The pentafluorooxotellurate compound ReO(2)(OTeF(5))(3) has been synthesized from the reaction of ReO(2)F(3) with B(OTeF(5))(3) and structurally characterized in solution by (19)F and (125)Te NMR spectroscopy and in the solid state by Raman spectroscopy. The NMR and vibrational spectroscopic findings are consistent with a trigonal bipyramidal arrangement in which the oxygen atoms and an OTeF(5) group occupy the equatorial plane. The (19)F and (125)Te NMR spectra show that the axial and equatorial OTeF(5) groups of ReO(2)(OTeF(5))(3) are fluxional and are consistent with intramolecular exchange by means of a pseudorotation. The Lewis acid behavior of ReO(2)(OTeF(5))(3) is demonstrated by reaction with OTeF(5)(-). The resulting cis-ReO(2)(OTeF(5))(4)(-) anion was characterized as the tetramethylammonium salt in solution by (19)F and (125)Te NMR spectroscopy and in the solid state by Raman spectroscopy and X-ray crystallography. The compound crystallizes in the triclinic system, space group P&onemacr;, with a = 13.175(7) Å, b = 13.811(5) Å, c = 15.38(1) Å, alpha = 72.36(5)(o), beta = 68.17(5)(o), gamma = 84.05(4)(o), V = 2476(2) Å(3), D(calc) = 3.345 g cm(-)(3), Z = 4, R = 0.0547. The coordination sphere about Re(VII) in cis-ReO(2)(OTeF(5))(4)(-) is a pseudooctahedron in which the Re-O double bond oxygens are cis to one another.
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http://dx.doi.org/10.1021/ic960597c | DOI Listing |
ACS Omega
September 2023
São Carlos Institute of Chemistry-IQSC, University of São Paulo-USP, São Carlos 13560-970, SP, Brazil.
Tellurite glasses have garnered considerable interest as optical host materials due to their advantageous properties, including low processing temperature, high resistance to corrosion and crystallization, and excellent solubility for rare earth ions. However, their applicability in the infrared (IR) region is limited by the absorption of species with distinct vibrations. The incorporation of fluorides has emerged as a promising approach to reduce hydroxyl (OH) absorption during the precursor melting process.
View Article and Find Full Text PDFIn the field of noncovalent interactions, chalcogen bonding (ChB) involving the tellurium atom is currently attracting much attention in supramolecular chemistry and in catalysis. However, as a prerequisite for its application, the ChB should be studied in solution to assess its formation and, if possible, to evaluate its strength. In this context, new tellurium derivatives bearing CHF and CF groups were designed to exhibit Te⋯F ChB and were synthesized in good to high yields.
View Article and Find Full Text PDFDalton Trans
February 2023
Department of Chemistry and Molecular Physics, São Carlos Institute of Chemistry - IQSC, University of São Paulo, - USP, São Carlos, SP, Brazil.
While phosphotellurite glasses have superior properties over SiO-based glasses for many applications in optoelectronics and photonic devices, their high hydroxyl content limits their use in the mid-infrared range. This drawback can be overcome by fluoride addition to the formulation. In this work, we report the preparation, optical, and structural characterization of new glasses in the ternary system TeO-NaF-NaPO having the compositions 0.
View Article and Find Full Text PDFChem Commun (Camb)
March 2022
Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
The synthesis and characterisation of two novel molecular organotelluroxane clusters, comprising of an inorganic TeOX (X = Cl, Br) core structure are described. The integration of highly electron withdrawing 3,5-bis-trifluoromethylphenyl groups to the constituent Te(IV) centres is determined to be crucial in the chalcogen bonding (ChB) halide template directed assembly. Characterised by multi-nuclear H, Te, F NMR, UV-Vis, IR spectroscopies and X-ray crystal structure analysis, the discrete molecular clusters exhibit excellent organic solvent solubility and remarkable chemical stability.
View Article and Find Full Text PDFJ Am Chem Soc
September 2021
Institute of Chemistry, Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation.
Platinum(II) complexes exhibiting an expressed -nucleophilicity of the positively charged metal centers, namely, [Pt(ppy)(acac)] (; acacH is acetylacetone; ppyH is 2-Ph-pyridine) and [Pt(ppy)(tmhd)] (; tmhdH is 2,2,6,6-tetramethylheptanedione-3,5), were cocrystallized with the chalcogen bond donors (4-NCF)Ch (Ch = Se, Te) to form two isostructural cocrystals ·/(4-NCF)Ch, and ·/(4-NCF)Se and ·(4-NCF)Te. The X-ray data for these cocrystals and appropriate theoretical DFT calculations (PBE0-D3BJ) allowed the recognition of the metal-involving chalcogen bond, namely, Ch···-Pt (its energy spans from -7 to -12 kcal/mol). In ·/(4-NCF)Ch, Ch···-Pt bonding is accompanied by the C···-Pt interaction, representing a three-center bifurcate, whereas in ·(4-NCF)Te the chalcogen bond Te···-Pt is purely two-centered and is stronger than that in ·/(4-NCF)Ch because of more efficient orbital overlap.
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