scholarly journals Kinetic and Thermodynamic Control in Rare Earth Cyamelurates Synthesis

2021 ◽  
Author(s):  
Albina S. Isbjakowa ◽  
Vladimir V. Chernyshev ◽  
Victor A. Tafeenko ◽  
Leonid A Aslanov
Keyword(s):  
Rare Earth ◽  
Coordination Number ◽  
Room Temperature ◽  
Synthesis Temperature ◽  
Thermodynamic Control ◽  
Temperature Synthesis ◽  
Complex Molecules ◽  
Bridging Ligand ◽  
Structural Types ◽  
Polymeric Chains

Abstract If various compounds exist in the metal cation – C6N7O33– – H2O system, the synthesis temperature can affect the isolation of a particular product. Low temperatures favor the release of metastable kinetic products, and high temperatures, on the contrary, of thermodynamic ones. It is found that several structural types exist in the row of rare-earth cyamelurates. Room temperature synthesis leads to the formation of [Ln(H2O)7C6N7O3] (Ln=Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er), an increase in temperature yields thermodynamically more stable [Ln(H2O)4C6N7O3]n·nH2O (Ln=Y, Ho, Er, Tm, Yb, Lu) and [Ln(H2O)5C6N7O3]n (Ln = Pr, Nd). The change in the synthesis temperature did not affect the structures of Sm, Eu, Gd, Tb, Dy cyamelurates, as well as the structure of lanthanum cyamelurate [La(H2O)6C6N7O3]·H2O.In synthesized at increased temperature [Ln(H2O)4C6N7O3]n·nH2O and [Ln(H2O)5C6N7O3]n cyamelurates polymeric chains exist due to the fact that the cyamelurate anion acts as a bridging ligand. Kinetically trapped Y, Pr, Nd, Ho, Er cyamelurates, in contrast, consist of individual complex molecules [Ln(H2O)7C6N7O3]. Probably, steric difficulties caused a decrease in the coordination number of Y, Ho, Er from 9 to 8 in the thermodynamic product. The coordination number of Pr and Nd remains equal to 9 in both types of compounds.

scholarly journals Nanometric solid solutions of the fluorite and perovskite type crystal structures: Synthesis and properties

2012 ◽  
Vol 6 (3) ◽  
pp. 123-131 ◽  
Author(s):  
Snezana Boskovic ◽  
Slavica Zec ◽  
Branko Matovic ◽  
Zorana Dohcevic-Mitrovic ◽  
Zoran Popovic ◽  
...  
Keyword(s):  
Rare Earth ◽  
Crystal Structures ◽  
Solid Solutions ◽  
Room Temperature ◽  
Short Review ◽  
Temperature Synthesis ◽  
Innovative Methods ◽  
Different Types ◽  
Perovskite Type ◽  
Type Crystal

In this paper a short review of our results on the synthesis of nanosized CeO2, CaMnO3 and BaCeO3 solid solutions are presented. The nanopowders were prepared by two innovative methods: self propagating room temperature synthesis (SPRT) and modified glycine/nitrate procedure (MGNP). Different types of solid solutions with rare earth dopants in concentrations ranging from 0-0.25 mol% were synthesized. The reactions forming solid solutions were studied. In addition, the characteristics of prepared nanopowders, phenomena during sintering and the properties of sintered samples are discussed.

Structural Systematics of Rare Earth Complexes. XV Tris(2,2′:6′,2″-terpyridine)lanthanoid(III) Tris(perchlorate) Complexes

1999 ◽  
Vol 52 (6) ◽  
pp. 519 ◽  
Author(s):  
Lioubov I. Semenova ◽  
Alexander N. Sobolev ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Coordination Number ◽  
Room Temperature ◽  
Structural Type ◽  
Rare Earth Complexes ◽  
X Ray ◽  
Structure Determinations

Room-temperature single-crystal X-ray structure determinations of the 1 : 3 adducts of the trivalent lanthanoid perchlorates with 2,2′:6′,2″-terpyridine (‘tpy’) as crystallized from acetonitrile are recorded. The Ln = La complex is the only one of its structural type, being modelled as La(ClO4)3/tpy/MeCN/H2O (1 : 3 : 2 :2/3), trigonal P 3c1, Z = 6, a 13·063(7), c 53·04(4) Å, recorded on an interim basis, with conventional R on |F| 0·081 for No 2889 ‘observed’ (I >3σ(I)) reflections. For Ln = Ce, (Pr, Sm,) Eu and, by presumption, other intermediate members, a monosolvate is found, monoclinic P 21/n, a ≈ 9·3, b ≈ 21·1, c ≈ 24·7 Å, β ≈ 91°, Z = 4, R being 0·045, (0·060, 0·049,) 0·047 for No 4420, (4199, 3931,) 3713. The Ln = Eu adduct has also been obtained unsolvated in a form representative of Ln = Eu, Lu and, by presumption, intermediate members, as well as Y, which is monoclinic C 2/c, Z = 4, R being 0·051, 0·044, 0·061 for No 4386, 4407, 3713. All monoclinic systems are of the form [Ln(tpy)3] (ClO4)3(.S), Ln being nine-coordinate, and in the case of the C 2/c phase lying on a crystallographic 2 axis. The Ln = La adduct was modelled with three independent cations, all with crystallographic 3 symmetry, two with their coordination number augmented by the approach of solvent along the 3 axis.

Reaction of Ce1-xRexO2-δ Nanopowders Synthesis

2006 ◽  
Vol 518 ◽  
pp. 95-100 ◽  
Author(s):  
Snezana Bošković ◽  
D. Djurović ◽  
B. Matović ◽  
M. Čančarević ◽  
Z. Dohčević-Mitrović ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solid Oxide Fuel Cells ◽  
Room Temperature ◽  
Solid Oxide ◽  
Powder Synthesis ◽  
Temperature Synthesis ◽  
New Generation ◽  
Nanostructured Ceramics ◽  
Rare Earth Doped ◽  
Very High

One of the methods for powder synthesis that is both cost and time effective is the selfpropagating room temperature synthesis. We applied this method to synthesize rare earth doped ceria nanopowders. Since they exhibit very high ionic conductivity at intermediate temperatures these compositions are attractive for a new generation of nanostructured ceramics applicable in solid oxide fuel cells as electrolytes. In this paper we paid our attention to the reaction based on methathetical pathway, whereby solid solution nanopowders of rare earth elements with ceria were obtained at room temperature. Compositions of Ce1-xRexO2-δ (Re = Y , Nd) were synthesized with x ranging from 0 to 0.20. The reaction course is discussed and the properties of the obtained powders are presented.

Room-temperature synthesis, growth mechanisms and opto-electronic properties of organic–inorganic halide perovskite CH3NH3PbX3 (X = I, Br, and Cl) single crystals

CrystEngComm ◽  
2021 ◽  
Author(s):  
Maryam Bari ◽  
Hua Wu ◽  
Alexei A. Bokov ◽  
Rana Faryad Ali ◽  
Hamel N. Tailor ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Single Crystals ◽  
Room Temperature ◽  
Solubility Curve ◽  
Inverse Temperature ◽  
Growth Mechanisms ◽  
Temperature Synthesis ◽  
Room Temperature Synthesis ◽  
Halide Perovskite ◽  
Temperature Crystallization

Growth of MAPbX3 (X = I, Br, and Cl) single crystals by room temperature crystallization (RTC) method, and the crystallization pathway illustrated by the solubility curve of MAPbCl3 in DMSO, compared with inverse temperature crystallization (ITC) method.

scholarly journals Self-assembly induced luminescence of Eu3+-complexes and application in bioimaging

2021 ◽  
Author(s):  
Ping-Ru Su ◽  
Tao Wang ◽  
Pan-Pan Zhou ◽  
Xiao-Xi Yang ◽  
Xiao-Xia Feng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Rare Earth ◽  
Luminescence Intensity ◽  
Self Assembly ◽  
Room Temperature ◽  
Molecular Motion ◽  
Proof Of Concept ◽  
Room Temperature Phosphorescence ◽  
New Strategy ◽  
Size Controlled

Abstract Design and engineering of highly efficient emitting materials with assembly-induced luminescence, such as room temperature phosphorescence (RTP) and aggregation-induced emission (AIE), have stimulated extensive efforts. Here, we propose a new strategy to obtain size-controlled Eu3+-complex nanoparticles (Eu-NPs) with self-assembly induced luminescence (SAIL) characteristics without encapsulation or hybridization. Compared with previous RTP or AIE materials, the SAIL phenomena of increased luminescence intensity and lifetime in aqueous solution for the proposed Eu-NPs are due to the combined effect of self-assembly in confining the molecular motion and shielding the water quenching. As a proof of concept, we also show that this system can be further applied in bioimaging, temperature measurement and HClO sensing. The SAIL activity of the rare-earth (RE) system proposed here offers a further step forward on the roadmap for the development of RE light conversion systems and their integration in bioimaging and therapy applications.

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