TY - JOUR

T1 - Uranyl nitrates

T2 - By-products of the synthetic experiments or key indicators of the reaction progress?

AU - Gurzhiy, Vladislav V.

AU - Tyumentseva, Olga S.

AU - Kornyakov, Ilya V.

N1 - Funding Information: Funding: This research was funded by the Russian Science Foundation (grant 18-17-00018). Publisher Copyright: © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/12/10

Y1 - 2020/12/10

N2 - Six novel uranyl nitrate compounds K3[(UO2)(NO3)Cl3](NO3) (1, 2), α-Cs2[(UO2)(NO3)Cl3] (3), [(UO2)(NO3)2(H2O)2][(CH3NH3)2(NO3)2] (4), Cs2[(UO2)(NO3)4] (5), and [(UO2)2(OH)2(NO3)2(H2O)3](H2O) (6) have been prepared from aqueous solutions. Their structures were analyzed using single-crystal X-ray diffraction technique. Structural studies have shown that the crystals of 1 and 2 are isotypic but differ in the distortion at the counter ion’s sites. The crystal of 3 is a low-temperature polymorph modification of the recently studied compound. The crystal structure of 4 is composed of uranyl-dinitrate-dihydrate and methylamine-nitrate electroneutral complexes linked through the system of H-bonds. The crystal structure of 5 is based on the finite [(UO2)(NO3)4]2– clusters that are arranged in pseudo-chained complexes extended along [100] and are arranged according to a hexagonal packing or rods. The crystal of 6 is also a novel polymorph modification of previously studied compound, the structure of which is based on the very rare topological type of the finite clusters. Nowadays, uranyl nitrate finite clusters of nine various topological types are known. We give herein a short review of their topological features and relationships. Crystallization of uranyl nitrates usually occurs when all other competitive anions in the system have already formed crystalline phases, or the reaction of reagents have slowed down or even stopped. Thus it is suggested that crystallization of uranyl nitrates can be used as a key indicator of the reaction progress, which points to the necessity of the initial concentrations of reagents correction, or to the replacement of reagents and adjustment of the thermodynamic (P,T) parameters of the synthesis.

AB - Six novel uranyl nitrate compounds K3[(UO2)(NO3)Cl3](NO3) (1, 2), α-Cs2[(UO2)(NO3)Cl3] (3), [(UO2)(NO3)2(H2O)2][(CH3NH3)2(NO3)2] (4), Cs2[(UO2)(NO3)4] (5), and [(UO2)2(OH)2(NO3)2(H2O)3](H2O) (6) have been prepared from aqueous solutions. Their structures were analyzed using single-crystal X-ray diffraction technique. Structural studies have shown that the crystals of 1 and 2 are isotypic but differ in the distortion at the counter ion’s sites. The crystal of 3 is a low-temperature polymorph modification of the recently studied compound. The crystal structure of 4 is composed of uranyl-dinitrate-dihydrate and methylamine-nitrate electroneutral complexes linked through the system of H-bonds. The crystal structure of 5 is based on the finite [(UO2)(NO3)4]2– clusters that are arranged in pseudo-chained complexes extended along [100] and are arranged according to a hexagonal packing or rods. The crystal of 6 is also a novel polymorph modification of previously studied compound, the structure of which is based on the very rare topological type of the finite clusters. Nowadays, uranyl nitrate finite clusters of nine various topological types are known. We give herein a short review of their topological features and relationships. Crystallization of uranyl nitrates usually occurs when all other competitive anions in the system have already formed crystalline phases, or the reaction of reagents have slowed down or even stopped. Thus it is suggested that crystallization of uranyl nitrates can be used as a key indicator of the reaction progress, which points to the necessity of the initial concentrations of reagents correction, or to the replacement of reagents and adjustment of the thermodynamic (P,T) parameters of the synthesis.

KW - Chloride

KW - Crystal structure

KW - Nitrate

KW - Topology

KW - Uranyl

KW - X-ray diffraction

UR - http://www.scopus.com/inward/record.url?scp=85098509649&partnerID=8YFLogxK

U2 - 10.3390/cryst10121122

DO - 10.3390/cryst10121122

M3 - Article

AN - SCOPUS:85098509649

VL - 10

SP - 1

EP - 15

JO - Crystals

JF - Crystals

SN - 2073-4352

IS - 12

M1 - 1122

ER -