it contains [B5O8F2]3− layers extending into the ac plane (Figure 1b) composed of a new FBB, B5O10F2 (Figure 1a). We define the [B5O8F2]3− layer as the “A layer”, which can be rotated 180° around the a axis relative to the A′ layer (Figure 1c). The A and A′ layers are alternately arranged along the b axis (Figure 1c), forming the anionic framework of the structure. All of the layers are bridged by the cations, which are also used to balance the charges. There are one unique lithium atom, one common site of sodium/potassium, three unique boron atoms, four unique oxygen atoms, and one unique fluorine atom in its asymmetric unit (Table 2). In the structure, the boron atoms own three coordination environments, the B1O4, B2O3, and B3O3F polyhedra (Figure 1a), and the B−O bond lengths are 1.435−1.499 Å for B1−O, 1.351−1.375 Å for B2−O, and 1.424−1.478 Å for B3−O. The B−F bond length in B3O3F is 1.437(2) Å, which can be found in Table S1. The unique lithium atom is coordinated to five oxygen atoms, forming the LiO5 polyhedron. Two LiO5 polyhedra are linked together via edge-sharing through two oxygen atoms, forming the Li2O8 group, which is isolated in the structure (Figure S2). Na+ and K+ have similar ionic radii; therefore, it is feasible that the sodium and potassium atoms are located in the same position. The Na/KO4F4 polyhedra are connected to build up the one-dimensional (1D) chains

empirical formula fw cryst syst, space group a (Å) b (Å) c (Å) volume (Å3) Z, calcd density F(000) cryst size (mm3) θ range for data collection limiting indices reflns collected/unique completeness to θ = 27.683° no. of data/restraints/param GOF on Fo2 final R indices [Fo2 > 2σ(Fo2)]a R indices (all data)a largest diff peak and hole (e/ Å3)

■

Li2Na0.9K0.1B5O8F2 258.53 orthorhombic, Pbcn 8.797(7) 9.293(7) 8.224(7) 672.4(9) 4, 2.554 g/cm3 499 0.205 × 0.191 × 0.069 3.189−27.683 −11 ≤ h ≤ 11, −5 ≤ k ≤ 12, −10 ≤ l ≤ 10 3715/793 [R(int) = 0.0434] 100.00% 793/0/84 1.095 R1 = 0.0287, wR2 = 0.0663 R1 = 0.0352, wR2 = 0.0704 0.250 and −0.215

R1 = ∑||Fo| − |Fc||/∑|Fo| and wR2 = [∑w(Fo2 − Fc2)2/∑wFo4]1/2 for Fo2 > 2σ(Fo2).

a

crystal data and structural refinement. Table 2 shows the atomic coordinates and the equivalent isotropic displacement parameters. Table S1 lists the selected bond angles and lengths. Optical Characterization. The IR spectrum was recorded using an IRAffinity-1 Fourier transform infrared spectrometer from

Table 2. Atomic Coordinates (×104) and Equivalent Isotropic Displacement Parameters (Å2 × 103) for Li2Na0.9K0.1B5O8F2a atom

x

y

z

Ueq

occupancy

BVS

Li1 Na1/K1 B1 B2 B3 O1 O2 O3 O4 F1

4493(3) 10000 5000 7550(2) 7220(2) 5959(1) 8117(1) 9044(1) 6680(1) 8257(1)

1557(3) 183(1) −1229(3) 2579(2) −1031(2) −367(1) −1941(1) 2797(1) 1817(1) 64(1)

746(3) 2500 2500 1780(2) 4307(2) 3522(1) 3190(1) 1470(1) 735(1) 4844(1)

18(1) 25(1) 11(1) 12(1) 11(1) 11(1) 14(1) 14(1) 13(1) 19(1)

1 0.9/0.1 1 1 1 1 1 1 1 1

1.10 0.85 3.10 3.09 3.11 2.06 2.06 2.10 2.16 0.89

a

Ueq is defined as one third of the trace of the orthogonalized Uij tensor. B

DOI: 10.1021/acs.inorgchem.7b02838 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry

Figure 2. IR spectrum of Li2Na0.9K0.1B5O8F2.

symmetric extension leads to the absorption peak near 855 cm−1. The peaks observed near 1035 and 764 cm−1 are related to the B−F asymmetric and symmetric extending vibrations of tetrahedral BO3F, respectively. The peaks around 723, 678, and 637 cm−1 can originate from the out-of-plane bending mode of BO3. The peaks close to 597 and 530 cm−1 characterize the bending modes of BO4 and BO3. The IR measurement verifies the presence of the BO3, BO4 and BO3F tetrahedra and corresponds with the structural analysis. In addition, the energy-dispersive X-ray (EDX) spectrum also confirms the existence of fluorine (Figure S7). Figure 3 shows the DUV diffuse-reflectance spectrum of Li2Na0.9K0.1B5O8F2. It is apparent that the compound has no

Figure 1. (a) B5O10F2 group. (b) [B5O8F2]3− layer extending into the ac plane. (c) Crystal structure of Li2Na0.9K0.1B5O8F2.

extending along the c axis (Figure S3). The situation in which K+ and Na+ are disordered can also be found in other borates.65,66 From Table 2, we can see that the bond-valencesum (BVS) calculations65 of the atoms are reasonable. Structural Comparisons among All of the FluorineContaining Alkali-Metal Borates. To our best knowledge, six alkali-metal fluorooxoborates have been obtained except for the title one. Also, crystal structural comparisons including the space group, anionic framework, etc., between the title crystal and the six reported ones are summarized in Table S2. It can be seen that, with the cation/boron ratio increasing, the dimensions of the anionic framework almost decrease except for Li2B6O9F2. When the cation/boron value is less than or equal to 0.6, the anionic frameworks display various twodimensional-layer configurations in the structures of LiB6O9F, Na2B6O9F2, CsB4O6F, and Li2Na0.9K0.1B5O8F2, which can be seen in Figures 1 and S4. The anionic framework shows a 1D [B3O4F3]2− chain in the structure of Li2B3O4F3 (Figure S5a), whose cation/boron value is 0.67. Also, while the cation/boron ratio is 1, isolated [B3O3F6]3− groups can be found in the structures of Na3B3O3F6 and K3B3O3F6 (Figure S5b,c). However, Li2B6O9F2 exhibits a 3D B−O−F network (Figure S6a). In addition, it can be found that only one alkali-metal borate fluoride, Li6RbB2O6F, has been reported, recently. Compared with the above compounds, we can see that Li6RbB2O6F contains more cations; hence, only isolated BO3 units can be seen in its structure (Figure S6b). Optical Analysis. Figure 2 shows the IR spectrum of Li2Na0.9K0.1B5O8F2, which is used to specify coordination of the boron atoms. According to refs 46, 49, 50, 53, 67, and 68, the following absorption peaks in the IR spectrum were assigned. The absorption peaks observed at 1382 and 1320 cm−1 are caused by the asymmetric extending vibration of BO3. The asymmetric extension of B−O in the BO4 results in the absorption peaks around 1193 and 909 cm−1, and its

Figure 3. DUV diffuse-reflectance spectrum of Li2Na0.9K0.1B5O8F2.

obvious absorption ranging from 180 to 300 nm, so its cutoff edge is below 180 nm, which indicates that Li2Na0.9K0.1B5O8F2 may be used as the DUV crystal. The high transparency of Li2Na0.9K0.1B5O8F2 can be explained as follows: First, because of the empty f and d orbitals of the alkaline-metal cations, they are beneficial to the cutoff edge shift to the UV region. In addition, because of the large electronegativity of fluorine, the introduction of fluorine in the compound leads to a large band gap, making it suitable for DUV light transmission. Theoretical Analysis. Using the method mentioned above, we obtained the electronic structure and optical properties of Li2Na0.9K0.1B5O8F2. Li2Na0.9K0.1B5O8F2 owns a direct band gap of 5.81 eV (Figure 4), which is smaller than the experimental value. Noting that, because of the limitation of the DFT method, the band gap calculated by GGA−PBE is always underestimated.69 The partial density of states (PDOS) shows that the orbitals of the cations occur at a deep energy level and have no obvious proportion near the Fermi level. The largest orbital contributions on the top of the valence bands and the bottom of the conduction bands originate from the BOF network. There are obvious mixtures among boron, C

DOI: 10.1021/acs.inorgchem.7b02838 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry

Figure 4. Band structure (left) and PDOS (right) of Li2Na0.9K0.1B5O8F2.

oxygen, and fluorine atoms in the valence bands that indicate the covalent bond of B−O and B−F.

■

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected].

CONCLUSIONS After research of the alkali metal−fluorine−boron system, a new fluorooxoborate, Li2Na0.9K0.1B5O8F2, has been obtained. It is the first fluorooxoborate containing more than one kind of alkali metal. In its structure, the B5O10F2 units composed of two BO3, two BO3F, and one BO4 are linked together to build the [B5O8F2]3− layers, which are further bridged by the Li+ and Na+ ions to construct the 3D framework. The IR spectrum verifies the presence of the BO3, BO4, and BO3F groups. The DUV spectrum indicates that it can be used in the DUV optical region. In the future, we will explore other new compounds in this system.

■

■

ORCID

Ying Wang: 0000-0001-6642-543X Zhihua Yang: 0000-0001-8726-7952 Shilie Pan: 0000-0003-4521-4507 Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS

■

REFERENCES

This work was completed with the help of the National Natural Science Foundation of China (Grants U1703127 and 51425206), Xinjiang Program of Cultivation of Young Innovative Technical Talents (Grant QN2016BS0344), Urumqi Science and Technology Plan (Grant P151010004), National Key Research Project (Grant 2016YFB0402104), and Xinjiang Key Research and Development Program (Grant 2016B02021).

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.7b02838. Selected bond lengths and angles for Li2Na0.9K0.1B5O8F2, crystal structural comparisons among all of the fluorinecontaining alkali-metal borates, experimental and calculated XRD patterns of the compound, arrangement of cation coordination polyhedra, structures, and an EDX spectroscopy spectrum (PDF)

(1) Yu, H. W.; Zhang, W. G.; Young, J.; Rondinelli, J. M.; Halasyamani, P. S. Bidenticity-Enhanced Second Harmonic Generation from Pb Chelation in Pb3Mg3TeP2O14. J. Am. Chem. Soc. 2016, 138, 88−91. (2) Gao, W. L.; Wang, Y. X.; Li, G. B.; Liao, F. H.; You, L. P.; Lin, J. H. Synthesis and Structure of an Aluminum Borate Chloride Consisting of 12-Membered Borate Rings and Aluminate Clusters. Inorg. Chem. 2008, 47, 7080−7082. (3) Zou, G. H.; Huang, L.; Ye, N.; Lin, C. S.; Cheng, W. D.; Huang, H. CsPbCO3F: A Strong Second-Harmonic Generation Material Derived from Enhancement via p-π Interaction. J. Am. Chem. Soc. 2013, 135, 18560−18566. (4) Duan, M. H.; Xia, M. J.; Li, R. K. Ba5Zn4(BO3)6: A NonlinearOptical Material with Reinforced Interlayer Connections and Large Second-Harmonic-Generation Response. Inorg. Chem. 2017, 56, 11458−11461.

Accession Codes

CCDC 1579283 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by emailing [email protected], or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033. D

DOI: 10.1021/acs.inorgchem.7b02838 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry (5) Xia, M. J.; Jiang, X. X.; Lin, Z. S.; Li, R. K. “All-Three-in-One”: A New Bismuth−Tellurium−Borate Bi3TeBO9 Exhibiting Strong Second Harmonic Generation Response. J. Am. Chem. Soc. 2016, 138, 14190−14193. (6) Rondinelli, J. M.; Kioupakis, E. Predicting and Designing Optical Properties of Inorganic Materials. Annu. Rev. Mater. Res. 2015, 45, 491−518. (7) Bae, S. W.; Yoo, J.; Lee, S.; Choi, K. Y.; Ok, K. M. Synthesis and Characterization of Three New Layered Vanadium Tellurites, MVTe2O8 (M = Al, Ga, and Mn): Three-Dimensional (3-D) Antiferromagnetic Behavior of MnVTe2O8 with a Zigzag S = 2 Spin Chain. Inorg. Chem. 2016, 55, 1347−1353. (8) Shi, G. Q.; Wang, Y.; Zhang, F. F.; Zhang, B. B.; Yang, Z. H.; Hou, X. L.; Pan, S. L.; Poeppelmeier, K. R. Finding the Next DeepUltraviolet Nonlinear Optical Material: NH4B4O6F. J. Am. Chem. Soc. 2017, 139, 10645−10648. (9) Liang, F.; Kang, L.; Gong, P. F.; Lin, Z. S.; Wu, Y. C. Rational Design of Deep-Ultraviolet Nonlinear Optical Materials in Fluorooxoborates: Toward Optimal Planar Configuratio. Chem. Mater. 2017, 29, 7098−7102. (10) Li, L. Y.; Li, G. B.; Wang, Y. X.; Liao, F. H.; Lin, J. H. Bismuth Borates: One-Dimensional Borate Chains and Nonlinear Optical Properties. Chem. Mater. 2005, 17, 4174−4180. (11) Song, Y. X.; Luo, M.; Lin, C. S.; Ye, N. Structural Modulation of Nitrate Group with Cations to Affect SHG Responses in RE(OH)2NO3 (RE = La, Y, and Gd): New Polar Materials with Large NLO Effect after Adjusting pH Values of Reaction Systems. Chem. Mater. 2017, 29, 896−903. (12) Zhao, S. G.; Yang, Y.; Shen, Y. G.; Zhao, B. Q.; Li, L. N.; Ji, C. M.; Wu, Z. Y.; Yuan, D. Q.; Lin, Z. S.; Hong, M. C.; Luo, J. H. Cooperation of Three Chromophores Generates the Water-Resistant Nitrate Nonlinear Optical Material Bi3TeO6OH(NO3)2. Angew. Chem., Int. Ed. 2017, 129, 555−559. (13) Tran, T. T.; He, J. G.; Rondinelli, J. M.; Halasyamani, P. S. RbMgCO3F: A New Beryllium-Free Deep-Ultraviolet Nonlinear Optical Material. J. Am. Chem. Soc. 2015, 137, 10504−10507. (14) Yakubovich, O. V.; Yakovleva, E. V.; Golovanov, A. N.; Volkov, A. S.; Volkova, O. S.; Zvereva, E. A.; Dimitrova, O. V.; Vasiliev, A. N. The First Vanadate−Carbonate, K2Mn3(VO4)2(CO3): Crystal Structure and Physical Properties. Inorg. Chem. 2013, 52, 1538−1543. (15) Wang, S. C.; Ye, N. Na2CsBe6B5O15: An Alkaline Beryllium Borate as a Deep-UV Nonlinear Optical Crystal. J. Am. Chem. Soc. 2011, 133, 11458−11461. (16) Xu, K.; Loiseau, P.; Aka, G.; Lejay, J. A New Promising Nonlinear Optical Crystal for Ultraviolet Light Generation: Ca5(BO3)3F. Cryst. Growth Des. 2009, 9, 2235−2239. (17) Song, Y. X.; Luo, M.; Zhao, D.; Peng, G.; Lin, C. S.; Ye, N. Explorations of New UV Nonlinear Optical Materials in the Na2CO3−CaCO3 system. J. Mater. Chem. C 2017, 5, 8758−8764. (18) Huang, H. W.; Liu, L. J.; Jin, S. F.; Yao, W. J.; Zhang, Y. H.; Chen, C. T. Deep-Ultraviolet Nonlinear Optical Materials: Na2Be4B4O11 and LiNa5Be12B12O33. J. Am. Chem. Soc. 2013, 135, 18319−18322. (19) Wu, L.; Zhang, Y.; Kong, Y. F.; Sun, T. Q.; Xu, J. J.; Chen, X. L. Structure Determination of Novel Orthoborate NaMgBO3: A Promising Birefringent Crystal. Inorg. Chem. 2007, 46, 5207−5211. (20) Mutailipu, M.; Su, X.; Zhang, M.; Yang, Z. H.; Pan, S. L. Ban+2Znn(BO3)n(B2O5)Fn (n = 1, 2): New Members of the Zincoborate Fluoride Series with Two Kinds of Isolated B−O Units. Inorg. Chem. Front. 2017, 4, 281−288. (21) Kang, L.; Lin, Z. S.; Qin, J. G.; Chen, C. T. Two Novel Nonlinear Optical Carbonates in the Deep-Ultraviolet Region: KBeCO3F and RbAlCO3F2. Sci. Rep. 2013, 3, 1366−1370. (22) Kim, Y. H.; Tran, T. T.; Halasyamani, P. S.; Ok, K. M. Macroscopic Polarity Control with Alkali Metal Cation Size and Coordination Environment in a Series of Tin Iodates. Inorg. Chem. Front. 2015, 2, 361−368. (23) Luo, Z. Z.; Lin, C. S.; Cui, H. H.; Zhang, W. L.; Zhang, H.; Chen, H.; He, Z. Z.; Cheng, W. D. PbGa2MSe6 (M = Si, Ge): Two

Exceptional Infrared Nonlinear Optical Crystals. Chem. Mater. 2015, 27, 914−922. (24) Zou, G. H.; Lin, C. S.; Jo, H.; Nam, G.; You, T. S.; Ok, K. M. Pb2BO3Cl: A Tailor-Made Polar Lead Borate Chloride with Very Strong Second Harmonic Generation. Angew. Chem., Int. Ed. 2016, 55, 12078−12082. (25) Ok, K. M. Toward the Rational Design of Novel Noncentrosymmetric Materials: Factors Influencing the Framework Structures. Acc. Chem. Res. 2016, 49, 2774−2785. (26) Zhang, W. L.; Cheng, W. D.; Zhang, H.; Geng, L.; Lin, C. S.; He, Z. Z. A Strong Second-Harmonic Generation Material Cd4BiO(BO3)3 Originating from 3-Chromophore Asymmetric Structures. J. Am. Chem. Soc. 2010, 132, 1508−1509. (27) Mao, F. F.; Hu, C. L.; Xu, X.; Yan, D.; Yang, B. P.; Mao, J. G. Bi(IO3)F2: The First Metal Iodate Fluoride with a Very Strong Second Harmonic Generation Effect. Angew. Chem., Int. Ed. 2017, 56, 2151−2155. (28) Zhou, J.; Zhao, J. W.; Wei, Q.; Zhang, J.; Yang, G. Y. Two Tetra-CdII-Substituted Vanadogermanate Frameworks. J. Am. Chem. Soc. 2014, 136, 5065−5071. (29) Reshak, A. H.; Kityk, I. V.; Auluck, S.; Chen, X. A. X-ray Diffraction, Crystal Structure, and Spectral Features of the Optical Susceptibilities of Single Crystals of the Ternary Borate Oxide Lead Bismuth Tetraoxide, PbBiBO4. J. Phys. Chem. B 2009, 113, 6640− 6646. (30) Huang, Y. Z.; Wu, L. M.; Wu, X. T.; Li, L. H.; Chen, L.; Zhang, Y. F. Pb2B5O9I: An Iodide Borate with Strong Second Harmonic Generation. J. Am. Chem. Soc. 2010, 132, 12788−12789. (31) Wang, J. Y.; Zhang, H. J.; Jiang, M. H.; Nikitina, M.; Maltsev, V.; Leonyuk, N. Flux Growth and External Morphology of KTiOPO4 Crystals. Cryst. Growth Des. 2009, 9, 1190−1193. (32) Kirsch, J. E.; Izumi, H. K.; Stern, C. L.; Poeppelmeier, K. R. Synthesis and Characterization of the Face-Sharing Bioctahedral [Mo2O6F3]3‑ Anion. Inorg. Chem. 2005, 44, 4587−4593. (33) Inaguma, Y.; Yoshida, M.; Katsumata, T. A Polar Oxide ZnSnO3 with a LiNbO3-Type Structure. J. Am. Chem. Soc. 2008, 130, 6704−6705. (34) Fukina, D. G.; Suleimanov, E. V.; Yavetskiy, R. P.; Fukin, G. K.; Boryakov, A. V.; Borisov, E. N.; Borisov, E. V.; Surodin, S. I.; Saharov, N. V. Single Crystal Structure and SHG of Defect Pyrochlores CsBVMoO6 (BV=Nb, Ta). J. Solid State Chem. 2016, 241, 64−69. (35) Sykora, R. E.; Ok, K. M.; Halasyamani, P. S.; Albrecht-Schmitt, T. E. Structural Modulation of Molybdenyl Iodate Architectures by Alkali Metal Cations in AMoO3(IO3)(A = K, Rb, Cs): A Facile Route to New Polar Materials with Large SHG Responses. J. Am. Chem. Soc. 2002, 124, 1951−1957. (36) Yu, D. H.; Sun, D. H.; Avdeev, M.; Wu, Q.; Tian, X. X.; Gu, Q. F.; Tao, X. T. New High-Pressure Polymorph of the Nonlinear Optical Crystal BaTeMo2O9. Cryst. Growth Des. 2015, 15, 3110− 3113. (37) Chen, C. T.; Wu, B. C.; Jiang, A. D.; You, G. M. A New Type Ultraviolet SHG Crystal β-BaB2O4. Sci. Sin. B 1985, 28, 235−243. (38) Becker, P. Borate Materials in Nonlinear Optics. Adv. Mater. 1998, 10, 979−992. (39) Sasaki, T.; Mori, Y.; Yoshimura, M.; Yap, Y. K.; Kamimura, T. Recent Development of Nonlinear Optical Borate Crystals: Key Materials for Generation of Visible and UV Light. Mater. Sci. Eng., R 2000, 30, 1−54. (40) Petermüller, B.; Petschnig, L. L.; Wurst, K.; Heymann, G.; Huppertz, H. Synthesis and Characterization of the New Strontium Borogermanate Sr3−x/2B2−xGe4+xO14 (x = 0.32). Inorg. Chem. 2014, 53, 9722−9728. (41) Togashi, T.; Kanai, T.; Sekikawa, T.; Watanabe, S.; Chen, C. T.; Zhang, C. Q.; Xu, Z. Y.; Wang, J. Y. Generation of Vacuumultraviolet Light by an Optically Contacted, Prism-coupled KBe2BO3F2 Crystal. Opt. Lett. 2003, 28, 254−256. (42) Jin, S. F.; Cai, G. M.; Wang, W. Y.; He, M.; Wang, S. C.; Chen, X. L. Stable Oxoborate with Edge-Sharing BO4 Tetrahedra E

DOI: 10.1021/acs.inorgchem.7b02838 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry Synthesized under Ambient Pressure. Angew. Chem., Int. Ed. 2010, 49, 4967−4970. (43) Wu, Y. C.; Sasaki, T.; Nakai, S.; Yokotani, A.; Tang, H. G.; Chen, C. T. CsB3O5: A New Nonlinear Crystal. Appl. Phys. Lett. 1993, 62, 2614−2615. (44) Sasaki, T.; Mori, Y.; Kuroda, I.; Nakajima, S.; Yamaguchi, K.; Watanabe, S.; Nakai, S. Caesium Lithium Borate: A New Nonlinear Optical Crystal. Acta Crystallogr., Sect. C: Cryst. Struct. Commun. 1995, 51, 2222−2224. (45) Hu, Z. G.; Higashiyama, T.; Yoshimura, M.; Mori, Y.; Sasaki, T. Flux Growth of the New Nonlinear Optical Crystal: K2Al2B2O7. J. Cryst. Growth 2000, 212, 368−371. (46) Wu, H. P.; Yu, H. W.; Bian, Q.; Yang, Z. H.; Han, S. J.; Pan, S. L. Borate Fluoride and Fluoroborate in Alkali-Metal Borate Prepared by an Open High-Temperature Solution Method. Inorg. Chem. 2014, 53, 12686−12688. (47) Bräuniger, T.; Pilz, T.; Chandran, C. V.; Jansen, M. Full Differentiation and Assignment of Boron Species in the Electrolytes Li2B6O9F2 and Li2B3O4F3 by Solid-state 11B NMR Spectroscopy. J. Solid State Chem. 2012, 194, 245−249. (48) Andriyevsky, B.; Doll, K.; Pilz, T.; Jansen, M. DFT-based ab initio Study of Electronic Band Structure and Elastic Properties of Li2B3O4F3 and Li2B6O9F2 Crystals. J. Phys. Chem. Solids 2013, 74, 624−629. (49) Pilz, T.; Nuss, H.; Jansen, M. Li2B3O4F3, a New Lithium-Rich Fluorooxoborate. J. Solid State Chem. 2012, 186, 104−108. (50) Pilz, T.; Jansen, M. Li2B6O9F2, a New Acentric Fluorooxoborate. Z. Anorg. Allg. Chem. 2011, 637, 1−6. (51) Zhang, B. B.; Shi, G. Q.; Yang, Z. H.; Zhang, F. F.; Pan, S. L. Fluorooxoborates: Beryllium-Free Deep-Ultraviolet Nonlinear Optical Materials without Layered Growth. Angew. Chem., Int. Ed. 2017, 129, 3974−3977. (52) Cakmak, G.; Nuss, J.; Jansen, M. LiB6O9F, the First Lithium Fluorooxoborate Crystal Structure and Ionic Conductivity. Z. Anorg. Allg. Chem. 2009, 635, 631−636. (53) Andriyevsky, B.; Doll, K.; Cakmak, G.; Jansen, M.; Niemer, A.; Betzler, K. DFT-based ab Initio Study of Structural and Electronic Properties of Lithium Fluorooxoborate LiB6O9F and Experimentally Observed Second Harmonic Generation. Phys. Rev. B: Condens. Matter Mater. Phys. 2011, 84, 125112. (54) Cakmak, G.; Pilz, T.; Jansen, M. Na3B3O3F6: Synthesis, Crystal Structure, and Ionic Conductivity. Z. Anorg. Allg. Chem. 2012, 638, 1411−1415. (55) Shi, G. Q.; Zhang, F. F.; Zhang, B. B.; Hou, D. W.; Chen, X. L.; Yang, Z. H.; Pan, S. L. Na2B6O9F2: A Fluoroborate with Short Cutoff Edge and Deep-Ultraviolet Birefringent Property Prepared by an Open High-Temperature Solution Method. Inorg. Chem. 2017, 56, 344−350. (56) Wang, X. F.; Wang, Y.; Zhang, B. B.; Zhang, F. F.; Yang, Z. H.; Pan, S. L. CsB4O6F: A Congruent-Melting Deep-Ultraviolet Nonlinear Optical Material with Superior Functional Units Recombination. Angew. Chem., Int. Ed. 2017, 56, 14119−14123. (57) SAINT, version 7.60A; Bruker Analytical X-ray Instruments, Inc.: Madison, WI, 2008. (58) Sheldrick, G. M. SHELXTL, version 6.14; Bruker Analytical Xray Instruments, Inc.: Madison, WI, 2003. (59) Tauc, J. Absorption Edge and Internal Electric Fields in Amorphous Semiconductors. Mater. Res. Bull. 1970, 5, 721−729. (60) Clark, S. J.; Segall, M. D.; Pickard, C. J.; Hasnip, P. J.; Probert, M. J.; Refson, K.; Payne, M. C. First-principles Methods Using CASTEP. Z. Kristallogr. - Cryst. Mater. 2005, 220, 567−570. (61) Lee, M.-H. Ph.D. Thesis, The University of Cambridge, Cambridge, U.K., 1996. (62) Lin, J.; Qteish, A.; Payne, M.; Heine, V. Optimized and Transferable Nonlocal Separable ab Initio Pseudopotentials. Phys. Rev. B: Condens. Matter Mater. Phys. 1993, 47, 4174−4180. (63) Rappe, A.; Rabe, K.; Kaxiras, E.; Joannopoulos, J. Optimized Pseudopotentials. Phys. Rev. B: Condens. Matter Mater. Phys. 1990, 41, 1227−1230.

(64) Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized Gradient Approximation Made Simple. Phys. Rev. Lett. 1996, 77, 3865−3868. (65) Han, S. J.; Wang, Y.; Pan, S. L.; Dong, X. Y.; Wu, H. P.; Han, J.; Yang, Y.; Yu, H. W.; Bai, C. Y. Noncentrosymmetric versus Centrosymmetric: Influence of the Na+ Substitution on Structural Transition and Second-Harmonic Generation Property. Cryst. Cryst. Growth Des. 2014, 14, 1794−1801. (66) He, M.; Chen, X. L.; Okudera, H.; Simon, A. (K1‑xNax)2Al2B2O7 with 0 ≤ x < 0.6: A Promising Nonlinear Optical Crystal. Chem. Mater. 2005, 17, 2193−2196. (67) Yu, H. W.; Pan, S. L.; Wu, H. P.; Yang, Z. H.; Dong, L. Y.; Su, X.; Zhang, B. B.; Li, H. Y. Effect of Rigid Units on the Symmetry of the Framework: Design and Synthesis of Centrosymmetric NaBa4(B5O9)2F2Cl and Noncentrosymmetric NaBa4(AlB4O9)2Br3. Cryst. Growth Des. 2013, 13, 3514−3521. (68) McMillen, C. D.; Kolis, J. W. Hydrothermal Synthesis and Crystal Structures of Two Novel Acentric Mixed Alkaline Earth Metal Berylloborates Sr3Be2B5O12(OH) and Ba3Be2B5O12(OH). Inorg. Chem. 2011, 50, 6809−6813. (69) Liu, L. L.; Su, X.; Yang, Y.; Pan, S. L.; Dong, X. Y.; Han, S. J.; Zhang, M.; Kang, J.; Yang, Z. H. Ba2B10O17: a New Centrosymmetric Alkaline-earth Metal Borate with a Deep-UV Cut-off Edge. Dalton Trans. 2014, 43, 8905−8910.

F

DOI: 10.1021/acs.inorgchem.7b02838 Inorg. Chem. XXXX, XXX, XXX−XXX