Communication Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX
pubs.acs.org/IC
Targeted Synthesis of Uranium(IV) Thiosilicates Vladislav V. Klepov, Mark D. Smith, and Hans-Conrad zur Loye* Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
Downloaded by ALBRIGHT COLG at 10:03:49:736 on June 12, 2019 from https://pubs.acs.org/doi/10.1021/acs.inorgchem.9b01307.
S Supporting Information *
In this Communication, we report on the synthesis, structures, and properties of Cs2Na4[U2(SiS4)2(Si2S8)] (1) and Cs2.12Na3.88[U2(SiS4)2(Si2S7)] (2), the first uranium(IV) thiosilicates obtained in a controlled reaction. Both compounds were crystallized from an iodide flux employing uranium(IV), silicon(IV), and sodium sulfides as starting reagents. The two novel crystal structures exhibit similar edgesharing uranium chains that are connected by thiopyrosilicate Si2S76− and unprecedented Si2S86− units (Figure 1) into sheets
ABSTRACT: Two new uranium(IV) thiosilicates, Cs2Na4[U2(SiS4)2(Si2S8)] and Cs2.12Na3.88[U2(SiS4)2(Si2S7)], were obtained by flux crystal growth using SiS2 as a silicon source. The former compound contains a novel Si2S86− unit that features a terminal persulfide group. The magnetic susceptibility measurements performed on this compound revealed paramagnetic behavior with a moment of 3.49 μB per uranium atom as obtained from a Curie−Weiss law fit and showed no magnetic transition down to 2 K. The structures are based on closely related isomeric planar and 3D topologies that can be transformed into one another by a rotation of the structural units.
D
espite recent advances in the development of structure and property prediction methodologies, exploratory synthesis of new materials still plays a pivotal role in modern chemistry and materials science. Based mainly on the trial-anderror approach, it can be greatly enhanced by incorporating existing chemical knowledge, such as chemical trends deduced from related chemical systems, and syntheses and, thereby, results in a more effective, targeted synthesis route. One such synthetic route that often results in single crystals is flux crystal growth. This method allows for short reaction times, access to thermodynamic and kinetic products, high-quality crystals, high yields, and phase purity; as a bonus, by benefiting from prior knowledge, it significantly improves the efficiency of exploratory syntheses, successfully paving the way to new materials and greatly facilitating the investigation of their physical properties.1−5 Numerous uranium chalcogenide compounds exhibiting complex structures, promising magnetic and electronic properties, and rare oxidation states6−11 have been obtained from sulfide, halide, and other fluxes.12−22 Driven by interest in the magnetic properties of uranium(IV) compounds that offer a convenient probe for the magnetic behavior of 5f electrons, we have applied the iodide flux crystal growth approach to uranium(IV) thiophosphates and obtained a new family of compounds with complex topologies.23 Extending this approach to new families of uranium compounds, we performed several syntheses involving silicon sulfide in an attempt to increase the content of positively charged countercations and extend the uranium thioanion framework by replacing PS43− anions with SiS44−. It is worth noting that no uranium thiosilicates were known until 2015 when Mesbah et al. serendipitously obtained Ba8Si2US14 and Ba8SiFeUS14, where the silica tubes that contained the reaction served as the silicon source.24 © XXXX American Chemical Society
Figure 1. Disordered Si2S86− and Si2S76− units in the structures of 1 (left) and 2 (right). Sulfur and silicon atoms are yellow and gray, respectively.
or a framework. Magnetic susceptibility measurements revealed paramagnetic behavior of 1, and its UV−vis spectrum is similar to that of uranium(IV) thiophosphate compounds. Both compounds were obtained via the flux crystal growth method using alkali iodide fluxes.25 For both reactions, the choice of the starting materials was made based on the need to achieve reduced reaction times and to ensure that the desired oxidation states of the components would be maintained. We obtained both silicon and uranium sulfides by a direct reaction between the elements (see the Supporting Information for a detailed description). The starting materials, US2, SiS2, and Na2S, were then reacted in evacuated flame-sealed silica tubes containing the cesium iodide (CsI) fluxes. 2 was obtained from a CsI/sodium iodide (NaI) eutectic flux (48.6 mol % NaI; mp 420 °C) as an intimate mixture of the thiosilicate product and the UOS byproduct, the presence of which prevented the property measurements of 2. A sample of 1 contaminated with a minor US3 impurity was isolated from a pure CsI flux. The thiosilicate products were found to be air-sensitive and decomposed in humid air in less than 12 h. To probe the influence of the SiS2 starting material on the reaction outcome and to check the reproducibility of the syntheses, we performed additional reactions using a CsI/NaI eutectic flux along with a control reaction using the same molar ratio of elemental silicon and sulfur. The initial reaction was Received: May 3, 2019
A
DOI: 10.1021/acs.inorgchem.9b01307 Inorg. Chem. XXXX, XXX, XXX−XXX
Communication
Inorganic Chemistry
bond distances in other reported compounds.28 The Si2S86− unit is disordered over two positions by an inversion center and edge-shares with two uranium atoms on one end and two on the other, using all of its six terminal sulfur atoms for bonding. Despite the rich structural chemistry of silicon oxide materials, which exhibit numerous structural units, ranging from the simple orthosilicate SiO44− through complex chain and layered motifs to 3D SiO2, the library of known thiosilicate units is much more sparse and consists of only three examples. Among them, the most common one is the SiS44− anion,29−33 while the other two, Si2S76− and Si2S64−,27,34−37 are much less common. The Si2S86− unit, reported herein for the first time, represents a new addition to the library of thiosilicate units. While the tendency of chalcogenides to form polychalcogenide Qn2− (Q = S, Se, Te) units is well-known,38−40 the data on such units in chalcoanions are rather limited. For example, perselenido bridges have been observed in A4Ge4Se12 (A = Rb, Cs).41 These and other compounds, such as Cs2P4S10,42 exemplify the marked difference between the chalco- and oxoanion chemistry because peroxo groups are rarely present in oxides. Compound 2 crystallizes in a framework structure that consists of uranium atoms connected by thiosilicate SiS4 and thiopyrosilicate Si2S7 units. US8 square antiprisms share edges to form chains, and the bridging thiosilicate units connect them into a 3D framework (Figure 2d). The bond lengths and angles within the US8 coordination polyhedra and thiosilicate units fall within the expected ranges. The thiopyrosilicate units are severely disordered, most likely because of free rotation of the bridging sulfur atom within the unit. The disorder was resolved by introducing many partially occupied sulfur sites and splitting each silicon position into two. Both room- and low-temperature (100 K) data sets resulted in similar models, suggesting that the disorder is either of a static nature or requires even lower temperature to achieve an energy minimum with fully occupied positions. A comparison of the structures reveals a structure formation trend that is similar to that observed in the uranium thiophosphate compounds.23 The uranium polyhedra function as tetracoordinate nodes in both compounds, whereas the SiS4 tetrahedra play the roles of bridging units. In both structures, US8 polyhedra edge-share to form chains that are connected to each other through the thiopyrosilicate units. As schematically shown in Figure 2e, in the layered structure of 1, the chains are parallel to each other. The layers in 1 can be transformed to the 3D framework of 2 by rotating half of the chains, as is shown in Figure 2f, and creating new bonds with the chains from the successive layers. Magnetic susceptibility measurements were performed on 1 and revealed Curie−Weiss behavior in the region of 50−300 K (Figure 3). An effective magnetic moment of 3.49 μB per uranium atom was calculated from a Curie−Weiss fit of the inverse susceptibility data. Given the presence of a minor US3 impurity detected from PXRD, which slightly increases the observed moment of the sample because of the lower molar mass of the impurity, the effective magnetic moment of the uranium atoms in the sample is slightly lower than the value of 3.58 μB calculated for a 3H4 ground state. Despite the presence of infinite edge-sharing uranium(IV) chains in the structure, there is no magnetic transition observed down to 2 K, indicating that the adjacent uranium atoms do not substantially couple magnetically.
found to be reproducible with the use of SiS2 as a silicon source, whereas the reaction involving elemental silicon and sulfur did not result in 2 according to powder X-ray diffraction (PXRD; Figure S2). This suggests that not only is the presence of the proper amount of silicon and sulfur necessary for obtaining the desired uranium thiosilicates but also the chemical forms of the silicon and sulfur play a critical role in influencing the reaction pathway leading to product formation, indicative of a kinetic route to the resulting product. Single crystals of both compounds were analyzed using X-ray diffraction.26 They were found to crystallize in the monoclinic crystal system, space groups C2/m and C2/c for 1 and 2, respectively. 1 exhibits a layered structure composed of U4+ cations connected through SiS44− and Si2S86− anions (Figure 2). The interlayer space is occupied by the alkali cations Cs+
Figure 2. Thiopyrosilicate units in the structures of 1 and 2 (a and b) and connections of US8 coordination polyhedra in sheets and a framework (c and d), respectively, with their schematic representations (e and f). Thiosilicate units SiS4 are omitted for clarity. Sulfur atoms and silicon and uranium polyhedra are yellow, gray, and green, respectively.
and Na+. The uranium atoms form coordination polyhedra in the shape of a distorted tetragonal antiprism with U−S bond lengths ranging from 2.7467(5) to 2.9160(4) Å. Each US8 polyhedron shares two edges with other uranium atoms, forming a US4S4/2 chain along the b axis. In 1, the thiosilicate unit SiS44− adopts a tetrahedral geometry with S−Si−S angles within the range of 106.04(3)−112.15(3)° and Si−S distances of 2.0307(18)−2.1353(10) Å, in good agreement with literature values.24 To the best of our knowledge, the other thiosilicate unit, Si2S86−, has never previously been observed. It consists of two vertex-sharing thiosilicate tetrahedra, as in the thiopyrosilicate unit Si2S76−,27 with one terminal sulfur atom replaced by a persulfide S22− group (Figure 2a). The S−S bond length is 2.1564(16) Å, which is consistent with persulfide B
DOI: 10.1021/acs.inorgchem.9b01307 Inorg. Chem. XXXX, XXX, XXX−XXX
Communication
Inorganic Chemistry Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS Research is supported by the Division of Materials Sciences and Engineering, U.S. Department of Energy, Office of Basic Energy Sciences, under Award DE-SC0018739.
■
Figure 3. Temperature dependence of the molar and inverse molar susceptibilities of 1.
The UV−vis spectrum of 1 has some features in common with the spectra of the previously reported uranium(IV) thiophosphate compounds.18,42 An absorption band at ∼715 nm is associated with ligand-to-metal charge transfer, which was observed at wavenumbers of ∼730 nm in the thiophosphates. 1 absorbs light in the visible region; the absorption slightly decreases at longer wavelengths, which is consistent with the brown/almost black color of the crystals. In summary, two uranium(IV) thiosilicates were obtained via iodide flux crystal growth. The uranium(IV) atoms in both compounds have the same coordination environment. The formation of sheets or a framework in 1 and 2 is achieved through disordered thiopyrosilicate Si2S8 and Si2S7 units, respectively. 1 follows the Curie−Weiss law at higher temperatures and has a magnetic moment of 3.49 μB per uranium atom. A UV−vis spectrum of 1 exhibits features similar to those observed in other uranium(IV) thiophosphates.
■
ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.9b01307. Synthetic procedure, crystallographic details, EDS results, PXRD pattern, SEM images, and a UV−vis spectrum of 1, magnetism, and optical properties (PDF) Accession Codes
CCDC 1899020 and 1899021 contain 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.
■
REFERENCES
(1) Kanatzidis, M. G. Discovery-Synthesis, Design, and Prediction of Chalcogenide Phases. Inorg. Chem. 2017, 56 (6), 3158−3173. (2) Bugaris, D. E.; zur Loye, H.-C. Materials Discovery by Flux Crystal Growth: Quaternary and Higher Order Oxides. Angew. Chem., Int. Ed. 2012, 51 (16), 3780−3811. (3) zur Loye, H.-C.; Besmann, T.; Amoroso, J.; Brinkman, K.; Grandjean, A.; Henager, C. H.; Hu, S.; Misture, S. T.; Phillpot, S. R.; Shustova, N. B.; et al. Hierarchical Materials as Tailored Nuclear Waste Forms: A Perspective. Chem. Mater. 2018, 30 (14), 4475− 4488. (4) Alekseev, E. V.; Krivovichev, S. V.; Depmeier, W. Novel Layered Uranyl Arsenates, Ag6[(UO2)2(As2O7)(As4O13)] and AI6[(UO2)2(AsO4)2(As2O7)] (AI−Ag and Na): First Observation of a Linear As4O136− Anion and Structure Type Evolution. J. Mater. Chem. 2009, 19 (17), 2583. (5) Wu, S.; Wang, S.; Diwu, J.; Depmeier, W.; Malcherek, T.; Alekseev, E. V.; Albrecht-Schmitt, T. E. Complex Clover CrossSectioned Nanotubules Exist in the Structure of the First Uranium Borate Phosphate. Chem. Commun. 2012, 48 (29), 3479. (6) Neuhausen, C.; Rocker, F.; Tremel, W. Modular Metal Chalcogenide Chemistry: Secondary Building Blocks as a Basis of the Silicate-Type Framework Structure of CsLiU(PS4)2. Z. Anorg. Allg. Chem. 2012, 638 (2), 405−410. (7) Hess, R. F.; Abney, K. D.; Burris, J. L.; Hochheimer, H. D.; Dorhout, P. K. Synthesis and Characterization of Six New Quaternary Actinide Thiophosphate Compounds: Cs 8 U 5 (P 3 S 10 ) 2 (PS 4 ) 6, K10Th3(P2S7)4(PS4)2, and A5An(PS4)3, (A = K, Rb, Cs; An = U, Th). Inorg. Chem. 2001, 40 (12), 2851−2859. (8) Van Lierde, W.; Bressers, J. Preparation of Uranium Sulfide Single Crystals. J. Appl. Phys. 1966, 37 (1), 444−444. (9) Kaczorowski, D.; Noël, H.; Potel, M.; Zygmunt, A. Crystal Structure, Magnetic and Electrical Transport Properties of UPS Single Crystals. J. Phys. Chem. Solids 1994, 55 (11), 1363−1367. (10) Gieck, C.; Rocker, F.; Ksenofontov, V.; Gütlich, P.; Tremel, W. Supramolecular” Solid-State Chemistry: Interpenetrating DiamondType Frameworks of U4+ Ions Linked By S,S′-Bidentate P2S62− Molecular Rods in UP4S12. Angew. Chem., Int. Ed. 2001, 40 (5), 908−911. (11) Gieck, C.; Tremel, W. Interlocking Inorganic Screw Helices: Synthesis, Structure, and Magnetism of the Novel Framework Uranium Orthothiophoshates A11U7(PS4)13 (A = K, Rb). Chem. Eur. J. 2002, 8 (13), 2980. (12) Mesbah, A.; Prakash, J.; Beard, J. C.; Malliakas, C. D.; Ibers, J. A. K(Th0.75Sr0.25)2Se6: Structural Change Resulting from the Disorder of Differently Charged Cations. Inorg. Chem. 2018, 57 (13), 7877− 7880. (13) Prakash, J.; Tarasenko, M. S.; Mesbah, A.; Lebègue, S.; Malliakas, C. D.; Ibers, J. A. Synthesis, Crystal Structure, Theoretical, and Resistivity Study of BaUSe3. Inorg. Chem. 2016, 55 (15), 7734− 7738. (14) Prakash, J.; Mesbah, A.; Beard, J. C.; Malliakas, C. D.; Ibers, J. A. Syntheses, Crystal Structures, and Resistivities of the Two New Ternary Uranium Selenides, Er3USe8 and Yb3USe8. J. Solid State Chem. 2016, 233, 90−94. (15) Mesbah, A.; Prakash, J.; Lebègue, S.; Beard, J. C.; Malliakas, C. D.; Ibers, J. A. Ag5U(PS4)3: A Transition-Metal Actinide Phosphochalcogenide. Inorg. Chem. 2019, 58 (1), 535−539. (16) Mesbah, A.; Prakash, J.; Beard, J. C.; Malliakas, C. D.; Lebègue, S.; Ibers, J. A. Syntheses, Modulated Crystal Structures of
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Vladislav V. Klepov: 0000-0002-2039-2457 Hans-Conrad zur Loye: 0000-0001-7351-9098 C
DOI: 10.1021/acs.inorgchem.9b01307 Inorg. Chem. XXXX, XXX, XXX−XXX
Communication
Inorganic Chemistry
(34) Zhbankov, O.; Fedorchuk, A.; Kityk, I.; Olekseyuk, I.; Parasyuk, O. Crystal Structure of the Ag2SiS3 Compound. J. Alloys Compd. 2011, 509 (12), 4372−4374. (35) Choudhury, A.; Ghosh, K.; Grandjean, F.; Long, G. J.; Dorhout, P. K. Structural, Optical, and Magnetic Properties of Na8Eu2(Si2S6)2 and Na8Eu2(Ge2S6)2: Europium(II) Quaternary Chalcogenides That Contain an Ethane-like (Si2S6)6− or (Ge2S6)6− Moiety. J. Solid State Chem. 2015, 226, 74−80. (36) Chen, X.-a.; Wada, H.; Sato, A.; Nozaki, H. Synthesis, Structure, and Electronic Properties of Cu2SiQ3 (Q = S, Se). J. Alloys Compd. 1999, 290 (1−2), 91−96. (37) Mandt, J.; Krebs, B. Darstellung, Struktur und Eigenschaften von Ag10Si3S11. Z. Anorg. Allg. Chem. 1976, 420 (1), 31−39. (38) Sheldrick, W. S. Polychalcogenide Anions: Structural Diversity and Ligand Versatility. Z. Anorg. Allg. Chem. 2012, 638 (15), 2401− 2424. (39) Chung, I.; Do, J.; Canlas, C. G.; Weliky, D. P.; Kanatzidis, M. G. APSe6 (A = K, Rb, and Cs): Polymeric Selenophosphates with Reversible Phase-Change Properties. Inorg. Chem. 2004, 43 (9), 2762−2764. (40) Haynes, A. S.; Saouma, F. O.; Otieno, C. O.; Clark, D. J.; Shoemaker, D. P.; Jang, J. I.; Kanatzidis, M. G. Phase-Change Behavior and Nonlinear Optical Second and Third Harmonic Generation of the One-Dimensional K(1−x)CsxPSe6 and Metastable β-CsPSe6. Chem. Mater. 2015, 27 (5), 1837−1846. (41) Liu, B.-W.; Zhang, M.-Y.; Jiang, X.-M.; Li, S.-F.; Zeng, H.-Y.; Wang, G.-Q.; Fan, Y.-H.; Su, Y.-F.; Li, C.; Guo, G.-C.; et al. Large Second-Harmonic Generation Responses Achieved by the Dimeric [Ge2Se4(μ-Se2)]4− Functional Motif in Polar Polyselenides A4Ge4Se12 (A = Rb, Cs). Chem. Mater. 2017, 29 (21), 9200−9207. (42) Aitken, J. A.; Canlas, C.; Weliky, D. P.; Kanatzidis, M. G. [P2S10]4‑: A Novel Polythiophosphate Anion Containing a Tetrasulfide Fragment. Inorg. Chem. 2001, 40 (25), 6496−6498.
Ba6−2xU2+xAg4Se12 (x = 0 and 0.5), and Crystal Structure and Spectroscopy of Sr4Th2.78Cu4S12. J. Solid State Chem. 2018, 268, 30− 35. (17) Mesbah, A.; Prakash, J.; Ibers, J. A. Overview of the Crystal Chemistry of the Actinide Chalcogenides: Incorporation of the Alkaline-Earth Elements. Dalton Trans 2016, 45 (41), 16067−16080. (18) Babo, J.-M.; Diefenbach, K.; Albrecht-Schmitt, T. E. A6U3Sb2P8S32 (A = Rb, Cs): Quinary Uranium(IV) Thiophosphates Containing the [Sb(PS4)3]6− Anion. Inorg. Chem. 2014, 53 (7), 3540−3545. (19) Babo, J.-M.; Jouffret, L.; Lin, J.; Villa, E. M.; Albrecht-Schmitt, T. E. Synthesis, Structure, and Spectroscopy of Two Ternary Uranium(IV) Thiophosphates: UP2S9 and UP2S7 Containing P2S92− and P2S72− Ligands. Inorg. Chem. 2013, 52 (13), 7747−7751. (20) Alekseev, E. V.; Krivovichev, S. V.; Depmeier, W.; Knorr, K. Complex Topology of Uranyl Polyphosphate Frameworks: Crystal Structures of α-, β-K[(UO2)(P3O9)] and K[(UO2)2(P3O10)]. Z. Anorg. Allg. Chem. 2008, 634 (9), 1527−1532. (21) Hess, R. F.; Gordon, P. L.; Tait, C. D.; Abney, K. D.; Dorhout, P. K. Synthesis and Structural Characterization of the First Quaternary Plutonium Thiophosphates: K3Pu(PS4)2 and APuP2S7 (A = K, Rb, Cs). J. Am. Chem. Soc. 2002, 124 (7), 1327−1333. (22) Neuhausen, C.; Hatscher, S. T.; Panthöfer, M.; Urland, W.; Tremel, W. Comprehensive Uranium Thiophosphate Chemistry: Framework Compounds Based on Pseudotetrahedrally Coordinated Central Metal Atoms: Comprehensive Uranium Thiophosphate Chemistry. Z. Anorg. Allg. Chem. 2013, 639 (15), 2836−2845. (23) Klepov, V. V.; zur Loye, H.-C. Complex Topologies from Simple Building Blocks: Uranium(IV) Thiophosphates. Inorg. Inorg. Chem. 2018, 57 (17), 11175−11183. (24) Mesbah, A.; Prakash, J.; Lebègue, S.; Stojko, W.; Ibers, J. A. Syntheses, Crystal Structures, and Electronic Properties of Ba8Si2US14 and Ba8SiFeUS14. Solid State Sci. 2015, 48, 120−124. (25) Caution! Although the uranium precursor used in this synthesis contains depleted uranium, it is required that proper procedures for handling radioactive materials are observed. All handling of radioactive materials was performed in laboratories specially designated for the study of radioactive actinide materials. (26) Unit cell parameters for Cs2Na4[U2(SiS4)2(S2S8)]: space group C2/m, a = 16.6640(6) Å, b = 9.7115(3) Å, c = 9.1164(3) Å, β = 109.9330(10)°, and R1 = 0.0141. Unit cell parameters for Cs2Na4[U2(SiS4)2(S2S8)]: space group C2/c, a = 16.7459(5) Å, b = 9.6776(3) Å, c = 17.0008(5) Å, β = 97.5250(10)°, and R1 = 0.0208. (27) Schäfer, W.; Scheunemann, K.; Nitsche, R. Crystal Structure and Magnetic Properties of Cu4NiSi2S7. Mater. Res. Bull. 1980, 15 (7), 933−937. (28) Rothenberger, A.; Morris, C.; Kanatzidis, M. G. Synthesis of Alkali Metal Indium Thiophosphates Containing the Discrete Anions [In(PS4)(PS5)2]6− and [In(PS4)2(PS5)]6−. Inorg. Chem. 2010, 49 (12), 5598−5602. (29) Lamarche, A.-M.; Lamarche, G.; Church, C.; Woolley, J. C.; Swainson, I. P.; Holden, T. M. Neutron Diffraction Study of Magnetic Phases in Polycrystalline Mn2SiS4. J. Magn. Magn. Mater. 1994, 137 (3), 305−312. (30) Iyer, A. K.; Yin, W.; Lee, E. J.; Lin, X.; Mar, A. Quaternary Rare-Earth Sulfides RE3M0.5GeS7 (RE = La−Nd, Sm; M = Co, Ni) and Y3Pd0.5SiS7. J. Solid State Chem. 2017, 250, 14−23. (31) Gauthier, G.; Jobic, S.; Evain, M.; Koo, H.-J.; Whangbo, M.-H.; Fouassier, C.; Brec, R. Syntheses, Structures, and Optical Properties of Yellow Ce2SiS5, Ce6Si4S17, and Ce4Si3S12 Materials. Chem. Mater. 2003, 15 (4), 828−837. (32) Gauthier, G.; Kawasaki, S.; Jobic, S.; Macaudiere, P.; Brec, R.; Rouxel, J. Synthesis and Structure of the First Cerium Iodothiosilicate: Ce3(SiS4)2I. J. Alloys Compd. 1998, 275−277, 46−49. (33) Mozolyuk, M. Y.; Piskach, L. V.; Fedorchuk, A. O.; Olekseyuk, I. D.; Parasyuk, O. V.; Khyzhun, O. Y. The Tl2S−PbS−SiS2 System and the Crystal and Electronic Structure of Quaternary Chalcogenide Tl2PbSiS4. Mater. Chem. Phys. 2017, 195, 132−142. D
DOI: 10.1021/acs.inorgchem.9b01307 Inorg. Chem. XXXX, XXX, XXX−XXX
