Tl Coordination Research Articles

The Role of Prussian Blue-Thallium and Potassium Similarities and Differences in Crystal Structures of Selected Cyanido Complexes of W, Fe and Mo.

The synthesis and single X-ray crystal structures of Tl2[W(CN)6(bpy)]·H2O, Tl[W(CN)6(bpy)], Tl57[{Fe(CN)6}12{NO3}9]·9H2O, Tl4[W(CN)8] and Tl4[Mo(CN)8] are described. Salts crystalize in the monoclinic or trigonal (Fe) space group. For all complexes, the very unusual “side-on” coordination of Tl to C and N of cyanido ligands is observed and compared to potassium cations. The very strong bonding to cyanido ligands with an 8–13 coordination number of thallium is described and discussed. The difference between potassium and thallium bonding is an indication of the biological activity of thallium and the role of Prussian blue in the thallium detoxification procedure.

Modular Crystal Chemistry of Thallium Sulfosalts

Complex sulfides of thallium with As, Sb, or Bi and with other cations (‘thallium sulfosalts’) are a large group of crystal structures with extreme variability. Incorporation of the large Tl+ cation in them is solved in several different ways: housing of Tl in columns of capped trigonal coordination prisms, which form separate walls in the structure (in different combinations with Pb and/or Sb), regular alternation of large Tl with small cations (As), presence of structural arrays of Tl coordination polyhedra paralleled by arrays of As coordination pyramids with a frequency ratio 1:2, omission derivatives with cavities for Tl accommodation and formation of layer structures with thallium concentrated into separate (inter)layers of different types. The first principle leads to a large family of sartorite homologues and rare lillianite homologues, as well as to the chabournéite group. The second one to the hutchinsonite family, omission derivatives form the routhierite and galkhaite groups, and the 1:2 periodicity ratio principle results in several outstanding structures from different groups. Layer structures consist of two-component and three-component layer combinations. Close cation-cation interactions are present but rare.

Crystal formation features in a series of chalcogenide structures with monovalent Tl. Ordered packing effect in Tl coordination

In order to determine the crystal- forming factors and reasons for irregular coordination of Tl+ cations the crystallographic analysis of the structure of AgTlTe (I), minerals vrbaite Hg3Tl4As8Sb2S20 (II) and gabrielite Tl2AgCu2As3S7 (III) is performed. For I and II the skeleton translational sublattices of all atoms in the structure with the determining contribution of Tl+ and anions are found; for II and III the cationic and anionic along with Tl+ sublattices, which form the structure, are found. The incorporation of cations into the Tl+ coordination environment is classified as a consequence of the structure-forming ordering of Tl cations and anions (S, Te) in one matrix, i.e. as the effect of their ordered packing.

Tl-bearing sulfosalt from the Lengenbach quarry, Binn Valley, Switzerland: Philrothite, TlAs3S5

AbstractPhilrothite, ideally TlAs3S5, is a new mineral from the Lengenbach quarry in the Binn Valley, Valais, Switzerland. It occurs as very rare crystals up to 200 mm across on realgar associated with smithite, rutile and sartorite. Philrothite is opaque with a metallic lustre and shows a dark brown streak. It is brittle; the Vickers hardness (VHN25) is 128 kg/mm2(range: 120–137) (Mohs hardness of 3–3½). In reflected light philrothite is moderately bireflectant and weakly pleochroic from dark grey to light grey. Under crossed polars it is anisotropic with grey to bluish rotation tints. Internal reflections are absent. Reflectance percentages for the four COM wavelengths (RminandRmax) are: 26.5, 28.8 (471.1 nm), 25.4, 27.2 (548.3 nm), 24.6, 26.3 (586.6 nm) and 24.0, 25.1 (652.3 nm), respectively.Philrothite is monoclinic, space groupP21/c, witha= 8.013(2),b= 24.829(4),c= 11.762(3) Å,β= 132.84(2)°,V= 1715.9(7) Å3,Z= 8. It represents theN= 4 homologue of the sartorite homologous series. In the crystal structure [R1= 0.098 for 1217 reflections withI> 2σ(I)], Tl assumes tricapped prismatic sites alternating to form columns perpendicular to the b axis. Between the zigzag walls of Tl coordination prisms, coordination pyramids of As(Sb) form diagonally-oriented double layers separated by broader interspaces which house the lone electron pairs of these elements.The eight strongest calculated powder-diffraction lines [din Å(I/I0) (hkl)] are: 12.4145 (52) (020); 3.6768 (100) (61); 3.4535 (45) (131); 3.0150 (46) (53); 2.8941 (52) (81); 2.7685 (76) (230); 2.7642 (77) (34); 2.3239 (52) (092). A mean of five electron microprobe analyses gave Tl 26.28(12), Pb 6.69(8), Ag 2.50(4), Cu 0.04(2), Hg 0.07(2), As 32.50(13), Sb 3.15(3), S 26.35(10), total 97.58 wt.%, corresponding, on the basis of a total of nine atoms, to (Tl0.789Pb0.198)∑=0.987(As2.662Sb0.159Ag0.142Cu0.004Hg0.002)∑=2.969S5.044. The new mineral has been approved by the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association (2013-066) and named for Philippe Roth (b. 1963), geophysicist and well known mineral expert on the Lengenbach minerals for more than 25 years.

Poly[[tris(μ2-4,4′-bipyridineN,N′-dioxide)hexanitratodigadolinium(III)] dichloromethane disolvate

The title one-dimensional coordination network, {[Gd2(NO3)6(C10H8N2O2)3]·2CH2Cl2}n, is isostructural with the previously reported Tb and Tl coordination networks and to its Eu analog. The GdIII cation is coordinated in a distorted tricapped trigonal-prismatic fashion by nine O atoms from three bridging 4,4′-bipyridine N,N′-dioxide ligands and three chelating nitrate anions. None of the atoms lie on a special position, but there is an inversion center located between the rings of one of the ligands. The network topology is ladder-like, and each ladder inter­acts with six neighboring ladders through C—H⋯O hydrogen bonds. The packing motif of the ladders allows for the formation of channels that run parallel to the a axis; these channels are filled with CH2Cl2 solvent mol­ecules that inter­act with the ladders through C—H⋯O hydrogen bonds

Poly[[tris(μ2-4,4′-bipyridineN,N′-dioxide)hexanitratodieuropium(III)] dichloromethane disolvate

The title one-dimensional coordination network, {[Eu2(NO3)6(C10H8N2O2)3]·2CH2Cl2}n, is isostructural with the previously reported Tb and Tl coordination networks and to its Gd analog. The EuIII cation is coordinated in a distorted tricapped trigonal-prismatic fashion by nine O atoms from three bridging 4,4′-bipyridine N,N′-dioxide ligands and three chelating nitrate anions. None of the atoms lie on a special position, but there is an inversion center located between the rings of one of the ligands. The network topology is ladder-like, and each ladder inter­acts with six neighboring ladders through C—H⋯O hydrogen bonds. The packing motif of the ladders allows for the formation of channels that run parallel to the a axis; these channels are filled with CH2Cl2 solvent mol­ecules that inter­act with the ladders through C—H⋯O hydrogen bonds.

Synthesis and Crystal Structure of the First Thallium Hydrous Nesosilicate Tl4SiO4·0.5H2O

AbstractOrange prismatic crystals of the first thallium hydrous nesosilicate Tl4SiO4·0.5H2O have been obtained by evaporation from aqueous solution. There are three symmetrically independent Tl+ cations and five symmetrically independent oxygen atoms in the structure of Tl4SiO4·0.5H2O. The O(4) and O(5) atoms belong to water molecules. Coordination polyhedra of the Tl+ cations are strongly distorted because of the stereoactive behavior of lone electron pairs. The structure of Tl4SiO4·0.5H2O contains sheets of SiO4 tetrahedra and Tl coordination polyhedra. The sheets have the composition [Tl3SiO4]– and are parallel to [100]. Within the sheets, SiO4 tetrahedra link to thallium polyhedra though common corners. The sheets are linked by dimers of face‐sharing Tl(3)O5 polyhedra, thus providing interconnection of the sheets into a framework. The framework has large elliptical channels occupied by water molecules (OW2) and electron pairs of Tl+ cations.The comparison with some other M+ (M = K, Ag, Tl) silicates is given.

Crystal Structure of Tl2[(UO2)2(MoO4)3] and Crystal Chemistry of the Compounds M2[(UO2)2(MoO4)3] (M = Tl, Rb, Cs)

A new compound, Tl2[(UO2)2(MoO4)3], was prepared by a solid-phase reaction. The compound crystallizes in a rhombic system, space group Pna21, a = 20.1296(9), b = 8.2811(4), c = 9.7045(4), V = 1617.69(13) A3, Z = 4. The crystal structrue was solved by the direct method and refined to R 1 = 0. 04 for 4884 unique reflections. The structural motif is a framework consisting of UO7 pentagonal bipyramids and MoO4 tetrahedra. The Tl coordination polyhedra are irregular, with seven and eight vertices. Large channels of the size 6 × 10.8 A, occupied by Tl+ cations, are arranged parallel to the [001] direction. The compound is isostructural to the previously described α-Cs2(UO2)2(MoO4)3 and Rb2(UO2)2 (MoO4)3.

Electronic Band Structure of TlTe

We report about self-consistent ab initio LMTO-ASA calculations of the electronic band structure and the crystal orbital Hamiltonian population function COHP. The calculations support a view of TlTe as an univalent Tl compound with two polyanionic partial structures, linear branched and unbranched chains, characterized by 3c–4e type of bonding, both within the chains and within the branches. The system deviates from classical Peierls-type systems with respect to the lack of energetic separation of the two types of transition-driving σ bands due to the appearance of nonintrachain bands close to EF. Tl coordination causes the lack of elastic degrees of freedom, which prevents the system from introducing completely alternating chains in one step. The branched Te2 chains are shown to be favored for pairing distortion compared to Te3 chains as a result of the weaker Tl–Te2 interactions. The distortion is interpreted as a dimerization of (Te3)3− units to form a new type of 42 electron (Te6)6− partial structure not known in polyhalogenide or noble gas halogenide chemistry.

Voltammetric studies of the reactions of iron–sulphur clusters ([3Fe-4S] or [M3Fe-4S]) formed in Pyrococcus furiosus ferredoxin

Reactions of the [3Fe-4S] cluster and various metallated [M3Fe-4S] adducts co-ordinated in the ferredoxin from the hyperthermophile Pyrococcus furiosus have been studied by protein-film voltammetry, bulk-solution voltammetry, solution kinetics and magnetic CD (MCD). The [3Fe-4S] cluster exhibits two couples, [3Fe-4S]+/0 and [3Fe-4S]0/2-. Film voltammetry is possible over a wide pH range (2-8), revealing that the [3Fe-4S]+/0 couple shows a complex pH dependence with pKred1=2.8, pKox=4.9 and pKred2=6.7. From MCD, pKred1 corresponds with protonation of [3Fe-4S]0 to give a spectroscopically distinct species, as reported for ferredoxins from Azotobacter and Sulfolobus. The status of the disulphide/disulphydryl entity makes no significant difference to the data (given for the -S-S- form). Formation of the hyper-reduced [3Fe-4S]2- state is observed, requiring 3H+ for the overall 3e- reduction of [3Fe-4S]+, the change therefore being electroneutral. By comparison with the ferredoxin from Desulfovibrio africanus, uptake of Fe(II) and other M(II) by [3Fe-4S]0 to give [M3Fe-4S] clusters is slow (t1/2>10 min at room temperature, slower still if the protein is adsorbed on the electrode), whereas reaction with Tl(I) to produce [Tl3Fe-4S] is very rapid (t1/2<<1 s), suggesting that co-ordination of Tl does not require reorganization of the protein structure. Rates of formation of [3Fe-4S] from [M3Fe-4S] adducts increase sharply at high potentials, showing that metal release involves a labile 'super-oxidized' [M3Fe-4S]3+ state.

The photoelectron spectra of some Tl-Sb sulphosalts

The results of X-ray induced photoelectron spectroscopy (XPS) experiments on several phases of the ternary system Tl-Sb-S are reported. The binding energies of the inner S, Sb and Tl electrons increase with increasing quantities of Sb and decreasing amounts of Tl in these compounds. This is explained by the influences of the proportions of the bonded metals on the effective electron affinity of S. The higher proportions of the more electronegative element bonded to S cause the increase of its effective electron affinity. The results for Tl2S (carlinite), Tl3SbS3, TlSbS2 (weissbergite), TlAsS2 (lorandite) and Sb2S3 (antimonite) can be interpreted in this way. The results for Tl4S3 suggest a predominantly covalent character of bonding for both Tl(III) and Tl(I), which are present in this sulfide. From comparison with Tl3SbS4 it could be supposed that Tl(III)-S bond has a more covalent character than Sb(V)-S bond. The results for Tl3SbS4 are in agreement with crystal structure data and the results of Moessbauer spectroscopy. For AsS (realgar) the binding energies of the inner electrons of As and S significantly increase, showing that the electrons in molecular orbitals are less strongly bonded to individual atoms, as compared to pure elements. The results for the amorphous TlSb5S8 (corresponding in composition to parapierrotite) suggest that in amorphous compound the Tl-S bonding is stronger and the coordination of Tl more regular than in a crystalline one.

The crystallochemical behaviour of thallium and lead in the lorandite-type sulfosalts

The accumulated data on the crystal structures of sulfosalts show that in most cases Tl and Pb atoms have coordinations which can be correlated to the same general type as the coordinations of Bi, Sb and As. This explains the possibility of the mutual substitution of these elements in structures of sulfosalts.The coordinations of Tl and Pb are distinguished by the longer bonds in the case of Tl (especially when the closest neighbours are considered) and sometimes by the special geometry of the Tl coordination polyhedron.The coordination sphere of Tl in lorandite and the related Tl sulfosalts is similar to that of Pb in a number of sulfosalts. However, the structures of some sulfosalts in which both Tl and Pb are the main constituents show that they tend to occupy symmetrically nonequivalent positions, their distribution being governed by the most appropriate valency/charge distribution through the structure.From the observed facts it can be suspected that Pb atoms in a host Tl sulfosalt structure of the lorandite type would concentrate in the areas of structural defects or migrate to the surface of the grains during the diffusion processes.

Reaction of 3,6-tert-butyl-o-benzosemiquinone with molybdenum and chromium hexacarbonyls; EPR spectra of anion-radical complexes

1. The formation of previously unknown anion-radical complexes of molybdenum with pyrocatechol ligands has been demonstrated. 2. Treatment of 3,6-di-tert-butyl-o-quinone anion-radicals with Cr(CO)6 leads to the formation of anion radical mono-, bis-, and tris(ligand) chromium complexes. 3. The nature of coordination of Tl+ with the oxygen atoms of the o-semiquinone ligand in the complex\(Cr(3,6 - DTBQ)^{\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{ - } } _3 T1^ +\) has been inferred from an analysis of the hyperfine splitting constant values for the unpaired electron with the magnetic moment of the thallium nucleus.

Aspects of transmetallation reactions of 2-Me 2NCH 2C 6H 4- and 2,6-(Me 2NCH 2)C 6H 3-Metal (Pd, Pt, Hg, Tl) complexes with metal carboxylates and low-valent metal (Pd, Pt) complexes

A study has been made of reactions involving organometallic compounds containing ortho-Me 2NCH 2 substituted aryl ligands. The single step syntheses of the new compounds [(2-Me 2NCH 2C 6H 4) 2TlCl], [ [{( S)-2-Me 2NCH(Me)C 6H 4} 2TlCl], [{( S)-2-Me 2NCH(Me)C 6H 4}TlCl 2], [{2,6-(Me 2NCH 2) 2C 6H 3}TlClBr] and [{2,6-(Me 2NCH 2) 2C 6H 3}HgCl] are described. Stable internal NTl coordination at low temperatures has been established for the C-chiral thallium compounds. Reactions of the other Tl and Hg compounds and of [(2-Me 2NCH 2C 6H 4) 2Hg] with Pd(O 2CMe) 2, and also of the reverse reaction of cis-[(2-Me 2NCH 2C 6H 4) 2Pd] with Hg(O 2CR) 2 or Tl(O 2CR) 3, gave transmetallation of one organo ligand and led to a single mono-organopalladium compound and corresponding by-products. Reaction of cis-[( 2-Me 2NCH 2C 6H 4) 2Pd] with Pd(O 2CR) 2 gave the dimeric compound [{(2-Me 2NCH 2C 6H 4)Pd(O 2CR)} 2]. cis-[(2-Me 2NCH 2C 6H 4) 2Pt] did not react with Pd(O 2CMe) 2, while reaction of trans-[(2-Me 2NCH 2C 6H 4) 2Pt] or cis-[(2-Me 2NC 6H 4CH 2) 2Pt] with Pd(O 2CMe) 2 resulted in decomposition. Upon heating, trans-[(2-Me 2NCH 2C 6H 4) 2Pt] was isomerized to cis-isomer. A redox reaction between [(2-Me 2NCH 2C 6H 4) 2Hg] and [Pt(COD) 2] (COD  1,5-cyclo-octadiene) and [Pd 2(DBA) 3] (DBA  dibenzylideneacetone) gave the cis-isomers of [(2-Me 2NCH 2C 6H 4) 2M] (M  Pd, Pt). The results are discussed in terms of influence of internal coordination of the CH 2NMe 2 group. It is concluded that although internal coordination of the CH 2NMe 2 ligand can stabilize metal—carbon bonds it cannot prevent cleavage of such bonds by electrophiles. In this respect, there is no difference in the behaviour of Hg(O 2CR) 2 and Tl(O 2CR) 3. The reactions are influenced by the metal—nitrogen bond strength, which follows the order PtN > PdN > HgN, TlN. The reactivity of Pt compounds is greatly influenced by their structure and type of ligand. It is proposed that cleavege of PdC bonds occurs mainly by a mechanism involving direct electrophilic attack at the carbon centre.

Cinétique d'oxydation des oximes du benzaldéhyde et de l'acétophénone par l'ion thallique

The kinetics of oxidation of benzaldehyde and acetophenone oximes by Tl(III) in aqueous medium has been studied. The reaction occurs in two consecutive steps: formation of a nitroso intermediate and its decomposition. The oxime forms a complex with Tl(III) leading to the rate equation: −d[oxime]/dt = K1/k2[oxime][Tl(III)]/(1 + K1[Tl(III)]). The formation of the final carbonyl product is inhibited by Tl(III), a resuit of the formation of a complex resistant to decomposition. Coordination of Tl(III) by chloride ions affects the rate of the above two steps. The reaction mechanism is discussed. [Journal translation]

Die Kristallstruktur des Thallium(I)thiogermanats Tl4GeS4

Abstract Tl4GeS4 is monoclinic, space group Cc with a = 12.501(3), b = 11.248(2), c = 7.608(3) Å, β = 112.21(2)° and Z = 4. The crystal structure was determined from four-circle diffractometer intensity data by means of direct methods and refined to R = 0.066. The structure is characterized by isolated tetrahedral anions GeS4 4− held together by T1+ ions. The mean Ge–S bond length is 2.216 Å. Together with one of the Tl atoms, the GeS4 tetrahedra are situated in slabs parallel to (100) alternating with other slabs which contain the remaining three Tl atoms. The metal atoms are surrounded by six S atoms at distances between 2.92 and 3.89 Å. In their environments there are also three to five Tl+ ions at distances between 3.454 and 3.891 Å. The Tl coordination polyhedra are highly irregular.

On the Mechanism and Substituent Effects of the Tl(III) Oxidation of Phenylethylenes in Methanol

The oxidation of phenylethylenes by Tl(NO3)3 in methanol proceeds rapidly and selectively to give the products resulting from the migration of aryl groups, i.e., (i) the 1,1-dimethoxy-2-phenylethanes from the corresponding styrenes, (ii) the phenylacetones from the α-methylstyrenes, and (iii) the two possible deoxybenzoines from the 1,1,-diphenylethylenes. The kinetic results, which indicate the formation of the thallic–organic intermediate to be the rate determining step, are discussed in terms of the mechanism of reaction and show the role of the coordination of Tl(III). Hammett's relationship, with ρ = −4.2, describes the substituent effects for the competitive oxidation of ring-substituted styrenes and α-methylstyrenes. The relative migratory aptitudes of aryl groups, as determined from the oxidation products of ring-substituted 1,1-diphenylethylenes, is correlated to Brown's σ+ constants, with ρ+ = −2.27.