1312-74-9Relevant articles and documents
New members of the homologous series Am[M6Se8]m [M5+nSe9+n]: The quaternary phases A1-xM′3-xBi11+xSe20 and A1+xM′3-2xBi7+xSe14 (A = K, Rb, Cs; M′ = Sn, Pb)
Mrotzek,Iordanidis,Kanatzidis
, p. 6204 - 6211 (2001)
The compounds A1+xM′3-2xBi7+xSe14 and A1-xM′3-xBi11+xSe20 (A = K, Rb, Cs; M′ = Sn, Pb) were discovered from reactions involving A2Se, Bi2Se3, M′, and Se at 760 °C. The single-crystal structures reveal that A1+xM′3-2xBi7+xSe14 are isostructural to K2.5Bi8.5Se14 whereas A1-xM′3-xBi11+xSe20 adopt a new structure type. Both compound types belong to the homologous series Am[M6Se8]m [M5+nSe9+n] (M = di- and trivalent metal), whose characteristics are three-dimensional anionic frameworks with tunnels filled with alkali ions. The building units are derived from different sections of the NACI lattice, perpendicular to the [111] (NaCl111-type) and [100] (NaCl100-type) directions, respectively, with dimensions and shapes defined by m and n. The structures of A1+xM′3-2xBi7+xSe14 (m = 2, n = 3) and A1-xM′3-xBi11+xSe20 (m = 1, n = 3) exhibit the same type of stepshaped NACl111-type layer but differ in the size of the NaCl100-type unit. In both structures, the Bi and Sn (Pb) atoms are extensively disordered over the metal sites of the chalcogenide network. The physicochemical and charge transport properties of A1+xM′3-2xBi7+xSe14 and A1-xM′3-xBi11+xSe20 (A = K, Rb, Cs; M′ = Sn, Pb) are reported.
APdCu(Se2)(Se3) (A = K and Rb): New quaternary copper palladium polyselenides with unusual metal-selenium coordination
Chen, Xuean,Dilks, Kieran J.,Huang, Xiaoying,Li, Jing
, p. 3723 - 3727 (2003)
Two novel metal polyselenides, KPdCu(Se2)(Se3) (I) and RbPdCu(Se2)(Se3) (II), have been synthesized from solvothermal reactions in superheated ethylenediamine at 160 °C. The isostructural compounds crystallize in the monoclinic space group P21/m, Z = 2, with a = 6.145(1) A, b = 7.268(1) A, c = 8.865(2) A, β = 102.41(3)° for I, and a = 6.253(1) A, b = 7.267(1) A, c = 8.993(2) A, β = 102.28(3)° for II. Their crystal structures are two-dimensional networks with ∞2[PdCu(Se2) (Se3)]- anionic layers built from one-dimensional ∞1[Pd(Se2) (Se3)]2- chains that are stitched together by tetrahedrally coordinated Cu atoms. The DSC data show that I and II are stable up to 400 °C and decompose at ca. 436 and 424 °C, respectively. Both compounds are narrow band-gap semiconductors with estimated band gaps of about 0.7 eV (I) and 0.8 eV (II), respectively. They are the first structurally characterized quaternary copper palladium polychalcogenides with a (Se2)2- and a (Se3)2- fragment, both exhibiting interesting and unusual metal-selenium coordination.
Tropochemical Cell-Twinning in the New Quaternary Bismuth Selenides K xSn6-2xBi2+xSe9 and KSn 5Bi5Se13
Mrotzek, Antje,Kanatzidis, Mercouri G.
, p. 7200 - 7206 (2003)
The quaternary KxSn6-2xBi2+xSe 9 were discovered from reactions involving K2Se, Bi 2Se3, Sn, and Se. The single crystal structures reveal that KxSn6-2xBi2+xSe9 is isostructural to the mineral heyrovskyite, Pb6Bi2S 9, crystallizing in the space group Cmcm with a = 4.2096(4) A, b = 14.006(1) A, and c = 32.451(3) A while KSn5Bi 5Se13 adopts a novel monoclinic structure type (C2/m, a = 13.879(4) A, b = 4.205(1) A, c = 23.363(6) A, β = 99.012(4)°). These compounds formally belong to the lillianite homologous series xPbS·Bi2S3, whose characteristic is derivation of the structure by tropochemical cell-twinning on the (311) plane of the NaCl-type lattice with a mirror as twin operation. The structures of KxSn6-2xBi2+xSe9 and KSn 5Bi5Se13 differ in the width of the NaCl-type slabs that form the three-dimensional arrangement. While cell-twinning of 7 octahedra wide slabs results in the heyrovskyite structure, 4 and 5 octahedra wide slabs alternate in the structure of KSn5Bi5Se 13. In both structures, the Bi and Sn atoms are extensively disordered over the metal sites. Some physicochemical properties of K xSn6-2xBi2+xSe9 and KSn 5Bi5Se13 are reported.
The noncentrosymmetric chain compounds, A3M2AsSe 11 (A = K, Rb, Cs; M = Nb, Ta)
Do, Junghwan,Kanatzidis, Mercouri G.
, p. 41 - 49 (2004)
The noncentrosymmetric niobium and tantalum selenoarsenates, A 3Nb2AsSe11 (A=K, Rb, Cs) and K 3Ta2AsSe11, were synthesized in a polyselenoarsenate flux. All compounds crystallize in the polar monoclinic space group Cc. The structures are comprised of the same type of infinite chain anions, [M2Se2(Se2)3(AsSe 3)]3- (M=Nb, Ta) separated by alkali metal cations. The As3+ centers with nonbonded electron pairs play an important role in stabilizing the noncentrosymmetric structures. UV-Vis spectroscopy, Raman spectroscopy and differential thermal analysis data are reported. The energy gaps of these compounds vary between 1.35 and 1.53eV.
Na2GaS2Cl: A new sodium-rich chalcohalide with two-dimensional [GaS2]∞layers and wide interlayer space
Li, Xiaoshuang,Liang, Fei,Liu, Tianpeng,Li, Haifeng
, p. 11167 - 11172 (2021)
By introducing halogens to the A/Ga/Q (A = Na, K; Q = S, Se) system, one new chalcohalide namely Na2GaS2Cl was successfully obtained. It crystallizes in the orthorhombic space group Cmcm (63). Na2GaS2Cl has a layered structure consisting of two dimensional [GaS2]∞ layers which are stacked in face to face and back to back arrays and separated by Na+ and Cl- ions. Interestingly, supertetrahedral building units [Ga4S10] (T2) which are rarely found in metal chalcogenides and metal chalcohalides are formed in this structure. Moreover, the distances of two adjacent layers are around four times larger than the ionic radius of the Na+ ion, which is very likely to provide a perfect environment for the storage and migration of Na+ ions. In particular, the volume concentration of the Na+ cations in this compound is as high as 1.54 × 1022 cm-3. The UV-vis-NIR spectroscopy measurement reveals that the optical band gap of this title compound is 3.06 eV. The electronic structural calculations on Na2GaS2Cl show that the band gap is mainly determined by the [GaS4] groups and Na-Cl ionic bonding.
Scandium Selenophosphates: Structure and Properties of K4Sc2(PSe4)2(P2Se6)
Syrigos, Jonathan C.,Kanatzidis, Mercouri G.
, p. 4664 - 4668 (2016)
The new compound K4Sc2P4Se14 was synthesized via the polychalcogenide flux method. It crystallizes in the space group C2/c, and the structure is composed of 1/∞[Sc2P4Se144-] chains that are separated by K+ cations. The structural motif features two [PSe4]3- units and one [P2Se6]4- unit bridging the Sc centers and has not been reported for any other compound. The 1/∞[Sc2P4Se144-] chains pack in a crosshatched pattern perpendicular to the c axis of the crystal, forming channels for half of the K+ atoms while the other half occupy empty space between the chains. The orange-yellow crystals of K4Sc2P4Se14 are air-sensitive and gradually turn red over the course of a couple hours. The band gap of the phase is 2.25(2) eV, and Raman spectroscopy shows the symmetric stretches of the selenophosphate groups to be at 231 and 216 cm-1 for the [PSe4]3- and [P2Se6]4- units, respectively. Solid-state 31P MAS NMR of K4Sc2P4Se14 shows two prominent peaks at 11.31 and -23.07 ppm and one minor peak at -106.36 ppm, most likely due to degradation of the product or an unknown second phase.
Synthesis and characterization of KTh2SeE6, KTh2Te6 and CsTh2Se6
Wu, Eric J.,Pell, Michael A.,Ibers, James A.
, p. 106 - 109 (1997)
The compounds KTh2Se6, KTh2Te6 and CsTh2Se6 have been synthesized in the temperature range 873 to 923 K. These compounds are isostructural with the previously synthesized compound CsTh2Te6. They crystallize in the space group D172h-Cmcm of the orthorhombic system with two formula units in cells: a=4.14(2) A, b=21.88(4) A, c=5.64(1) A, V=511(4) A3 (T=298 K) for KTh2Se6; a=4.356(1) A, b =23.702(7) A, c=6.141(2) A, V=634.1(3) A3 for KTh2Te6 (T=113 K); and a=4.14(5) A, b=23.88(4) A, c=5.67(5) A, V=561(13) A3 (T=298 K) for CsTh2Se6. The structure of KTh2Te6 has been determined from single-crystal X-ray data. The structure is composed of 2∞[Th2Te-6] layers that stack perpendicular to [010]. The layers are separated by K+ cations that are coordinated to eight Te atoms at the corners of a rectangular parallelepiped. The K site is one-half occupied. Te atoms form infinite chains within the layers along [001] with Te-Te distances between 3.057(3) A and 3.085(3) A. KTh2Se6, KTh2Te6 and CsTh2Se6 are highly resistive along [100].
Structures and bonding in K0.91U1.79S6 and KU2Se6
Mizoguchi, Hiroshi,Gray, Danielle,Huang, Fu Qiang,Ibers, James A.
, p. 3307 - 3311 (2006)
The compounds K0.91U1.79S6 and KU 2Se6, members of the AAn2Q6 actinide family (A = alkali metal or Tl; An = Th or U; Q = S, Se, or Te), have been synthesized from US2, K2S, and S at 1273 K and U, K 2Se, and Se at 1173 K, respectively. KU2Se6 shows Curie-Weiss behavior above 30 K and no magnetic ordering down to 5 K. The value of μeff is 2.95(1) μB/U. Its electronic spectrum shows the peaks characteristic of 5f-5f transitions. It is a semiconductor with an activation energy of 0.27 eV for electrical conduction. Both K0.91U1.79S6 and KU2Se 6 crystallize in space group lmmm of the orthorhombic system and are of the KTh2Se6 structure type. Both contain infinite one-dimensional linear Q-Q chains characteristic of the AAn2Q 6 family. Typical of the known AAn2Q6 compounds, in KU2Se6, there are two alternating Se-Se distances of 2.703(2) and 2.855(2) A, both much longer than an Se-Se single bond. In contrast, in K0.91U1.79S6, the first sulfide of this family to be characterized structurally, there are alternating normal S22- pairs 2.097(5) A in length. In K0.91U1.79S6, the formal oxidation state of U is 4+.
Functional Chalcogenide Na2HgSn2Se6 and K2MnGe2Se6 Exhibiting Flexible Chain Structure and Intriguing Birefringence Tunability
Li, Zhuang,Lin, Zheshuai,Liu, Youquan,Wu, Yicheng,Xing, Wenhao,Yao, Jiyong,Yin, Wenlong,Zhang, Shengzi
, (2020)
The two functional chalcogenides K2MnGe2Se6 and Na2HgSn2Se6, featuring a straight-chain structure, have been successfully prepared and fully characterized. K2MnGe2Se6 shows paramagnetic behavior. The birefringence of Na2HgSn2Se6 is as large as 0.3107 and derives from the superposition of the polarizabilities of its fundamental building blocks, on the basis of first-principles calculations. Moreover, the flexible framework of the A2MIIMIV2Se6 family enables a variety of heterogeneous substitutions and thus offers possible birefringence tunability, which may inspire the design and exploratory synthesis of IR birefringent materials.
K1.10Zr2Se6, Rb0.86Zr2Se6 and Cs0.80Zr2Se6. The first intercalation compounds of zirconium triselenide
Klepp, Kurt O.,Harringer, Norbert A.,Kolb, Andreas
, p. 1265 - 1269 (2002)
Single crystals of K1.10Zr2Se6, Rb0.86Zr2Se6 and Cs0.80Zr2Se6 were obtained by reacting powdered mixtures of A2Se (A = K, Rb, Cs), Zr and Se at 850°C. K1.10Zr2Se6 and Rb0.86Zr2Se6 crystallize in space group Immm (Z = 2), with a = 3.746(3), b = 5.354(8), c = 21.929(3) A and a = 3.756(1), b = 5.354(8), c = 22.81(1) A?, respectively. Cs0.80Zr2Se6 crystallizes in space group Cmc21 (Z = 2), with a = 3.747(1), b = 24.102(5), c = 5.332(2) A?. The compounds are characterized by complex anionic layers ∞2[Zr2Se6]x- with intercalated alkali cations. As in ZrSe3, the layers are built from columns of trigonal prisms ∞1[ZrSe3], connected by additional waist contacts, yielding an eightfold coordination for the Zr atoms. The mean Zr-Se bond lengths correspond to those found in the binary compound. The Se-Se bond lengths are significantly altered, however, indicating a reduction of the Se-Se bond order due to the electron transfer from the alkali metal.
Semiconducting properties and phase-matching nonlinear optical response of the one-dimensional selenophosphates ANb2PSe10 (A = K, Rb, and Cs)
Syrigos, Jonathan C.,Clark, Daniel J.,Saouma, Felix O.,Clarke, Samantha M.,Fang, Lei,Jang, Joon I.,Kanatzidis, Mercouri G.
, p. 255 - 265 (2015)
The new compounds ANb2PSe10, where A = K, Rb and Cs, form from polyselenophosphate flux reactions and crystallize in the noncentrosymmetric space group Pc. They feature infinite one-dimensional 1/-[Nb2PSe10-] chains separated by alkali cations. The chains consist of [Nb2(Se2)2]4+ clusters bridged by a diselenide and a [PSe4]3- group. The chains pack differently depending on which alkali cation is present in the lattice. As a result, the analogs are not isostructural with respect to each other, and each has a different unit cell. The reaction chemistry involving a multitude of reaction conditions and their respective products is discussed. Other products from these reactions include NbSe3 and Nb2Se9 in both crystalline and microfibrous morphologies. The ANb2PSe10 compounds are stable to oxidation in ambient air but decompose when heated above 350 °C. Their band gaps were measured to be 1.1-1.2 eV and the resistivity of the K analog at room temperature was measured at 4.5 ω·cm. Nonlinear optical second harmonic generation measurements were done on the Rb analog yielding a χ2 of ～7 pm/V and showing phase matching behavior.
Synthesis and characterization of the silver maleonitrilediselenolates and silver maleonitriledithiolates [K([2.2.2]-cryptand)]4[Ag4 (Se2C2(CN)2)4], [Na([2.2.2]-cryptand)]4[Ag4 (S2C2(CN)2)4]·0.33MeCN
McLauchlan,Ibers
, p. 1809 - 1815 (2001)
Reaction of AgBF4, KNH2, K2Se, Se, and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]4[Ag4 (Se2C2(CN)2)4] (1). In the unit cell of 1 there are four [K([2.2.2]-cryptand)]+ units and a tetrahedral Ag4 anionic core coordinated in μ1-Se, μ2-Se fashion by each of four mns ligands (mns = maleonitrilediselenolate, [Se2C2(CN)2]2-). Reaction of AgNO3, Na2(mnt) (mnt = maleonitriledithiolate, [S2C2(CN)2]2-), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)]4[Ag4 (mnt)4]·0.33MeCN (2). The Ag4 anion of 2 is analogous to that in 1. Reaction of AgNO3, Na2(mnt), and [NBu4]Br in acetonitrile yields [NBu4]4[Ag4(mnt)4] (3). The anion of 3 also comprises an Ag4 core coordinated by four mnt ligands, but the Ag4 core is diamond-shaped rather than tetrahedral. Reaction of [K([2.2.2]-cryptand)]3[Ag(mns)(Se6)] with KNH2 and [2.2.2]-cryptand in acetonitrile yields [K([2.2.2]-cryptand)]3[Ag(mns)2]·2MeCN (4). The anion of 4 comprises an Ag center coordinated by two mns ligands in a tetrahedral arrangement. Reaction of AgNO3, 2 equiv of Na2(mnt), and [2.2.2]-cryptand in acetonitrile yields [Na([2.2.2]-cryptand)]3[Ag(mnt)2] (5). The anion of 5 is analogous to that of 4. Electronic absorption and infrared spectra of each complex show behavior characteristic of metal-maleonitriledichalcogenates. Crystal data (153 K): 1, P2/n, Z = 2, a = 18.362(2) A, b = 16.500(1) A, c = 19.673(2) A, β = 94.67(1)°, V = 5941(1) A3; 2, P4, Z = 4, a = 27.039(4) A, c = 15.358(3) A, V = 11229(3) A3; 3, P21/c, Z = 6, a = 15.689(3) A, b = 51.924(11) A, c = 17.393(4) A, β = 93.51(1)°, V = 14142(5) A3; 4, P21/c, Z = 4, a = 13.997(1) A, b = 21.866(2) A, c = 28.281(2) A, β = 97.72(1)°, V = 8578(1) A3; 5, P2/n, Z = 2, a = 11.547(2) A, b = 11.766(2) A, c = 27.774(6) A, β = 91.85(3)°, V = 3772(1) A3.
Hg-Based Infrared Nonlinear Optical Material KHg4Ga5Se12 Exhibits Good Phase-Matchability and Exceptional Second Harmonic Generation Response
Zhou, Molin,Yang, Yi,Guo, Yangwu,Lin, Zheshuai,Yao, Jiyong,Wu, Yicheng,Chen, Chuangtian
, p. 7993 - 8002 (2017)
High-performance infrared (IR) nonlinear optical (NLO) materials with large NLO response and suitable birefringence are urgently needed for various applications. A Hg-based IR NLO material KHg4Ga5Se12 with such desirable properties has been newly discovered. In the structure, obviously distorted HgSe4 and GaSe4 tetrahedra are connected to each other by vertex-sharing to form a three-dimensional framework with the counterion K+ residing in the cavities. Remarkably, all the NLO-active building units in the title compound are arranged in a completely parallel manner. Such a topological structure and the large susceptibility of the Hg-Se bonds enable the material to achieve good phase-matchability with a tremendous powder second harmonic generation (SHG) response at 2.09 μm that is about 20-times that of the benchmark material AgGaS2 (one of the largest responses among all the phase-matchable IR NLO chalcogenides reported to date). The optical band gap of KHg4Ga5Se12 was determined as 1.61 eV. Moreover, on the basis of the electronic band structure, the real-space atom-cutting analysis, the SHG-weighted electronic densities, and the local dipole moments calculations, the origin of the superior linear and nonlinear optical properties of the title compound is ascribed to the (Hg/Ga)Se4 group. The calculated values for the maximum coefficient d33 and birefringence (Δn) at 2.09 μm are -65.257 pm/V and 0.072, respectively. Such values agree well with experimental observations. Our study demonstrates that Hg-based metal chalcogenides are a class of IR NLO material with competitive features (good phase-matchability, very large SHG efficiency, wide transparency) desirable for practical applications.
Structure Tuning, Strong Second Harmonic Generation Response, and High Optical Stability of the Polar Semiconductors Na1- xKxAs Q2
Iyer, Abishek K.,Cho, Jeong Bin,Byun, Hye Ryung,Waters, Michael J.,Hao, Shiqiang,Oxley, Benjamin M.,Gopalan, Venkat,Wolverton, Christopher,Rondinelli, James M.,Jang, Joon I.,Kanatzidis, Mercouri G.
, p. 18204 - 18215 (2021/11/12)
The mixed cation compounds Na1-xKxAsSe2 (x = 0.8, 0.65, 0.5) and Na0.1K0.9AsS2 crystallize in the polar noncentrosymmetric space group Cc. The AAsQ2 (A = alkali metals, Q = S, Se) family features one-dimensional (1D) 1/∞[AQ2-] chains comprising corner-sharing pyramidal AQ3 units in which the packing of these chains is dependent on the alkali metals. The parallel 1/∞[AQ2-] chains interact via short As···Se contacts, which increase in length when the fraction of K atoms is increased. The increase in the As···Se interchain distance increases the band gap from 1.75 eV in γ-NaAsSe2 to 2.01 eV in Na0.35K0.65AsSe2, 2.07 eV in Na0.2K0.8AsSe2, and 2.18 eV in Na0.1K0.9AsS2. The Na1-xKxAsSe2 (x = 0.8, 0.65) compounds melt congruently at approximately 316 °C. Wavelength-dependent second harmonic generation (SHG) measurements on powder samples of Na1-xKxAsSe2 (x = 0.8, 0.65, 0.5) and Na0.1K0.9AsS2 suggest that Na0.2K0.8AsSe2 and Na0.1K0.9AsS2 have the highest SHG response and exhibit significantly higher laser-induced damage thresholds (LIDTs). Theoretical SHG calculations on Na0.5K0.5AsSe2 confirm its SHG response with the highest value of d33 = 22.5 pm/V (χ333(2) = 45.0 pm/V). The effective nonlinearity for a randomly oriented powder is calculated to be deff = 18.9 pm/V (χeff(2) = 37.8 pm/V), which is consistent with the experimentally obtained value of deff = 16.5 pm/V (χeff(2) = 33.0 pm/V). Three-photon absorption is the dominant mechanism for the optical breakdown of the compounds under intense excitation at 1580 nm, with Na0.2K0.8AsSe2 exhibiting the highest stability.
