Dehydration-driven evolution of topological complexity in ethylamonium uranyl selenates

Gurzhiy, Vladislav V.; Krivovichev, Sergey V.; Тананаев, И. Г.

doi:10.1016/j.jssc.2017.01.005

Cited by 16 publications

(13 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first compound was obtained from the reaction of UO 2 (NO 3 ) 2 ·6H 2 O with selenic acid (H 2 SeO 4 ) in aqueous medium for 1 year, which could be explained by the reduction of Se(VI) to Se(IV) in the solution during the experiment. Moreover, as it was recently shown, the hydronium ions usually enter the structure at the very latest crystallization stages, when there are no more other cations in the solution [52,59,60]. The Na-bearing compound was obtained in the presence of sodium oxalate, which probably could be regarded as a catalyst of the uranyl selenite crystallization process.…”

Section: Synthetic Uranyl Compounds With Selenite Ionsmentioning

confidence: 85%

“…The graph is a vertex-sharing infinite chain of four-membered rings with additional one-connected selenite group to each Ur. This topology is quite rare and has been observed in the structures of two synthetic uranyl chromates Na 4 5 [69], and one uranyl selenate (C 2 H 8 N) 3 [(UO 2 )(SeO 4 ) 2 (HSeO 4 )] [52]. U 6+ atoms are arranged in the centers of pentagonal bipyramids, so that four equatorial vertices of which are shared with two-connected selenite groups (as in previous type), and the fifth vertex that was occupied by H 2 O molecule, now is replaced by another one-connected [SeO 3 ] 2− pyramid.…”

Section: Topological Analysismentioning

confidence: 99%

See 1 more Smart Citation

Crystal Chemistry and Structural Complexity of Natural and Synthetic Uranyl Selenites

et al. 2019

Self Cite

View full text Add to dashboard Cite

Comparison of the natural and synthetic phases allows an overview to be made and even an understanding of the crystal growth processes and mechanisms of the particular crystal structure formation. Thus, in this work, we review the crystal chemistry of the family of uranyl selenite compounds, paying special attention to the pathways of synthesis and topological analysis of the known crystal structures. Comparison of the isotypic natural and synthetic uranyl-bearing compounds suggests that uranyl selenite mineral formation requires heating, which most likely can be attributed to the radioactive decay. Structural complexity studies revealed that the majority of synthetic compounds have the topological symmetry of uranyl selenite building blocks equal to the structural symmetry, which means that the highest symmetry of uranyl complexes is preserved regardless of the interstitial filling of the structures. Whereas the real symmetry of U-Se complexes in the structures of minerals is lower than their topological symmetry, which means that interstitial cations and H 2 O molecules significantly affect the structural architecture of natural compounds. At the same time, structural complexity parameters for the whole structure are usually higher for the minerals than those for the synthetic compounds of a similar or close organization, which probably indicates the preferred existence of such natural-born architectures. In addition, the reexamination of the crystal structures of two uranyl selenite minerals guilleminite and demesmaekerite is reported. As a result of the single crystal X-ray diffraction analysis of demesmaekerite, Pb 2 Cu 5 [(UO 2 ) 2 (SeO 3 ) 6 (OH) 6 ](H 2 O) 2 , the H atoms positions belonging to the interstitial H 2 O molecules were assigned. The refinement of the guilleminite crystal structure allowed the determination of an additional site arranged within the void of the interlayer space and occupied by an H 2 O molecule, which suggests the formula of guilleminite to be written as Ba 3 . occurrence is limited to just a few localities. First, these are Musonoi and Shinkolobwe mines in DR Congo [6], two of the minerals were only found in the Repete mine (San Juan County, Utah, USA) [5], and a few more occurrences in Europe could be mentioned (small uranium deposit Zálesí in the Czech Republic, Liauzun in France, and La Creusaz U prospect in Switzerland) [8]. Nevertheless, apart from mineralogy, uranyl selenites are of great interest from the geochemical and radiochemical points of view. It is known that fission products contain 53 g per ton [9] of long-lived 79 Se isotope with a half-life of 1.1 × 10 6 years [10] after three years of nuclear fuel irradiation in the reactor. Thus, an understanding of the processes of mineral formation in nature and their synthetic analogs in laboratories can help in the processing of nuclear wastes. Crystal chemical and structural investigations are key points in such a material's scientific studies due to the essential knowledge of how the variation in the chemical composi...

show abstract

Section: Synthetic Uranyl Compounds With Selenite Ionsmentioning

confidence: 85%

Section: Topological Analysismentioning

confidence: 99%

Crystal Chemistry and Structural Complexity of Natural and Synthetic Uranyl Selenites

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…This row could be continued by the further doubling of the cluster in K 4 (UO 2 (SO 4 ) 3 ) [44] to get the quadruple 0D unit in the structure of ottohahnite (Figure 4). Further increase of the cluster size led to the arrangement of the infinite chains in the structure of 3, which in turn, during the dehydration process [34], would transform into the layer in the structure of 4. The absence of the structures based on the 0D structural units in our experiment might come from the requirements for longer storage at elevated, but not high, temperatures, and higher concentrations of Cs + cations and [SO 4 ] 2− oxyanions in the initial solution.…”

Section: Discussionmentioning

confidence: 99%

“…Second, the structural complexity (SI) of the units was analyzed, taking into account its real symmetry. The next contribution to information came from the stacking (LS) The general trend in evolution of crystallization was recently summarized as follows [33][34][35][36]: complexities of structures formed on the latter stages of crystallization are higher than those for the phases growing on the primary stages, wherein very complex structures may form as transitional architectures prior or between phases with relatively small amounts of structural information.…”

Section: Structural Complexitymentioning

confidence: 99%

Crystallographic Insights into Uranyl Sulfate Minerals Formation: Synthesis and Crystal Structures of Three Novel Cesium Uranyl Sulfates

et al. 2019

Self Cite

View full text Add to dashboard Cite

An alteration of the uranyl oxide hydroxy-hydrate mineral schoepite [(UO2)8O2(OH)12](H2O)12 at mild hydrothermal conditions was studied. As the result, four different crystalline phases Cs[(UO2)(SO4)(OH)](H2O)0.25 (1), Cs3[(UO2)4(SO4)2O3(OH)](H2O)3 (2), Cs6[(UO2)2(SO4)5](H2O)3 (3), and Cs2[(UO2)(SO4)2] (4) were obtained, including three novel compounds. The obtained Cs uranyl sulfate compounds 1, 3, and 4 were analyzed using single-crystal XRD, EDX, as well as topological analysis and information-based structural complexity measures. The crystal structure of 3 was based on the 1D complex, the topology of which was unprecedented for the structural chemistry of inorganic oxysalts. Crystal chemical analysis performed herein suggested that the majority of the uranyl sulfates minerals were grown from heated solutions, and the temperature range could be assumed from the manner of interpolyhedral linkage. The presence of edge-sharing uranyl bipyramids most likely pointed to the temperatures of higher than 100 °C. The linkage of sulfate tetrahedra with uranyl polyhedra through the common edges involved elevated temperatures but of lower values (~70–100 °C). Complexity parameters of the synthetic compounds were generally lower than that of uranyl sulfate minerals, whose structures were based on the complexes with the same or genetically similar topologies. The topological complexity of the uranyl sulfate structural units contributed the major portion to the overall complexity of the synthesized compounds, while the complexity of the respective minerals was largely governed by the interstitial structure and H-bonding system.

show abstract

“…In order to evaluate the influence of various crystal-chemical factors (such as dimensionality of the uranium-bearing units and their hydration state) on the structure and symmetry of uranyl sulfate complexes and on the structural architecture of minerals in general, the structural and topological complexity was studied in terms of the information-based approach developed by Krivovichev (2012Krivovichev ( , 2013Krivovichev ( , 2014 and recently used by Cempírek et al (2016), Gurzhiy et al (2016Gurzhiy et al ( , 2017Gurzhiy et al ( , 2018a, Krivovichev et al (2016Krivovichev et al ( , 2017, Majzlan et al (2018) and Plá šil (2018a,b). The structural complexity is quantitatively estimated as a Shannon information content per atom (I G ) and per unit cell (I G,total ).…”

Section: Complexity Calculationsmentioning

confidence: 99%

Structural complexity of natural uranyl sulfates

Gurzhiy

Plášil

2019

Acta Crystallogr Sect B

Self Cite

View full text Add to dashboard Cite

Uranyl sulfates, including those occurring in Nature (∼40 known members), possess particularly interesting structures. They exhibit a great dimensional and topological diversity of structures: from those based upon clusters of polyhedra to layered structures. There is also a great variability in the type of linkages between U and S polyhedra. From the point of view of complexity of those structures (measured as the amount of Shannon information per unit cell), most of the natural uranyl sulfates are intermediate (300–500 bits per cell) to complex (500–1000 bits per cell) with some exceptions, which can be considered as very complex structures (>1000 bits per cell). These exceptions are minerals alwilkinsite‐(Y) (1685.95 bits per cell), sejkoraite‐(Y) (1859.72 bits per cell), and natrozippeite (2528.63 bits per cell). The complexity of these structures is due to an extensive hydrogen bonding network which is crucial for the stability of these mineral structures. The hydrogen bonds help to propagate the charge from the highly charged interlayer cations (such as Y3+) or to link a high number of interlayer sites (i.e. five independent Na sites in the monoclinic natrozippeite) occupied by monovalent cations (Na+). The concept of informational ladder diagrams was applied to the structures of uranyl sulfates in order to quantify the particular contributions to the overall informational complexity and identifying the most contributing sources (topology, real symmetry, interlayer bonding).

show abstract

Dehydration-driven evolution of topological complexity in ethylamonium uranyl selenates

Cited by 16 publications

References 25 publications

Crystal Chemistry and Structural Complexity of Natural and Synthetic Uranyl Selenites

Crystal Chemistry and Structural Complexity of Natural and Synthetic Uranyl Selenites

Crystallographic Insights into Uranyl Sulfate Minerals Formation: Synthesis and Crystal Structures of Three Novel Cesium Uranyl Sulfates

Structural complexity of natural uranyl sulfates

Contact Info

Product

Resources

About