Thallium Cations Research Articles

Synthesis and Characterization of Low-Dimensional Quaternary Sulfides of Thallium, Tl2Cu2GeS4, Tl2Ag2GeS4, and Tl2Ag2SnS4.

Three new low-dimensional quaternary sulfides, namely, Tl2Cu2GeS4(1), Tl2Ag2GeS4(2), and Tl2Ag2SnS4(3) were synthesized by solid-state reactions and characterized by single-crystal X-ray diffraction, spectroscopic, thermal, and photocatalytic studies. The compounds 1, 2, and 3, respectively, have centrosymmetric layered, noncentrosymmetric layered, and noncentrosymmetric one-dimensional structures, in which Cu+, Ge4+, and Sn4+ ions have tetrahedral coordination and Ag+ ion has linear, trigonal planar and tetrahedral coordinations. The monovalent thallium cations have TlS8 dodecahedral coordination and TlS7 and TlS6 coordination polyhedra of irregular shape. The compounds 1, 2, and 3 are semiconductors with the respective energy band gap values of 1.68, 2.02, and 1.90 eV. Compared to compounds 1 and 2, compound 3 has a higher efficiency value of 22.9% for the photodegradation of aqueous solution of methylene blue. Band structures and projected density of states of all three compounds were computed using density functional theory, and these results are in good agreement with experiments.

Reaction of Tl+ with corannulene: Experimental and theoretical study

The interaction of Tl+ cation with corannulene was investigated by using electrospray ionization mass spectrometry (ESI-MS). It was found that the thallium cation Tl+ forms with corannulene (C20H10) two cationic complexes [Tl(C20H10)]+ and [Tl(C20H10)2]+. Quantum chemical calculations proceed by density functional theory with two different functionals (B3LYP and M06-D3) provided the most probable structures of these complexes. In the energetically most favored conformation of [Tl(C20H10)]+ complex, the Tl+ cation lies on the apex of pyramid which base is formed by the central pentagon of the convexly oriented corannulene molecule. In the [Tl(C20H10)2]+ complex the “central” cation Tl+ is situated between two molecules of the corannulene ligand. Both ligand molecules are convex to the Tl+ cation. The interaction energies, E(int), of the considered cation-π complexes [Tl(C20H10)]+ and [Tl(C20H10)2]+ were calculated to be −121.75 and −176.98 kJ/mol, respectively.

A Water-Soluble Cryptophane Decorated with Aromatic Amine Groups Shows High Affinity for Cesium and Thallium(I).

An anti-cryptophane decorated with three aromatic amine and three phenol groups shows a high affinity for the cesium and thallium cations in LiOH/H2O (0.1 M). The formation of the complexes was studied by 133Cs NMR and by 205Tl NMR spectroscopy at different temperatures. Characteristic signals for caged cesium and thallium were observed at a high field with respect to the signals of the free cations present in the bulk. Isothermal titration calorimetric experiments performed in LiOH/H2O (0.1 M) and NaOH/KCl buffer (pH = 13) allowed us to determine the parameter of complexation and to ascertain the high affinity of this cryptophane for cesium and thallium. A comparison with other cryptophanes that bind these two cations shows that the introduction of nitrogen atoms into the cryptophane backbone has an effect on the binding properties. The affinity for cesium and thallium(I) ions is in the following order of substitution: OH > NH2 > OCH2COOH. This study paves the way to the design of new efficient host molecules for the extraction of these two cations in aqueous solution.

Impact of the Syn/Anti Relative Configuration of Cryptophane-222 on the Binding Affinity of Cesium and Thallium.

We report in this article the synthesis, the X-ray crystal structure of compound syn-2, and its binding properties with cesium and thallium in aqueous solution under basic conditions. Compound syn-2 is the diastereomeric compound of anti-1 that shows very high affinity for cesium and thallium in aqueous solution under the same conditions. Despite the close structural similarities that exist between the syn-2 and anti-1 compounds, they show large discrepancy in their ability to bind cesium and thallium cations in the same conditions. Indeed, the syn-2 derivative has a lower affinity for these two cationic species and the binding constants are several orders of magnitude lower than those found for its congener. The large differences in affinity observed with these two compounds can be explained by the relative position of the six hydroxyl groups to each other.

Effect of Introducing Thallium in Microporous Vanado-molybdate with Orthorhombic or Trigonal Structures and Catalytic Properties

Thallium-containing mixed vanadium and molybdenum oxides have been synthesized using a microwave-assisted hydrothermal method. The pH, the nature of the metal precursors, and the use of a structuring agent were shown to be key parameters of the synthesis; depending upon these parameters, trigonal (Tri) or orthorhombic (M1) structures were obtained. Both structures have been characterized by X-ray diffraction (XRD) and scanning and transmission electron microscopies (SEM and TEM, respectively). The orthorhombic phase has lattice parameters of a = 2.108 nm, b = 2.656 nm, c = 0.3997 nm and space group Pba2, and the trigonal phase, lattice parameters of a = 2.143 nm, c = 0.4004 nm and space group P3. In the orthorhombic phase, both hexagonal and heptagonal channels are partially but consistently occupied by thallium cations. The trigonal phase also exhibited both hexagonal and heptagonal channels; hexagonal channels were occupied by thallium cations, whereas the heptagonal channels appeared almost empty. The catalytic properties of the solids have been studied for the oxidative dehydrogenation of ethane and the oxidation of propene to acrylic acid. The orthorhombic phase was inactive; the trigonal phase, while not very active, had a high selectivity to ethylene. Although the occupancy rate of the heptagonal sites is probably low in the later phase, it strongly attenuates its activity.

Reaction of the thallium(I) cation with [2.2]paracyclophane: Experimental and theoretical study

Electrospray ionization mass spectrometry was used to investigate the cation-π interaction of Tl+ cation with [2.2]paracyclophane. It was found that 1:1 cationic complex species is formed in the gas phase. Further, applying quantum mechanical calculations in the frame of the density functional theory, applying B3LYP functional with Def2TZVP basis set, the most probable structure of the proved [2.2]paracyclophane – Tl+ complex was derived. In the resulting complex, the cation Tl+ is bounded to six carbon atoms of one benzene ring of [2.2]paracyclophane ligand via cation-π interaction. The interaction energy, E(int), of this cation-π complex was calculated to be −133.59 kJ/mol, which is consistent with the formation of the considered Tl+ – [2.2]paracyclophane complex species.

Lead-Free Cs2BB′X6 (B: Ag/Au/Cu, B′: Bi/Sb/Tl, and X: Br/Cl/I) Double Perovskites and Their Potential in Energy Conversion Applications

A mere decade-long research focused on perovskites for photovoltaics (PVs) has unearthed their exciting promise. However, as an alternative to the inaugural class of single perovskites, which suffer from instability and toxicity, an interesting class of halide double perovskites (DPs) have recently been in the hot list of photovolatic (PV) researchers. This article presents 27 Cs2BB′X6 halide DPs using different exchange–correlation approximations and reports investigations based on factors such as the Goldschmidt tolerance factor (t) and modified tolerance factor (t′) and thermodynamical investigations considering mixed decomposition pathways for assessing their stability. The spin–orbit coupling (SOC) is explored to understand the role of the heavy element as an alternative to Pb. A wide range of band gaps (0.2 eV to 2.35 eV) are noticed for the 27 DPs. As a single exception, a halide DP with a trivalent thallium cation exhibits metallic characteristics. Further, an insight into the mechanism behind band gap variation is correlated with different B/B′/X combinations and understood from molecular orbital alignment analysis. Such a broad band gap spectrum has the potential to provide the possibility of integrating them in single- or multiple-junction solar cells or thermoelectric applications. This article, on the whole, hopefully provides insights into the potential of DPs for various applications befitting their particular material properties.

Dinitrogen-derived (diarylboryl)diazenido complexes with differing coordination to the thallium cation.

To prepare N2-derived cationic boryldiazenido-tungsten complexes as models of semimetallic metal-borinium frustrated Lewis pairs activating N2, we have attempted halide abstraction from trans-(diarylboryl)diazenido-halo-tungsten complexes. Reactions with Tl+ led to adducts in which coordination of the cation differs depending on the boryldiazenide substituents and the ancillary ligand. Chloride scavenging was not observed.

Reaction of the Thallium(I) Cation with [2.2]Paracyclophane: Experimental and Theoretical Study

Reaction of the Thallium(I) Cation with [2.2]Paracyclophane: Experimental and Theoretical Study

To chelate thallium(I) - synthesis and evaluation of Kryptofix-based chelators for 201Tl.

While best known for its toxic properties, thallium has also been explored for applications in nuclear diagnostics and medicine. Indeed, [201Tl]TlCl has been used extensively for nuclear imaging in the past before it was superceded by other radionuclides such as 99mTc. One reason for this loss of interest is the severe lack of suitable organic chelators able to effectively coordinate ionic forms of Tl and deliver it to specific diseased tissue by means of attached biological vectors. Herein, we describe the synthesis and characterisation of a series of Kryptofix 222-based chelators that can be radiolabelled with 201Tl(I) in high radiochemical yields at ambient temperature. We demonstrate that from these simple chelators, targeted derivatives are readily accessible and describe the synthesis and preliminary biological evaluation of a PSMA-targeted 201Tl-labelled Kryptofix 222-peptide conjugate. While the Kryptofix system is demonstrably capable of binding the thallium cation, no PSMA-mediated cell-uptake could be detected with the PSMA conjugate, suggesting that this targeting moiety may not be ideal for use in conjunction with 201Tl.

Peculiarities of ionic mobility and superionic conductivity in Thallium(I) Fluoroantimonates(III). A review

The present analytical review has been revised according to the results of studies on the nature of ionic mobility and conductivity in complex antimony(III) fluorides with thallium cations. The studies have been carried out at the Institute of Chemistry of the Far Eastern Branch of the Russian Academy of Sciences. The relationship between the NMR data, ionic mobility, and conductivity of the compounds has been determined. The suggested mechanisms of the appearance of ionic mobility in the studied antimony fluorides have been investigated, and the factors determining their conductivity have been analyzed. The possibility of using antimony(III) fluorides with thallium(I) cations as functional materials has been discussed.

Crystal structure of poly[(μ3-4-amino-1,2,5-oxa-diazole-3-hydroxamato)thallium(I)

The title compound represents the thallium(I) salt of a substituted 1,2,5-oxa-diazole, [Tl(C3H3N4O3)] n , with amino- and hydroxamate groups in the 4- and 3- positions of the oxa-diazole ring, respectively. In the crystal, the deprotonated hydroxamate group represents an inter-mediate between the keto/enol tautomers and forms a five-membered chelate ring with the thallium(I) cation. The coordination sphere of the cation is augmented to a distorted disphenoid by two monodentately binding O atoms from two adjacent anions, leading to the formation of zigzag chains extending parallel to the b axis. The cohesion within the chains is supported by π-π stacking [centroid-centroid distance = 3.746 (3) Å] and inter-molecular N-H⋯N hydrogen bonds.

Meso-Octamethylcalix[4]pyrrole as an effective macrocyclic receptor for the univalent thallium cation in the gas phase: Experimental and theoretical study

By using electrospray ionization mass spectrometry (ESI-MS), it was proven experimentally that the univalent thallium cation (Tl+) forms with meso-octamethylcalix[4]pyrrole (1) the cationic complex species 1 Tl+. When this kinetically stable cation-π complex 1 Tl+ is collisionally activated, it decomposes by elimination of the whole ligand 1 or small meso-octamethylcalix[4]pyrrole fragments. Further, applying quantum chemical DFT calculations, four different conformations of the resulting complex 1 Tl+ were derived. It means that under the present experimental conditions, this ligand 1 can be considered as a very effective macrocyclic receptor for the thallium cation.

Accessing Low-Valent Inorganic Cations by Using an Extremely Bulky N-Heterocyclic Carbene.

The extremely bulky N-heterocyclic carbene (NHC), ITr (ITr=[(HCNCPh3 )2 C:]) featuring sterically shielding umbrella-shaped trityl (CPh3 ) substituents was prepared. This NHC features the highest percent buried volume (%Vbur ) to date, and was used to form a thermally stable quasi one-coordinate thallium(I) cation [ITr-Tl]+ . This TlI adduct and the corresponding lithium complex [ITr⋅Li(OEt2 )]+ are versatile "all-in-one" transmetalation/ligation reagents for preparing low-coordinate inorganic species inaccessible by pre-existing routes.

Experimental and Theoretical Study of the Complexation of Cesium and Thallium Cations by a Water-Soluble Cryptophane

Cs (cesium) and Tl (thallium) are known to be very toxic for the environment and human health. Thus, the synthesis of molecular receptors aimed at extracting these two elements from the environment is strongly desired. In this Article, we report the synthesis of the two enantiomers of cryptophane-223(OH)$_7$ (1) and the study of their interaction with cesium and thallium cations in basic aqueous solutions. These two complexes have been studied by $^{133}$Cs and $^{205}$Tl NMR spectroscopy to reveal the complexation of the two metallic cations and by chiroptical techniques (electronic and vibrational circular dichroism) to provide valuable information about the conformational changes occurring during the binding process. The thermodynamic parameters of complexation K, $\Delta $$H^0$ and $\Delta $$S^0$ obtained from titration experiments reveal a strong interaction between 1 and the two cations under a large range of experimental conditions. A decomposition of the total binding energy, performed by DFT calculations, allows us to characterize the nature of the interactions existing between the cage-molecule and these two cations. These calculations also reveal the importance of the spin-orbit coupling for predicting correctly the large frequency difference between the free Tl$^+$ and Tl$^+$@1 NMR signals and to understand its origin. In addition to the development of a methodology enabling detailed understanding of the host-guest interaction, this study indicates a very pronounced selectivity of this cage-molecule towards both Cs$^+$ and Tl$^+$ cations in various experimental conditions.

A combined experimental and quantum chemical study on thallium(I) tris(pyrazolyl)methanide

Density functional theory methods have been applied to identify the favoured structural motif of thallium(I) tris(pyrazolyl)methanide complexes. The reaction of [TlN(SiMe3)2]2 with tris(pyrazolyl)methane HC(pz)3 (with pz=pyrazolyl) in toluene furnished the highly air-sensitive title compound [Tl(HTpmd)] (4) (with HTpmd=[C(pz)3]−). An X-ray diffraction study revealed that complex 4 consists of a single bond between the thallium(I) cation and the carbanion of HTpmd ligand entity. This Tl–C bond (254.1(8)pm) is supported by two additional Tl⋯N contacts (Tl⋯N: 273.6(7) and 293.1pm) provided by the N donor atoms of two pyrazolyl scaffolds of the tripodal ligand. Overall, a κ2N,κ1C coordination mode of the tris(pyrazolyl)methanide ligand is at hand in complex 4. Furthermore, the title compound forms a weak dimer in the solid-state by additional intermolecular Tl⋯N′ interactions (318.7pm).

Extraction and DFT study on interaction of the univalent thallium cation with calix[4]arene-(1,2-phenylene-crown-6,crown-6)

On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Tl+ (aq)+1·Cs+ (nb)⇄1·Tl+ (nb)+Cs+ (aq) occurring in the two-phase water–nitrobenzene system (1=calix[4]arene-(1,2-phenylene-crown-6,crown-6); aq=aqueous phase, nb=nitrobenzene phase) was determined as log Kex(Tl+,1·Cs+)=0.4±0.1. Further, the very high stability constant of the 1·Tl+ complex in nitrobenzene saturated with water was calculated for a temperature of 25°C: log β(1·Tl+)=9.9±0.2. Finally, by using quantum mechanical DFT calculations, the most probable structures A and B of this cationic complex species, which are obviously in a dynamic equilibrium, were derived.

A Translational Biomedical Approach to Structural Arrangement of Amino Acids Complexes: A Combined Theoretical and Computational Study

In this short communication, respectively bonding among Boron (B3+), Aluminum (Al3+), Gallium (Ga3+), Indium (In3+) and Thallium (Tl3+) cations and Alanine, Arginine, Asparagine, Aspartic Acid, Cysteine, Glutamic Acid, Glutamine, Glycine, Proline, Selenocysteine, Serine, Tyrosine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan and Valine ligands and also structural arrangement of the present compounds were studied, theoretically and computationally

Experimental and theoretical study on cation–π interaction of the univalent thallium cation with [2.2.2]paracyclophane

By using electrospray ionization mass spectrometry (ESI-MS), it was proven experimentally that the univalent thallium cation (Tl+) forms with [2.2.2]paracyclophane (C24H24) the cationic complex species [Tl(C24H24)]+. Further, employing quantum mechanical DFT calculations, the most probable structure of the [Tl(C24H24)]+ complex was derived. In the resulting complex with a symmetry very close to C3, the ‘central’ cation Tl+ is bound by six bonding interactions to six carbon atoms from the three benzene rings of the parent [2.2.2]paracyclophane ligand via cation–π interaction.

Cation-π interaction of Tl+ with [6]helicene: Experimental and DFT study

By using electrospray ionization mass spectrometry (ESI-MS), it was proven experimentally that the univalent thallium cation forms with [6]helicene (C26H16) the cationic complex species [Tl(C26H16)]+ in the gas phase. Further, applying quantum mechanical DFT calculations, the most probable structure of the [Tl(C26H16)]+ complex was derived. In the resulting complex, the “central” cation Tl+ is bound by six bonds to six carbon atoms from the two terminal benzene rings of the parent [6]helicene ligand via cation-π interaction. Finally, the interaction energy, E(int), of the considered cation-π complex [Tl(C26H16)]+ was found to be −144.8 kJ/mol, confirming the formation of this cationic complex species as well.