Depolymerization of Aryltellurinic Anhydrides with Sodium Hydroxide. Synthesis and Structure of the Hydrated Sodium Aryltellurinates [Na(H2O)4](RTeO2) (R = 4-MeOC6H4, 8-Me2NC10H6)

N-Coordinated tellurenium(II) and telluronium(IV) cations: synthesis, structure and hydrolysis

A set of N-coordinated tellurium(II) compounds containing either C,N-chelating ligands CNR (where CN = 2-(RNCH)C6H4, R = tBu or Dipp; Dipp = 2,6-iPr2C6H3) or N,C,N pincer ligands NCNR (where NCN = 2,6-(RNCH)2C6H4, R = tBu or Dipp) were synthesized. In the case of C,N-chelated compounds, the reaction of CNDippLi with Te(dtc)2 (where dtc = Et2NCS2) in a 1 : 1 molar ratio smoothly provided the carbamate CNDippTe(dtc) which upon treatment with 2 eq. of HCl provided the chloride CNDippTeCl. In contrast, the analogous conversion of NCNRLi with Te(dtc)2 surprisingly furnished ionic bromides [NCNRTe]Br as a result of the exchange of dtc by Br coming from nBuBr present in the reaction mixture. Furthermore, the reaction of CNDippTeCl or [NCNRTe]Br with silver salts AgX (X = OTf or SbF6) provided the expected tellurenium cations [CNDippTe]SbF6 and [NCNRTe]X. To further increase the Lewis acidity of the central atom, the oxidation of selected compounds with 1 eq. of SO2Cl2 was examined yielding stable compounds [CNtBuTeCl2]X and [NCNtBuTeCl2]X. The oxidation of the Dipp substituted compounds proved to be more challenging and an excess of SO2Cl2 was necessary to obtain the oxidized products [CNDippTeCl2]SbF6 and [NCNDippTeCl2]SbF6, which could solely be characterized in solution. Compounds [CNtBuTeCl2]OTf and [NCNtBuTeCl2]OTf were shown to undergo a controlled hydrolysis to the corresponding telluroxanes. All compounds were studied by multinuclear NMR spectroscopy in solution and for selected compounds solid state 125Te NMR spectroscopy and single-crystal X-ray diffraction analysis were performed. The Lewis acidity of the studied cations was examined by the Gutmann-Beckett method using Et3PO as the probing agent. The Te-N chalcogen bonding situation of selected compounds has also been examined computationally by a set of real-space bonding indicators.

Spontaneous formation of a chiral (Mo2O2S2)2+-based cluster driven by dimeric {Te2O6}-based templates

Utilization of tellurite anion as template, led to the formation of unprecedented oxothiometalate based building blocks and the spontaneous manifestation of chirality.

Utilization of [Mo₂S₂O₂(H₂O)₆]²⁺ and a tellurite anion led to the formation of three new clusters, 1–3, with unique structural features. The tellurite anion not only templated the formation of [(Mo₂O₂S₂)₄(TeO₃)(OH)₉]^3–1 and [(Mo₂O₂S₂)₁₂(TeO₃)₄(TeO₄)₂ (OH)₁₈]^10–3, but also the in situ generation of two different types of dimeric {Te₂O₆} based moieties induced the spontaneous assembly of the chiral [(Mo₂O₂S₂)₁₀(TeO₃)(Te₂O₆)₂(OH)₁₈]^8– anionic cluster, 2.

Unraveling the Organotellurium Chemistry Applied to the Synthesis of Gold Nanomaterials

Long-term preservation of the properties of gold nanoparticles in both solution and the dry powder form can be difficult. We have overcome this challenge by using organotellurium derivatives as both reducing agents and stabilizers in the synthesis of gold nanoparticles. This new synthetic protocol takes advantage of the photochemical and oxidative properties of diphenyl ditelluride (Ph₂Te₂), which, so far, have never been exploited in the synthesis of gold nanoparticles. The Au/Te core/shell (inorganic/organic) hybrid nanomaterial can be obtained in a one-step reaction, using only Ph₂Te₂ and HAuCl₄. By modifying the reaction conditions, different resonance conditions of the gold core are achieved due to the formation of external shells with different thicknesses. The organotellurium shell can be easily removed by resuspension of the nanoparticles in environmentally friendly solvents, such as water or ethanol, making the Au core available for subsequent applications. A mechanism for the formation of core/shell nanoparticles has also been discussed.

Crystal structure of poly[[di-μ2-aqua-aquasodium] 4-amino-3,5,6-trichloropyridine-2-carboxylate trihydrate], the sodium salt of the herbicide picloram

The trihydrated sodium salt of the herbicide picloram comprises a cationic μ₂-aqua-bridged chain structure that is linked to the picloramate anions through amine N—H⋯O and water O—H⋯O and O—H⋯N hydrogen bonds.

In the structure of the title complex, {[Na(H₂O)₃](C₆H₂Cl₃N₂O₂)·3H₂O}_n, the sodium salt of the herbicide picloram, the cation adopts a polymeric chain structure, based on μ₂-aqua-bridged NaO₅ trigonal–bipyramidal complex units which have, in addition, a singly bonded water mol­ecule. Each of the bridges within the chain, which extends parallel to the a axis, is centrosymmetric, with Na⋯Na separations of 3.4807 (16) and 3.5109 (16) Å. In the crystal, there are three water mol­ecules of solvation and these, as well as the coordinating water mol­ecules and the amino group of the 4-amino-3,5,6-tri­chloro­picolinate anion, are involved in extensive inter-species hydrogen-bonding inter­actions with carboxyl and water O atoms, as well as the pyridine N atom. Among these associations is a centrosymmetric cyclic tetra­water R₄⁴(8) motif, resulting in an overall three-dimensional structure.

Reaction of L2Zn2 with Ph2E2 – synthesis of LZnEPh and reactions with oxygen and H-acidic substrates

L₂Zn₂ (L = HC[C(Me)N(2,4,6-Me₃C₆H₂)]₂) and Ph₂E₂ (E = Se, Te) react to form LZnSePh (1) and LZnTePh (2).