Exploration of Vanadate Selenites Solid Phase Space, Crystal

Subscriber access provided by OAKLAND UNIV

Article

Exploration of vanadate selenites solid phase space, crystal structures and polymorphism Vadim M. Kovrugin, Marie Colmont, Oleg I. Siidra, Sergey V. Krivovichev, and Olivier Mentre Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.5b01706 • Publication Date (Web): 15 Mar 2016 Downloaded from http://pubs.acs.org on March 17, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Crystal Growth & Design is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Crystal Growth & Design

Exploration of vanadate selenites solid phase space, crystal structures and polymorphism

Vadim M. Kovrugin

a,b

, Marie Colmont a, Oleg I. Siidra b, Sergey V.

Krivovichev b, Olivier Mentré a

a Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France b Department of Crystallography, Institute of Earth Sciences, St. Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia

1 ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Abstract Our recent exploration of the Pb-Ni-Se-O “crystallization phase diagram” in hydrothermal conditions has led to the discovery of three new selenites. Here we have applied a similar systematic method to the Pb-V-Se-O system using both hydrothermal and CVT crystal growth using either PbO or PbCl2 as the source of lead. In our approach, phases in presence are meticulously characterized by single crystal XRD tests, on the basis of their morphology. Besides the determination of stable predominant phases in the diagram such as Pb2(VO3)(SeO3)2Cl, it enables the crystallization of three novel vanadate selenites, β–(V5+2O3)(SeO3)2 (I), Pb2(V4+O)(SeO3)3 (II), and β–Pb4(V5+3O8)2(SeO3)3(H2O) (III), depending on the method, pH and potential of the solution. It is worth noting that in our conditions the solid/liquid crystal growth could be driven by kinetic or thermodynamic control which does not lead to determination of a formal phase diagram, but rather to a “solid-phase space”. The crystal structure of (I) is based on vanadate tetramers linked by selenite groups into a layer. The crystal structures of (II) and (III) contain 1D structural units composed of vanadate polyhedra and selenite groups interlinked through divalent lead cations into a 3D frameworks. The full panorama of reported lead vanadate selenites including our phases shows atypical polymorphic relations discussed on the base of the structural complexity, very atypical between the polymorphic variations.

Keywords: vanadate, selenite, lead, lone electron pairs, polymorphism, crystal structure


Page 2 of 27

Page 3 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1. Introduction The presence of stereochemically active lone electron pair in metal selenites have attracted considerable attention for many years due to their stabilization in a wide range of complex solid architectures with promising physical properties [1–8]. For instance, the research for lead vanadium selenites was recently justified by the ability of such compounds to adopt preferentially noncentrosymmetric (NCS) crystal structures [5,6]. Indeed it is often argued that the association of Se4+, Pb2+ lone-pair electrons and octahedral d0 transition metals (d0 TM), i.e. V5+, Nb5+, all susceptible to second-order Jahn-Teller (SOJT) distortions, appears as the promising route to NCS compounds. Here, lone-pair active cations (Pb2+) or oxo-anions (SeO32–) may favor the organization of the edifice into polar structures. In fact, far from the prediction, the Pb2+– d0 TM – Se4+– O systems (d0 TM = V4+/5+ [4–6], Cu2+ [9,10], Mo/W6+ [11], Nb5+ [4], Fe3+ [12], Ni/Co2+ [13]), on fifteen reported compounds three are effectively NCS, namely β–PbNi(SeO3)2 (space group Cmc21), Pb4(VO2)2(SeO3)4(Se2O5) (space group Fdd2), and the hydrated α–Pb4(V5+3O8)2(SeO3)3(H2O) (space group P21). Dealing with vanadates, the offered multiple coordinations (tetrahedral, pyramidal, octahedral) [14–16] further diversify the complexity of reachable edifices. The vanadium redox (V5+, V4+, V3+) gives even broader opportunities for the prospection of new phases. In the literature, synthesis of inorganic selenites are mainly performed using alternatively either chemical vapor transport (CVT) methods [17–23] or hydrothermal techniques due to good solubility and reactivity of (SeO3)2− anions [1,4–6,13,24]. It is noteworthy that our recent systematic reinvestigation of the Pb2+– Ni2+– Se4+– O crystallization diagram using hydrothermal route yields the discovery of three previously unknown compounds, namely, α–PbM(SeO3)2 (M2+ = Ni, Co), β–PbNi(SeO3)2, and PbNi2(SeO2OH)2(SeO3)2 [13]. In order to complete the rich panorama of lead vanadate selenites, we decided to reinvestigate the Pb2+– V– Se4+– O phase space in the same manner. Taking into account the possibility of incorporation into the crystal structure of large halides acting as scissors due to their preferred association with Pb2+ cations, we have used both PbO and PbCl2 precursors in order to rationalize the domain of growth and stability of the phases in competition. The pertinence of CVT techniques was comforted in recent works, leading to the identification of 6 new phases in the A – Cu+/2+– Se4+– O (A = Pb2+, Na+, K+) system, namely,

K[Cu5O2](SeO3)2Cl3

+

[18],

K[Cu3O](SeO3)2Cl

[19],

Na2[Cu7O2](SeO3)4Cl4

[19],

+

Cu Pb2Cu9O4(SeO3)4Cl7 [20], and KCu Pb0.2Cu5.8O2(SeO3)2Cl6 [20], and NaCu(HSeO3)2Cl [21]. Similar method has been performed with vanadium as TM. Finally in this work, using the two chemical routes aforementioned in the Pb – V – Se – O system, three new phases are described and compared to other known polymorphs when available: (I) β–(V5+2O3)(SeO3)2, (II) Pb2(V4+O)(SeO3)3, and (III) β–Pb4(V5+3O8)2(SeO3)3(H2O). It shows atypical polymorphic relations discussed on the base of the structural complexity.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 27

2. Experimental part 2.1 Pathways for synthesis of lead vanadate selenites There are only six known Pb−V−Se oxides and/or oxyhalides : α-Pb2(V5+2O5)(SeO3)2 [4], Pb2(V4+O)3(SeO3)5

[4],

α-Pb4(V5+O2)2(SeO3)4(Se2O5)

[5],

α–Pb4(V5+3O8)2(SeO3)3(H2O)

[6],

Pb2(V5+O2)(SeO3)2Cl [6], and Pb(V5+O2)(SeO3)F [6]. Most of the compounds have been prepared by hydrothermal techniques at 473–503 K, owing to good solubility and reactivity of Pb2+ and (SeO3)2− anions in aqueous solutions. Using this method, the solution was self-acidified by the product of reaction of SeO2 in water (see below). Various zones of the PbCl2–V2O5–SeO2 and PbO–V2O5–SeO2 systems have been tested. Experimentally, although SeO2 is highly volatile some compounds can be prepared using both hydrothermal treatments and solid state reactions in sealed tubes at moderate temperature, e.g. Pb4(V5+O2)2(SeO3)4(Se2O5) and Pb2(V5+O2)(SeO3)2Cl were prepared as single phases [5,6] at 583 K and 723 K, respectively, in evacuated sealed silica tubes, which provides additional synthetic opportunities using high temperature routes. Here we used CVT reactions emulating the sedimentary exhalative chemistry of minerals [18,25], in which precursors are partially transported by a gaseous agent formed with increasing of temperature from a source zone to a deposition zone under the action of a temperature gradient. This method is well suited to the Pb−V−Se oxide system due to the high volatility of SeO2, and was previously applied to achieve various oxoselenite compounds containing another heavy lone-pair cations such as Bi3+ [17,23,26–29]. Finally, we note that, as already reported by several authors [2,11,13,29–32], an excess of SeO2 is often essential to synthesize mixed-metal oxoselenite compounds in both methods.

2.2 Syntheses Commercial V2O5 (99.6%, Janssen Chimica), SeO2 (99%, Alfa Aesar), PbCl2 (98 %, Aldrich), and PbO (99.999 %, Aldrich), were used as received. 2.2.1 CVT syntheses Single crystals of β–(V5+2O3)(SeO3)2 (I) have been prepared by the chemical vapor transport (CVT) method. A mixture of V2O5 (0.182 g, 1.00 mmol), SeO2 (0.111 g, 1.00 mmol), and PbCl2 (0.139 g, 0.50 mmol), was grounded and loaded into a silica tube (ca. 15 cm), which was further evacuated to 10–3 mbar and sealed. The tube was placed horizontally into a tubular furnace, with the precursor’s bottom placed at the center and heated to 823 K for 7 days and subsequently slowly cooled to room temperature. The temperature ∆T gradient between the source (hot) and deposition (cold) zones of the tube (closed to the edge ) in the furnace was about 50 K. Platy reddish single crystals of I were found in the deposition zone of the tube in association with light orange crystals of V2O5 [33,34]. After


Page 5 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


replacing PbCl2 by PbO in the initial stoichiometric mixture, the same solid products were found in the tube (Fig. 1). 2.2.2 Hydrothermal syntheses Investigation of the crystal growth by using the hydrothermal techniques in the PbCl2–V2O5–SeO2– H2O system included an examination of several combinations of molar ratios of the solid precursors within the Gibbs’ triangle (Fig. 2). In all syntheses, the lPbCl2 + mV2O5 + nSeO2 (l, m, n = 1, 2, ..., 8) molar sum l + m + n was fixed as a constant equal to 2.5 mmol in order to randomly check all zones of the triangle. The mixtures were dissolved in 4 ml of distilled water. The reactions were performed in 23 ml Teflon-lined autoclaves heated at 473 K in ovens. The temperature of autoclaves was held static for 48 hours, followed by cooling to room temperature over 60 hours. The initial and final pHs are ~1 due to the following reactions: SeO2 + H2O H2SeO3 +

(1) –

(2)

2–

(3)

H2SeO3 H + (HSeO3) (pKa = 2.62) –

+

(HSeO3) H + (SeO3) (pKa = 8.32)

The precipitate was filtered through filter paper. In general, we have identified mixture of already reported phases containing V5+ main valence and various Se/Cl ratio depending on the initial composition as discussed below. Crystals of the new compound Pb2(V4+O)(SeO3)3 (II) were grown from a solution of V2O5 (0.046 g, 0.25 mmol), SeO2 (0.222 g, 2.0 mmol), PbCl2 (0.070 g, 0.25 mmol) after addition of couple of drops of hydrazine in 4 ml of distilled water (point P1 in Fig. 2). In this particular case, the pH of the solution evolves from ~1 to ~3 after the reaction. Crystals of II appeared as brown blocks in association with white translucent crystals of γ-Se and already reported Pb3(SeO3)2Cl2 [35]. This compound was initially prepared at 433 K in refluxed solution. Single crystals of the new β–Pb4(V5+3O8)2(SeO3)3(H2O) (III) have been grown in the PbO–V2O5– SeO2–H2O system in association with the crystals of α–Pb4(V5+3O8)2(SeO3)3(H2O) (IV) very recently reported in [6]. A solution of V2O5 (0.109 g, 0.60 mmol), SeO2 (0.067 g, 0.60 mmol), and PbO (0.179 g, 0.80 mmol) in 4 ml of distilled water was used for their preparation. Solid products consisted of platy yellow crystals of III and block-shaped orange crystals of IV (Fig. 3). We note that the singlephase α–form was obtained using PbCO3, V2O5 and SeO2 using KOH in the water solution [6]. However, XRD patterns of the two forms being very similar, the authors may have prepared a mixture of them.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

2.3 Single crystal X-Ray diffraction Single crystals of I, II, and III selected for data collection were examined under optical microscope (Fig. 3a–c) and mounted on glass fibers for single-crystal X-rays diffraction measurements. More than a hemisphere of the X-ray diffraction data were collected for each crystal using a Bruker APEX DUO diffractometer equipped with a micro-focus X-ray tube operated with MoKα radiation at 50 kV and 40 mA. The data were integrated and corrected for absorption using a multi-scan type model using the Bruker programs APEX and SADABS. The crystal structures were solved by direct methods and refined by means of the programs SHELXL–2013 [36]. Crystallographic data are summarized in Table 1. Fractional atomic coordinates, atomic displacement parameters, and selected bond distances are listed in Tables S1–S3, S7–S9, S11–S13 while distances for the α–(V5+2O3)(SeO3)2 polymorph are listed in Table S5 . For the compound III, the hydrogen atoms of the water molecule were localized using difference Fourier map and their presence confirmed by an IR analysis (Fig. 4). The results of the bond-valence sum (BVS) analysis for I, II and III are given in Tables S4, S10, S14. Empirical bond valence parameters required for the BVS calculations for V5+, V4+, Se4+ were taken from Brese and O’Keeffe [37], and for Pb2+ from Krivovichev and Brown [38]. Further details of the crystal structure investigations may be obtained from the Fachinformationszentrum Karlsruhe, 76344 EggensteinLeopoldshafen, Germany (Fax: +49-7247-808-666; e-mail: [email protected], http://www.fizkarlsruhe.de/request_for_deposited_data.html) on quoting the depository numbers CSD–123456, CSD–123456, and CSD–123456 for β–(V2O3)(SeO3)2 (I), Pb2(VO)(SeO3)3 (II), and β– Pb4(V3O8)2(SeO3)3(H2O) (III), respectively.

2.4 Elemental Analysis For the four compounds, Scanning Electron Microscope and Energy Dispersive X-ray (SEM/EDS) analyses were performed on a HITACHI S4700 microscope at 15 kV acceleration voltage and a current of 15 µA at different magnifications. SEM images of the crystals of I, II, III, and IV are shown in Fig. S1-S4. The EDS analyses on several single crystals gave the average Pb : V : Se atomic ratios of 0 : 2.0 : 2.0, 1.8 : 1.0 : 2.8, 3.6 : 5.6 : 3.0, and 3.8 : 5.5 : 3.0 for I, II, III, and IV, respectively. The obtained results are in agreement with those determined from single crystal X-ray analyses. EDS spectra are provided in the Supporting Information File.

2.5 IR Spectroscopy Infrared spectra of I, II, III, and IV were measured between 4000 and 400 cm−1 with a Perkin−Elmer Spectrum 2 spectrometer equipped with a diamond attenuated total reflectance (ATR) accessory. The vibrational bands of vanadate and selenite groups are listed in the Table 2 and IR spectra are provided


Page 6 of 27

Page 7 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


in the Figure 5. Vibrations of water molecules for both α and β–Pb4(V3O8)2(SeO3)3(H2O) (III, IV) are observed while absent for I and II.

3. Results 3.1 Crystallization phase space in the PbCl2/PbO–V2O5–SeO2–H2O systems The formation regions of various crystalline phases are denoted in Fig. 2 by different colors as obtained through scrupulous analysis of the reaction products corresponding to biphasic mixtures. Pb(V5+O3)Cl [39,40] is the most frequent phase that occurs in all hydrothermal experiments in carried out in the PbCl2–V2O5–SeO2–H2O system. The second most common phase, Pb2(V5+O)(SeO3)2Cl, recently reported by Cao et al [6], predominates in the zone with high and moderate selenium concentration. Pb(V5+2O7) [41,42] appears at the left corner of the triangle with a low chloride content, while PbCl2 [43–46] recrystallizes in the right zone of the diagram. Finally, under standard redox conditions, no novel compounds have been found and the solid phase space is dominated by very large domains of crystallization of only four solid phases (V5+ and Se4+), in good agreement with Pourbaix diagrams for vanadium and selenium [47, 48]. General result, as expected, demonstrates formation mechanisms controlled by the solution concentrations of each species. In order to modify the equilibrium, we have added hydrazine to the PbCl2 : V2O5 : SeO2 = 1 : 1 : 8 mixture (point P1 point in Fig. 2). From the Pourbaix diagrams, reducing conditions induced by hydrazine should favor stabilization of V4+ oxo-anions and metal Se. Indeed, we have isolated single crystals of Pb2(V4+O)(SeO3)3 (II), Pb3(SeO3)2Cl2 [35], and γ–Se [49,50]. Another reason for the reduction of metals could be the counter-reduction of the oxidation process of a significant amount of SeO2 during the synthesis, which was already reported e.g. for ZnV4+Se2O7 [1] and Sr2(V4+O)3(SeO3)5 [2]. The use of PbO as the Pb source leads to significantly different results. The points probed for the growth of single crystal phases are illustrated by different colors in the crystallization space the PbO– V2O5–SeO2–H2O system (Fig. 2). Pb(SeO3) [51–54] appeared to be a very stable phase obtained for all tested compositions. Similar results were obtained in our systematic investigation of the NiO–PbO– SeO2 system. In addition, a number of contrasted binary or ternary compounds have been isolated depending in different parts of the crystallization diagram. Once again, the predominance of Pb-based phases demonstrates the strong reactivity of Pb2+ in aqueous solutions, even in Pb–poor areas. β– Pb4(V5+3O8)2(SeO3)3(H2O) is the new phase described here and its crystal structure is detailed below by comparison to those of the α-form. The latter was obtained by Cao et al [6] using hydrothermal



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

techniques under acidic conditions that proves the influence of the thermal conditions and reactive medium in this labile system.

3.3 Structures and polymorphism 3.3.1 (V2O3)(SeO3)2 (I) The new polymorph of (V2O3)(SeO3)2 (I) crystallizes in the monoclinic P21/c space group. Its crystal structure contains two V5+ atoms and two Se4+ atoms. The V1 site is coordinated by six oxygen atoms to form an irregular [1v+4+1t]-octahedron with one short vanadyl bond (V1–O4v = 1.586 Å), and one elongated trans bond (V1–O3t = 2.385 Å). It is noteworthy that three of four equatorial bonds vary in the range from 1.906 Å to 2.006 Å, whereas the fourth bond is noticeably shorter: V1–O3 = 1.783 Å. At the same time, this distance is longer than the average length of 1.66 Å calculated for vanadyl bonds in (V5+O6) configurations [15], refuting the so-called double bond V=O nature. Such coordination with one shortened equatorial bond has been previously observed in the crystal structure of V2O3(SO4)2 [55], as given by comparison for szries of isoformular compounds in Table 3) The V2 site forms a square [1v+4]-pyramid with the average equatorial bonds length of 1.940 Å, and one short vanadyl bond V2–O9v = 1.570 Å. Since the bond-valence contribution of a long distance to the sixth nearest atomic neighbor (V2–O5 = 2.913 Å) does not exceed 0.05 valence units (vu), it is not considered as a sixth ligand of the V2 site. This kind of five-fold coordination has been observed, e.g., in the crystal structures of A4Cd(VO)(V2O7)2Cl (A = Rb, Tl) [56]. Se4+ cations form typical (SeO3)2– triangular pyramids with Se located at its apical corner and a stereoactive lone pair acting as a complementary ligand. The average distance equals 1.704 Å and 1.712 Å for the Se1 and Se2 sites, respectively. The crystal structure is based upon (V4O18)16– tetramers. In these units, a pair of edge-sharing V1 vanadate octahedra shares their common oxygen corners with two V2 square pyramids (Fig. 5a). The selenite anions play different structural roles. Two (Se2O3) triangular pyramids are attached to the tetramer in such a way that selenite triangular O3 bases are relatively parallel to the V–V–V–V plane. The (Se1O3) groups are located in between the vanadate tetramers and provide their linkage into layers through the formation of the Se–O–V links (Fig. 5b). The interlayer spacing is about 3.3 Å and lie parallel to (10-2) plane (Fig. 5c). The layers contain elongated pores with a dimension of 3.0×11.9 Å2, measured between the shortest O···O distances across the pores (Fig. 6a). These slabs are neutral and the cohesion between them is ensured by the lone pair of selenium pointing outward the layers. In Fig. 6b, the 2D metal cationic complex of the crystal structure of (I) is represented as a black-andwhite graph with black and white nodes symbolizing coordination polyhedra of V5+ and Se4+,


Page 8 of 27

Page 9 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


respectively. It highlights a topological structure of the layer composed of 12-membered rings extended approximately along [101] and triple small 4-membered rings of vanadate and selenite groups. Similar 2D topology has been previously observed only in the crystal structure of [Zn2(HPO3)2(C14H14N4)]·0.4H2O [57], where (HPO3) and (ZnO3N) groups share common O corners to form large almost isometric 12-membered (diameter ≈ 7.5Å) and triple small 4-membered rings. Vanadate selenites α–(V2O3)(SeO3)2 [58] and β–(V2O3)(SeO3)2 (I) are two polymorphs. α– and β– forms were prepared by the CVT method at 400°C and 550°C, respectively. In addition, the α– modification was announced to decompose above 400°C into V2O5 and SeO2. It can be suggested that the β–form is a high-temperature modification of (V2O3)(SeO3)2 compared to the α–form. The crystal structures of both polymorphs consist of vanadate tetrameric structural units with different geometry. In the crystal structure of α–modification originally reported by Lee and Kwon [58] the tetramers arrange into chains extended along the a-axis, and composed of (SeO3)2– pyramids and octahedral (V4O18)16– tetramers shown in Fig. 5 d, e. A tetramer is built up from two pairs of edge-shared V5+ octahedra linked through common oxygen equatorial corners. Its V5+ centers have rather regular square planar geometry with the V1···V2 side lengths of 3.41–3.53 Å and the V–V–V angles between 88.7° and 91.3°, see Fig. 5f. In contrast, in the β–form the tetramers are stretched with two mutually perpendicular V1···V1' and V2···V2' distance across the tetramer are 3.20 Å and 6.28 Å, respectively. Geometric distinction can be highlighted by using same dimeric units to description of the tetrameric entities. The tetramer in α– (V2O3)(SeO3)2 represents a pair of two (V2O10)10– dimers composed of edge-shared V5+ octahedra (Fig. 5c), whereas the tetrameric unit of β–(V2O3)(SeO3)2 consists of the same single (V2O10)10– dimer along with two V5+ square pyramids attached at both sides (Fig. 5f). It is noteworthy that isoformular (V2O3)(TeO3)2 [59,60] and (V2O3)(XO4)2 (X = S, Se) [3,53,61] show different metal oxide units, which most plausibly results from the size of the (XOn)2– oxo-anions (Fig. 7, Table 3). The structure of (V2O3)(TeO3)2 contains chains of edge-shared vanadate octahedra interconnected through tellurite groups. These chains are similar to those of pyroxene compounds with general chemical formula AM(Si2O6), where A+ = alkali metal and M3+ = transition metal [62]. In (V2O3)(XO4)2 (X = S, Se) corner-shared pairs of vanadate octahedra are bridged via tetrahedral groups of S6+ or Se6+ into 3D frameworks. Such a wide variety of the crystal structures with similar chemical compositions is typical for distinctive and complex crystal chemistry of vanadate compounds, and can be stabilized by the presence of strong vanadyl and weak V–O bonds in (V5+On) polyhedra. Also contributing is the fact that the stereochemically active s2 electron lone-pair of Se4+, Te4+ could form structural cavities.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 27

3.2.2 Pb2(V4+O)(SeO3)3 (II) This reduced phase contains so-called vanadyl (V=O)2+ ions. Pb2(V4+O)(SeO3)3 crystallizes in the monoclinic P21/n space group. Its crystal structure can be considered as formed from 1D vanadate selenite structural units with divalent Pb cations located in between providing 3D linkage of the structure (Fig. 8a). A unique V4+ atom is octahedrally coordinated by six O atoms. The (VO6)8– octahedron contains one short vanadyl bond V–O7 = 1.615 Å, four equatorial bonds with the average bond length of 2.035 Å, and one shortened trans bond V–O5 = 2.096 Å. Occurrence of such a short trans bond length is rather rare for the compounds with octahedrally coordinated V4+ sites [15], where the trans-bond length is usually more close to 2.2 Å. Nevertheless it has been observed, e.g., in the crystal structures of KVO(PO4) [63] and A2(VO)3(P2O7)2 (A = Rb, K) [64,65]. In both cases, the valence bond of this “long” oxygen corner is completed by bonding to an oxo-anion (SeO3 or P2O7), while the V=O7 oxygen atom is not further bonded apart from Se and leads to a BVS of 1.77 vu (valence units). The three symmetrically independent Se4+ sites form (SeO3)2– triangular pyramids with the average bond lengths of 1.703 Å, 1.707 Å and 1.699 Å for Se1, Se2 and Se3, respectively. The structure of (II) contains two symmetrically independent Pb2+ sites (Fig. 9a, b). All Pb–O distances ≤ 3.5 Å with bond valences ≥ 0.05 vu were considered. Both lead cations are surrounded by ten common O atoms belonging to the (VO6)8– and (SeO3)2– groups. Generally, Pb2+ cations demonstrate short and strong Pb–O bonds in one coordination hemisphere and long weaker Pb–O bonds in another. This coordination is typical for divalent lead with stereochemically active lone electron pair [64,65]. Pb1 has three short strong Pb–O bonds and seven relatively long Pb–O bonds. The average length of short Pb–O bonds equals 2.428 Å, whereas long Pb–O bonds vary from 2.774 Å to 3.234. Asymmetric coordination environment of the Pb2 site demonstrates five short (2.427 Å to 2.647 Å) and five relatively long (2.821 Å to 3.407 Å) Pb–O distances. Detailed results of the BVS calculations for (II) are listed in Table S.12. In the crystal structure of (II), single vanadate octahedra share five of their oxygen corners with adjacent selenite triangular pyramids to form [(VO2)(SeO3)3]4– chains running along the a-axis (Fig. 8b). Both bidentate (Se2O3)2– and (Se3O3)2– groups bridge two adjacent (V1O6)8– octahedra, whereas (Se1O3)2– triangular pyramid is monodentate and share only one corner with trans-one of the vanadate octahedron. The black-and-white graph corresponding to the vanadate selenite chain is shown in Fig. 8c. Similar 1D topology with trans-arrangement of non-bonded white vertices (located alternately in opposite

directions)

has

been

observed

in

the

uranyl

oxysalts:

demesmaekerite

Pb2Cu5(SeO3)6(UO2)2(OH)6·2H2O [68], Na4[(UO2)(CrO4)3] [69], K5[(UO2)(CrO4)3](NO3)(H2O)3 [70], Na3Tl5[(UO2)(MoO4)3]2(H2O)3 and Na13–xTl3+x[(UO2)(MoO4)3]4(H2O)6+x (x = 0.1) [71]. In the structure of (II), the orientation of the 1D structural units can be considered as planar and parallel to (010) with divalent lead cations providing their linkage (Fig. 8a).


Page 11 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


3.2.3 β–Pb4(V3O8)2(SeO3)3(H2O) (III) The α and β polymorphic modifications of Pb4(V3O8)2(SeO3)3(H2O) are very similar from the structural point of view. The novel β-form reported herein crystallizes in the triclinic P–1 space group and is built up from stacking vanadate selenite 1D structural units further bridged by divalent lead cations into a 3D framework (Fig. 10b). There are six independent V5+, three Se4+, and four Pb2+ cations per one unit cell. Pentavalent vanadium cations occupy six-fold (V1, V2, V4 ) and five-fold sites (V3, V5, V6). As for the V1 site in I, the V1, V2 and V4 octahedra display distortions in their equatorial planes expressed by one noticeably short equatorial distance: V1–O21 = 1.757 Å, V2– O22 = 1.731 Å, and V4–O2 = 1.674 Å. For V4, this bond can be as a second vanadyl bond leading to a [1v+(1v+3)+1t]-coordination, a rather original vanadium coordination already observed in the crystal structure of Na6[H2V2I2O16]·10H2O [72]. Finally, vanadyl bonds of V5+ octahedra range from 1.609 Å to 1.674 Å, whereas trans-bonds vary from 2.540 to 2.845 Å. The average equatorial bond lengths are 1.868 Å, 1.891 Å, and 1.886 Å for V1, V2, and V4, respectively. V3, V5, and V6 have a distorted square [1v+(1v+3)]-pyramidal environment with two short vanadyl bonds ( equals 1.643 Å, 1.651 Å, and 1.652 Å for V3, V5, and V6, respectively) and three equatorial bonds ( equals 1.961 Å, 1.956 Å, and 1.930 Å for V3, V5, and V6, respectively). This coordination type of distorted square pyramids of V5+ has been found, e.g., in the crystal structures of Mn(V2O6)(H2O)4 [73], and K[VO2(SO4)(H2O)2](H2O) [74]. The average distances equal 1.711 Å, 1.707 Å, and 1.710 Å for Se1, Se2, and Se3 sites, respectively. For estimation of the coordination of the four crystallographically independent Pb2+ sites (Fig. 9c-f), all Pb–O distances ≤ 3.5 Å (i.e. bond valence contribution ≥ 0.05 vu) were considered. Pb1 and Pb2 cations are surrounded by eight O atoms with six and seven relatively short strong Pb–O bonds in the range 2.497–2.673 Å (0.34–0.24 vu) and 2.408–2.732 Å (0.40–0.21 vu) for Pb1 and Pb2, respectively, Pb3 and Pb4 sites are coordinated by nine O atoms. Six of them are located at relatively short distances of 2.464–2.720 Å (0.36–0.21 vu) and 2.505–2.759 Å (0.33–0.20 vu) for Pb3 and Pb4, respectively, typical of stereoactive 6s2 lonepairs. The bond valance sums for Pb1, Pb2, Pb3 and Pb4 are 2.09 vu, 2.19 vu, 1.93 vu and 1.97 vu, respectively. Bond distances and BVS calculations for (III) are listed in Table S.13 and S.14. The atom O26 located at a distance of 2.616 Å from Pb1 belongs to a water molecule. It links via hydrogen bonding to non-bonded oxygen vertices of the (Se3O3)2– group (O26–O20 = 2.644 Å and O26–O17 = 3.269 Å) (Fig. 10a).



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The crystal structure of (III) is built up from stacking of chiral vanadate/selenite ribbons. Pair of edgesharing V1O6 and V2O6 octahedra are linked via mutually parallel edges with edge-sharing V5O5 and V6O5 square pyramids to form a tetravanadate zigzag [V4O14]8– chain extended along the a axis (Fig. 11a, b). Peripheral V3O5 polyhedron shares one edge with V1O6 octahedron, while on the other side V4O6 octahedra are connected to the chains by sharing one vertex and one edge with V6 and V2, respectively. The asymmetric arch-like vanadate [V6O20]10– ribbon is shown in Fig. 11c, d. Selenite (Se1O3) 2– and (Se2O3)2– triangular pyramids are linked via common single vertices to the V4 and V3 polyhedra, respectively, and act as monodentate terminal ligands on both sides of the ribbon. The (Se3O3)2– triangular pyramid is attached to the middle part of the ribbon by bidentate bridging between apical vertices of the V1 and V2 octahedra, thus slightly bending the ribbon along the a-axis (Fig. 11e, f). It is of interest that both the α– and β–polymorphs contain the aforementioned chiral ribbons, but their mutual arrangements are different. In the triclinic β–structure (S.G. P–1), one of the ribbons is inverted with respect to the other by a symmetry center (designated as A and A-1) (Fig. 12a,b). Adjacent chiral ribbons are linked via strong metal oxide Se–O–Pb3 and Pb4–O–V linkages to form 2D structural units parallel to (010) (Fig. 10a). The Pb1 and Pb2 atoms provide additional interconnection of the layers into a 3D framework (Fig. 10b). Water molecules and hydrogen bonding do not participate in the connection of adjacent structural units, and they fill the remaining void space in the structure. On the opposite, the monoclinic α–Pb4(V3O8)2(SeO3)3(H2O) (IV) recently described by Cao et al [6] (Fig. 10a) crystallizes in the monoclinic noncentrosymmetric P21 space group, where two adjacent vanadate selenite ribbons (designated as A and A21) are symmetrically related by the 21 screw axis (Fig.12a,b). Crystal structures of both polymorphs are very similar and based upon stacking of 1D vanadate selenite units. Divalent lead cations bridge them into 3D framework, and water molecules fill the remaining void space. They have very close unit-cell parameters with approximately equal volume: 1091.02(3) Å3 and 1091.12(6) Å3 for α– and β–modification, respectively. The mode of packing of the vanadate selenite ribbons along the b- and c-axis for the two forms remains the same in both polymorphic modifications, (Fig. 12) and is achieved by SeO3 groups common in the two structures, which is very rare to the best of our knowledge. In the structure of α– polymorph, the ribbon A is connected to adjacent rotated ribbon A21 forming a layer composed of alternating ribbons in a …AA21AA21A… sequence (Fig. 12b). The structure of III has a …AA-1AA1

A… stacking sequence of the vanadate selenite ribbons (Fig. 12a). Adjacent layers of the same

sequences in both structures are placed directly under each other.


Page 12 of 27

Page 13 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


3.3 Polymorphism and structural complexity It is of interest to compare polymorphic variations in the system under study from the viewpoint of structural complexity that can be estimated as a Shannon information content per atom (IG) and per unit cell (IG,total). According to this approach, complexity of a crystal structure can be quantitatively characterized by the amount of Shannon information it contains measured in bits (binary digits) per atom (bits/atom) and per unit cell (bits/cell), respectively. The concept of Shannon information, also known as Shannon entropy, employed here originates from the information theory [75] and its application to various problems in graph theory, chemistry, biology, etc. [76]. The amount of Shannon information reflects diversity and relative proportion of different objects, e.g., the number and relative proportion of different sites in an elementary unit cell of a crystal structure. For a crystal structure, the calculation involves the use of the following equations [77,78]: IG = –∑ i log2 pi

(bits/atom)

IG,total = – v IG = – v∑ i log2 pi

(1),

(bits/cell)

(2),

where k is the number of different crystallographic orbits (independent crystallographic Wyckoff sites) in the structure and pi is the random choice probability for an atom from the ith crystallographic orbit, that is: pi = mi / v

(3),

where mi is a multiplicity of a crystallographic orbit (i.e. the number of atoms of a specific Wyckoff site in the reduced unit cell), and v is the total number of atoms in the reduced unit cell. It has recently been shown [79] that the IG value provides a negative contribution to the configurational entropy (Scfg) of crystalline solids in accordance with the general principle that the increase in structural complexity corresponds to the decrease of the Scfg value. It is noteworthy that the information-based metrics of structural complexity are identical for the two pairs of polymorphs reported herein: IG = 3.700 bits/atom and IG,total = 192.423 bits/cell for α- and β– (V2O3)(SeO3)2, and IG = 5.358 bits/atom and IG,total = 439.319 bits/cell for the two polymorphic modifications

of

Pb4(V3O8)2(SeO3)3(H2O).

The

higher

structural

complexity

of

the

Pb4(V3O8)2(SeO3)3(H2O) phases compared to the (V2O3)(SeO3)2 phases is obviously the result of their higher chemical complexity. The former contain five different chemical elements in their formulae, whereas the latter contain only three. Identical structural complexity for the two polymorphs of (V2O3)(SeO3)2 is remarkable, since their crystal structures are topologically very different. It is, however, of interest that the presumably hightemperature β–modification has a layered character, while the α-phase consists of a three-dimensional framework. This kind of structural difference is in agreement with the earlier observations



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

exemplified, e.g., by the BiSeO3Cl polymorphs [80]. Since no direct phase transition pathway was observed or can be inferred for the two phases, we suggest that the polymorphism here is the result of the presence of PbCl2 in a synthetic mixture used to prepare the β–phase in this study, which may induce formation of different kinds of precursor phases or clusters in the gaseous phase during the CVT experiment. In contrast to (V2O3)(SeO3)2, two polymorphs of Pb4(V3O8)2(SeO3)3(H2O) are based upon the same type of vanadate selenite ribbons and differ in their stacking modes only. Consequently, the two compounds represent the case of ‘rod polytypism’, which is well-known for structures based upon the same type of 1D structural units [79]. Therefore, it is not surprising that the structures of α– and β– Pb4(V3O8)2(SeO3)3(H2O) have the same level of structural complexity.

4. Concluding remarks We successfully synthesized and characterized three new compounds α–(V2O3)(SeO3)2 (I), Pb2(V4+O)(SeO3)3 (II) and Pb4(V3O8)2(SeO3)3(H2O) (III). (I) and (II) are polymorphs of phases already reported which proves the versatility of selenite based frameworks and strong dependence of the synthesis conditions and favored phases in the solid phase space. The systematic exploration of such “crystallization” diagram shows the competition that exists between various lattices and the needs for a scrupulous screening of several parameters for the elaboration of novel phases. For instance it was possible to isolate a second (β) form of Pb4(V5+3O8)2(SeO3)3(H2O) prepared simultaneously with the priory reported α- polytype. In particular, in terms of complexity it is striking that both α- and β–Pb4(V5+3O8)2(SeO3)3(H2O) (III) as well as α- and β–(V2O3)(SeO3)2 pairs have exactly the same degree of complexity although very different topological arrangement in the latter. It highlight the chemical richness and various edifices possibly reached by the association oxo-anions such as SeO3 and VOn when associated with versatile cations such as lonepair Pb2+ ones.

Acknowledgements This work was carried out under the framework of the Multi-InMaDe project supported by the ANR (Grant ANR 2011-JS-0800301). The Fonds Européen de Développement Régional (FEDER), CNRS, Région Nord Pas-de-Calais, and Ministère de l’Education Nationale de l’Enseignement Supérieur et de la Recherche are acknowledged for funding the X-ray diffractometers. V.M.K. thanks l’Ambassade de France en Russie and l’Agence Campus France (Contract Nos. 768231K, 779116K, 794852B, 808399A, and 808400J) for the partial support of this work. S.V.K. and O.I.S. acknowledge financial support from St. Petersburg State University (Internal Grant 3.38.136.2014). Chevreul Institute (FR


Page 14 of 27

Page 15 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


2638), Ministère de l’Enseignement Supérieur et de la Recherche, Région Nord – Pas de Calais and FEDER are acknowledged for supporting and funding partially this work.

Supporting informations :

The supporting information is available free of charge on the ACS publication website at DOI **********. It includes elemental analyzes and crystallographic informations.

References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23]

[24] [25] [26]

H.L. Jiang, F. Kong, Y. Fan, J.-G. Mao, Inorg. Chem. 47 (2008) 7430–7437. S.-Y. Zhang, C.-L. Hu, C.-F. Sun, J.-G. Mao, Inorg. Chem. 49 (2010) 11627–11636. A.P. Tyutyunnik, V.N. Krasil’nikov, V.G. Zubkov, L.A. Perelyaeva, I. V. Baklanova, Russ. J. Inorg. Chem. 55 (2010) 501–507. P.-X. Li, F. Kong, C.-L. Hu, N. Zhao, J.-G. Mao, Inorg. Chem. 49 (2010) 5943–5952. J. Yeon, S. Kim, S.D. Nguyen, H. Lee, P.S. Halasyamani, Inorg. Chem. 51 (2012) 609–619. X.-L. Cao, F. Kong, C.-L. Hu, X. Xu, J.-G. Mao, Inorg. Chem. 53 (2014) 8816–8824. Y.H. Kim, D.W. Lee, K.M. Ok, Inorg. Chem. 52 (2013) 11450–11456. T. Eaton, J. Lin, J.N. Cross, J.T. Stritzinger, T.E. Albrecht-Schmitt, Chem. Commun. 50 (2014) 3668–3670. H. Effenberger, J. Solid State Chem. 73 (1988) 118–126. H. Effenberger, Mineral. Petrol. 36 (1987) 3–12. S.-J. Oh, D.W. Lee, K.M. Ok, Dalt. Trans. 41 (2012) 2995. M.G. Johnston, W.T.A. Harrison, J. Solid State Chem. 177 (2004) 4680–4686. V.M. Kovrugin, M. Colmont, C. Terryn, S. Colis, O.I. Siidra, S. V. Krivovichev, O. Mentré, Inorg. Chem. 54 (2015) 2425–2434. H.T.J. Evans, J.M. Hughes, Am. Mineral. 75 (1990) 508–521. M. Schindler, F.C. Hawthorne, W.H. Baur, Chem. Mater. 12 (2000) 1248–1259. S. Boudin, A. Guesdon, A. Leclaire, M.-M. Borel, Int. J. Inorg. Mater. 2 (2000) 561–579. A. Aliev, V.M. Kovrugin, M. Colmont, C. Terryn, M. Huvé, O.I. Siidra, S. V. Krivovichev, O. Mentré, Cryst. Growth Des. 14 (2014) 3026–3034. V.M. Kovrugin, O.I. Siidra, M. Colmont, O. Mentré, S. V. Krivovichev, Mineral. Petrol. 109 (2015) 421–430. V.M. Kovrugin, M. Colmont, O. Mentré, O.I. Siidra, S. V. Krivovichev, Mineral. Mag. (2015) accepted. V.M. Kovrugin, M. Colmont, O.I. Siidra, O. Mentré, A. Al-Shuray, V. V. Gurzhiy, S. V. Krivovichev, Chem. Commun. 51 (2015) 9563–9566. V.M. Kovrugin, S. V. Krivovichev, O. Mentré, M. Colmont, Z. Kristallogr. 230 (2015) 573– 577. P.S. Berdonosov, O. Janson, A. V Olenev, S. V. Krivovichev, H. Rosner, V.A. Dolgikh, A.A. Tsirlin, Dalton Trans. 42 (2013) 9547–54. P.S. Berdonosov, E.S. Kuznetsova, V.A. Dolgikh, A. V Sobolev, I.A. Presniakov, A. V Olenev, B. Rahaman, T. Saha-Dasgupta, K. V Zakharov, E.A. Zvereva, O.S. Volkova, A.N. Vasiliev, Inorg. Chem. 53 (2014) 5830–5838. S.-Y. Zhang, C.-L. Hu, J.-G. Mao, Dalton Trans. 41 (2012) 2011–7. M. Binnewies, R. Glaum, M. Schmidt, P. Schmidt, Z. Anorg. Allg. Chem. 639 (2013) 219– 229. P.S. Berdonosov, S.Y. Stefanovitch, V.A. Dolgikh, J. Solid State Chem. 149 (2000) 236–241.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

[27] [28]

S.-Y. Zhang, C.-L. Hu, P.-X. Li, H.-L. Jiang, J.-G. Mao, Dalton Trans. 41 (2012) 9532–9542. P.S. Berdonosov, A. V. Olenev, M.A. Kirsanova, J.B. Lebed, V.A. Dolgikh, J. Solid State Chem. 196 (2012) 232–237. [29] E.P. Lee, S.Y. Song, D.W. Lee, K.M. Ok, Inorg. Chem. 52 (2013) 4097–4103. [30] R. Frydrych, Z. Anorg. Allg. Chem. 427 (1976) 260–264. [31] G. Steinhauser, C. Luef, M. Wildner, G. Giester, J. Alloys Compd. 419 (2006) 45–49. [32] S. Oh, D.W. Lee, K.M. Ok, Inorg. Chem. 51 (2012) 5393–5399. [33] H.G. Bachmann, F.R. Ahmed, W.H. Barnes, Z. Kristallogr. 115 (1961) 110–131. [34] J. Haber, M. Witko, R. Tokarz, Appl. Catal. A Gen. 157 (1997) 3–22. [35] Y. Porter, P.S. Halasyamani, Inorg. Chem. 40 (2001) 2640–2641. [36] G.M. Sheldrick, Acta Crystallogr. A64 (2008) 112–22. [37] N.E. Brese, M. O’Keeffe, Acta Crystallogr. B47 (1991) 192–197. [38] S. V. Krivovichev, I.D. Brown, Z. Kristallogr. 216 (2001) 245–247. [39] A. Sahin, M. Emirdag-Eanes, Zeitschrift Für Krist. - New Cryst. Struct. 222 (2007) 159–160. [40] V. Jo, M.K. Kim, I.-W. Shim, K.M. Ok, Bull. Korean Chem. Soc. 30 (2009) 2145–2148. [41] A. Kawahara, Bull. Soc. Franç. Minér. Cris. 90 (1967) 279–284. [42] R.D. Shannon, C. Calvo, Can. J. Chem. 51 (1973) 70–76. [43] H. Brackken, Z. Kristallogr. 83 (1932) 222–226. [44] K. Shal, Beiträge Zur Mineral. Und Petrogr. 9 (1963) 111–132. [45] E.B. Brackett, T.E. Brackett, R.L. Sass, J. Phys. Chem. 67 (1963) 2863–2864. [46] J.M. Leger, J. Haines, A. Atouf, J. Phys. Chem. Solids 57 (1996) 7–16. [47] N. Greenwood, A. Earnshaw Chemistry of the Elements (2nd ed.) (1997) ButterworthHeinemann. p. 984. ISBN 0-08-037941-9. [48] M. Pourbaix Atlas of electrochemical equilibria in aqueous solutions. (1974) National association of corrosion engineers (2nd English Edn.) USA [49] P. Cherin, P. Unger, Inorg. Chem. 6 (1967) 1589–1591. [50] Y. Akahama, M. Kobayashi, H. Kawamura, Phys. Rev. B 47 (1993) 20–26. [51] B.A. Popovkin, V.P. Cheremisinov, Y.P. Simanov, J. Struct. Chem. 4 (1963) 38–43. [52] R. Fischer, TMPM Tschermaks Mineral. Und Petrogr. Mitteilungen 17 (1972) 196–207. [53] M. Koskenlinna, J. Valkonen, Cryst. Struct. Commun. 6 (1977) p813–816. [54] M. Pasero, N. Rotiroti, Neues Jahrb. Für Mineral. - Monatshefte 2003 (2003) 145–152. [55] K.L. Richter, R. Mattes, Z. Anorg. Allg. Chem. 611 (1992) 158–164. [56] B. Mertens, H. Müller-Buschbaum, Z. Naturforsch. 52 (1997) 453–456. [57] J. Fan, C. Slebodnick, D. Troya, R. Angel, B.E. Hanson, Inorg. Chem. 44 (2005) 2719–2727. [58] K.-S. Lee, Y.-U. Kwon, J. Korean Chem. Soc. 40 (1996) 379–383. [59] J. Darriet, J. Galy, Cryst. Struct. Commun 2 (1973) 237–238. [60] P. Millet, J. Galy, M. Johnsson, Solid State Sci. 1 (1999) 279–286. [61] J. Tudo, B. Jolibois, G. Laplace, Comptes Rendus l’Académie Des Sci. - Ser. C 269 (1969) 978–980. [62] M. Cameron, S. Sueno, C.T. Prewitt, J.J. Papike, Am. Mineral. 58 (1973) 594–618. [63] L. Benhamada, A. Grandin, M.M. Borel, A. Leclaire, B. Raveau, Acta Crystallogr. C47 (1991) 1138–1141. [64] A. Leclaire, H. Chahboun, D. Groult, B. Raveau, J. Solid State Chem. 77 (1988) 170–179. [65] K.-H. Lii, Y.-P. Wang, C.-Y. Chneg, S.-L. Wang, H.-C. Ku, J. Chinese Chem. Soc. 37 (1990) 141–149. [66] L. Shimoni-Livny, J.P. Glusker, C.W. Bock, Inorg. Chem. 37 (1998) 1853–1867. [67] J. Masternak, B. Barszcz, M. Hodorowicz, O. V. Khavryuchenko, A. Majka, Spectrochim. Acta Part A Mol. Biomol. Spectrosc. 136 (2015) 1998–2007. [68] D. Ginderow, F. Cesbron, Acta Crystallogr. C39 (1983) 824–827. [69] S. V. Krivovichev, P.C. Burns, Z. Anorg. Allg. Chem. 629 (2003) 1965–1968. [70] S. V. Krivovichev, P.C. Burns, Z. Kristallogr. 218 (2003) 725–732. [71] S. V. Krivovichev, P.C. Burns, Can. Mineral. 41 (2003) 707–719. [72] R. Mattes, K.L. Richter, Z. Naturforsch. 37 (1982) 1241–1244. [73] J.H. Liao, T. Drezen, F. Leroux, D. Guyomard, Y. Piffard, Eur. J. Solid State Inorg. Chem. 33 (1996) 411–427.


Page 16 of 27

Page 17 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


[74] [75]

K.L. Richter, R. Mattes, Inorg. Chem. 30 (1991) 4367–4369. E. Shannon, W. Weaver, W., The Mathematical Theory of Communication. University of Illinois Press, Urbana, IL, 1949. [76] D. Bonchev, D.H. Rouvray, eds. Complexity in Chemistry, Biology, and Ecology. Springer New York, 2005. [77] S.V. Krivovichev, Acta Crystallogr. A68 (2012) 393-396. [78] S.V. Krivovichev, Angew. Chem. Int. Ed. 53 (2014) 654-661. [79] A. Aliev, V.M. Kovrugin, M. Colmont, C. Terryn, M. Huve, O.I. Siidra, S.V. Krivovichev, O. Mentre, Cryst. Growth Des. 14 (2014) 3026-3034. [80] G. Ferraris, E. Makovicky, S. Merlino, Crystallography of Modular Materials. IUCr/Oxford University Press, Oxford, 2008.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Table 1. Crystallographic Data for the compounds I, II, III, and IV. Compounds

I β–(V5+2O3) (SeO3)2

Preparation

CVT

II Pb2(V4+O) (SeO3)3 hydrothermal (hydrazine)

III β–Pb4(V5+3O8)2 (SeO3)3(H2O)

IV α–Pb4(V5+3O8)2 (SeO3)3(H2O)

hydrothermal

hydrothermal

monoclinic

triclinic

monoclinic

Crystal data Crystal system

monoclinic

Space group

P21/c

P21/n

P–1

P21

a (Å)

7.1812(3)

5.1938(3)

7.1425(2)

7.1374(2)

b (Å)

7.0753(2)

16.1141(9)

7.1933(2)

21.2920(5)

c (Å)

14.0486(5)

11.2533(6)

21.5261(7)

7.1990(2)

90.0190(10) β (°)

101.5462(15)

90.527(2)

98.1800(10)

94.8499(11)

Volume (Å3)

699.35(4)

941.79(9)

1091.12(6)

1090.11(5)

Z

4

4

2

2

Mr (g mol )

403.80

862.20

1789.30

1789.30

Dcalc (g/cm3)

3.835

6.081

5.446

5.451

13.105

48.272

38.305

38.340

94.5980(10)

–1

µ (mm–1) 3

Crystal size (mm )

0.21×0.12×0.10 0.20×0.11×0.11 0.22×0.18×0.11 0.23×0.19×0.17

Crystal colour

red

brown

yellow

orange

MoKα, 0.71073 Å 1.9 − 30.5

Bruker APEX-II X8 MoKα, 0.71073 Å 2.8 − 31.0

Data collection Equipment Radiation θ range

Bruker APEX-II DUO MoKα, MoKα, 0.71073 Å 0.71073 Å 2.9 − 30.4 3.1 − 31.5

Total ref.

7488

9381

21653

18681

Unique ref. (Rint)

2126 (0.0252)

3062 (0.0305)

6579 (0.0272)

6658 (0.0330)

Unique ref. F>4σF

1835

2611

5971

6087

Structure refinement R1[F>4σF]

0.0232

0.0236

0.0260

0.0293

wR2[F>4σF]

0.0503

0.0411

0.0535

0.0529

R1 all

0.0298

0.0322

0.0302

0.0339

0.0429 1.059 1.400, –1.339

0.0549 1.042 5.057, –2.958

0.0538 1.002 3.404, –2.533

wR2 all 0.0527 GOF 1.065 ∆ρmax/∆ρmin (e Å–3) 1.034, –0.494


Page 18 of 27

Page 19 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table 2. Stretching vibrations observed in I, II, III, and IV. ν(Se–O), cm–1

ν(V–O), cm–1

ν(V–O–V), cm–1

β–(V2O3)(SeO3)2

985, 871

797, 766, 672–649

Pb2(VO)(SeO3)3

913, 873

797, 647

615–588, 533, 452–419 530, 484, 476, 432

ν(H–O–H), cm–1

* ethanol ν(C–H), cm–1 1022 2987, 1411

2907,

953, 934, 820, 765, 518–472, 443 1622 895, 856 671–632 770, 934, 895, 815, β–Pb4(V3O8)2(SeO3)3(H2O) 520–448, 419 1625 2956, 2853 858 673–627 * the presence of the bands of the ethanol molecules in the IR spectra is a consequence of the use of ethanol for cleaning of the ATR accessory of the spectrometer between the measurements of the samples of different phases α–Pb4(V3O8)2(SeO3)3(H2O)

Table 3. Structural data for the known compounds with general formula (V2O3)(TOx) (T = Se4+/6+, Te4+, S6+; x = 3, 4). Chemical formula

Space group

a (Å); α (°)

b (Å); β (°)

c (Å); γ (°)

V (Å3)

Basic structural units

Role of TOx

Fig.

Ref.

Linkage into 3D

6a

1

Linkage into 2D

6b

*

6c

2, 3

6d

4

6e

4, 5, 6

16–

α– (V2O3)(SeO3)2

P21/n

8.055; 90.0

10.356; 102.79

8.430; 90.0

685.8

β– (V2O3)(SeO3)2

P21/c

7.181; 90.0

7.075; 101.5

14.049; 90.0

699.4

28.010; 6.794; 7.218; 1373.6 90.0 90.0 90.0 15.383; 5.541; 9.716; C2/c 768.51 (V2O3)(SeO4)2 90.0 111.9 90.0 9.472; 8.913; 9.891; (V2O3)(SO4)2 P21/a 808.2 90.0 104.6 90.0 * – this work, 1 – [56], 2 – [58], 3 – [57], 4 – [3], 5 – [53], 6 – [59]. (V2O3)(TeO3)2

Fdd2

{(V4O18)} square tetramers of vanadate octahedra {(V4O12)}4– cruciform tetramers of square pyramids and octahedra [VO4]8– chains of edgeshared octahedra {(V2O11)}17– dimers of corner-shared octahedra {(V2O11)}17– dimers of corner-shared octahedra


Linkage into 3D Linkage into 3D Linkage into 3D


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Fig. 1. General scheme of the CVT method and optical microscope image of the deposition zone of the tube after the CVT synthesis.

Fig. 2. Experimental solid phase space of the PbCl2−V2O5−SeO2−H2O (a) and PbO−V2O5−SeO2−H2O (b) systems at 473 K with the pH zones shown in the background by gray colors. The compositions of various phases synthesized in each experimental point are shown by circles of different colors. * – this phase reported in [5] was not reproduced in our experiments performed at lower temperature (473K vs 503K in [5]) and less time thermal treatment (2 days vs 4 days in [5]).


Page 20 of 27

Page 21 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Fig. 3. Optical microscope and SEM images of the crystals of β–(V2O3)(SeO3)2 (I) – (a,e), Pb2(VO)(SeO3)3 (II) – (b,f), β–Pb4(V3O8)2(SeO3)3(H2O) (III) – (c, g), and α– Pb4(V3O8)2(SeO3)3(H2O) (IV) – (d, h).

Fig. 4. FTIR-ATR spectra for β–(V2O3)(SeO3)2 (I) – (a), Pb2(VO)(SeO3)3 (II) – (b), α– Pb4(V3O8)2(SeO3)3(H2O) (IV) – (c), and β–Pb4(V3O8)2(SeO3)3(H2O) (III) – (d).



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Fig. 5. crystal structure of β–(V2O3)(SeO3)2 : tetrameric {(V4O12)(SeO3)2}8– unit – (a); Projections along the(100) and (010) axes (b) and (c); view of the crystal structure of α–(V2O3)(SeO3)2 – (d); its vanadate selenite chain – (e), and tetrameric {(V4O18)}16– ) axesunit – (f). Legend: polyhedral representation: V5+O6 octahedra, V5+O5 square pyramids, Se4+O3 triangular pyramids and lone pairs are blue, green, orange and grey, respectively; graph representation: V5+ are black circles, Se4+ are white circles, single and double links indicate sharing of corners and edges between two polyhedra, respectively.


Page 22 of 27

Page 23 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Fig. 6. Vanadate selenite layer (a), and its black-and-white graph (b) in the crystal structure of β– (V2O3)(SeO3)2.

Fig. 7. Structural units in the crystal structures of the series of isoformular phases (V2O3)(TOx) (T = Se4+/6+, Te4+, S6+; x = 3, 4).



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Fig. 8. General projection of the crystal structure of Pb2(VO)(SeO3)3 – (a), vanadate selenite chain – (b), and its black-and-white graph – (c). Legend as in Fig. 5.

Fig. 9. Coordination pf Pb2+ cations in the crystal structures of Pb2(VO)(SeO3)3 – (a,b) and β– Pb4(V3O8)2(SeO3)3(H2O) – (c–f). Interatomic distances are given in Å.


Page 24 of 27

Page 25 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Fig. 10. Projections of the crystal structures of α–Pb4(V3O8)2(SeO3)3(H2O) – (a), and β– Pb4(V3O8)2(SeO3)3(H2O)– (b). Hydrogen bonding is shown by yellow.

Fig. 11. Structural units in in the crystal structure of β–Pb4(V3O8)2(SeO3)3(H2O). Coordination environment of V5+ and Se4+ cations – (a), (c), and (e); [V4O14]8– chains – (b); [V6O20]10– chains – (d); l [(V6O16)(SeO3)3]8– ribbons – (f).



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Fig. 12. Mode of packing of the vanadate selenite ribbons in the crystal structures of α– Pb4(V3O8)2(SeO3)3(H2O) – (a) and β–Pb4(V3O8)2(SeO3)3(H2O) – (b).


Page 26 of 27

Page 27 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


For Table of Contents Use Only

Title : Exploration of vanadate selenites solid phase space, crystal structures and polymorphism Authors : Vadim M. Kovrugin, Marie Colmont, Oleg I. Siidra, Sergey V. Krivovichev, Olivier Mentré

TOC graphic.

Synopsis

A systematic method for the crystallization in the Pb-V-Se-O system using both hydrothermal and CVT was used. Besides the determination of stable predominant phases in the diagram such as Pb2(VO3)(SeO3)2Cl, it enables the crystallization of three novel vanadate selenites, β–(V5+2O3)(SeO3)2 (I), Pb2(V4+O)(SeO3)3 (II), and β–Pb4(V5+3O8)2(SeO3)3(H2O) (III), depending on the method, pH and potential of the solution.


Exploration of Vanadate Selenites Solid Phase Space, Crystal

Recommend Documents