1,721,266 research outputs found
Dataset for Electrodeposition of GeSbTe Based Resistive Switching Memory in Crossbar Arrays
No full textThis dataset is for the paper titled “Electrodeposition of GeSbTe Based Resistive Switching Memory in Crossbar Arrays” with authors Jaafar, Ayoub; Meng, Lingcong; Noori, Yasir; Zhang, Wenjian; Han, Yisong; Beanland, Richard; Smith, David; Reid, Gillian; de Groot, C.H. (Kees); Huang, Ruomeng; Bartlett, Philip to the Journal of Physical Chemistry C. (Manuscript ID: jp-2021-08549r)</span
Macrocyclic and polydentate thio- and seleno-ether ligand complexes of the p-block elements
No full textThe diverse structures exhibited by complexes of p-block (Group 13-15) halides with acyclic and macrocyclic thio-, seleno-, and telluro-ethers are described. Examples range from six-coordinate monomers through to one-, two- or three-dimensional network infinite polymers with structural motifs often very different to those found with d-block elements
Developments in the chemistry of stibine and bismuthine complexes
No full textNew findings in the coordination chemistry of neutral stibine and bismuthine ligands are reviewed. The article describes new ligand syntheses, coordination complexes of d-block and p-block elements with halostibines, halobismuthines, tertiary monostibines, tertiary bismuthines, distibines and hybrid polydentates containing antimony or bismuth. Current views on the nature of the M-Sb(Bi) bonds based upon X-ray structural studies and DFT calculations are discussed. The new work distinguishing metal stibine complexes from the chemistry of lighter phosphorus or arsenic ligands including, µ2- and µ3-bridging stibines, hypervalency and the oxidation of metal-coordinated stibines to stiboranyl or stiborane complexes, is also presented. Emerging applications of metal stibine complexes in catalysis, as reagents for the deposition of electronic materials and as anion sensors are illustrated. Literature coverage is from 2006 - early 2020
Synthesis and structural properties of the first bismuth(III) telluroether complex
No full textThe first donor-acceptor complexes of Sb(III) and Bi(III) with telluroether ligands are reported, together with the crystal structure of [BiBr3(PhTeMe)]
s-Block chalcogenoether chemistry – thio- and selenoether coordination with hard Group 2 ions
No full textA highly unusual series of Group 2 complexes with soft thio- and selenoether coordination, [MI2([18]aneO4E2)] (M = Ca or Sr; E = S or Se), [CaI2([18]aneO2S4)] and [MI2([15]aneO3S2)], has been prepared by reaction of anhydrous MI2 with the macrocycle in dry MeCN solution. The complexes have been characterised via 1H NMR and IR spectroscopy, microanalysis and crystallographic studies which provide unambiguous confirmation of the M–S/Se coordination. The neutral complexes are seven- or eight-coordinate with the iodo ligands cis. The long M–E bond distances of [similar]3.0 Å indicate weak interactions, but they are significantly less than the sum of the van der Waals radii for M and E, and are important in facilitating isolation of the complexes. Trace hydrolysis of [MI2([18]aneO4E2)] and [SrI2([15]aneO3S2)] leads, unexpectedly, to displacement of the iodo ligands rather than the S/Se donor functions, and the resulting dicationic [Ca(H2O)2([18]aneO4S2)]I2, [Sr(H2O)3([18]aneO4S2)]I2·H2O, [Sr(H2O)3([18]aneO4Se2)]I2 and [Sr(H2O)3([15]aneO3S2)]I2 complexes have been structurally characterised, forming eight- and nine-coordinate cations, with all the macrocyclic donor atoms coordinated. Reaction of Ca(CF3SO3)2 with [18]aneO4S2 in anhydrous MeCN solution similarly affords [Ca(CF3SO3)2([18]aneO4S2)], albeit in low yield, also proven crystallographically. Using the MI2 precursors provides a general entry into this area of coordination chemistry of these Group 2 ions, owing in part at least to their higher solubility in the weak donor (weakly competing) MeCN solvent. While CaCl2 reacts with 18-crown-6 either directly in MeCN giving [CaCl2(18-crown-6)], or in the presence of SbCl5 (to form trans-[Ca(MeCN)2(18-crown-6)][SbCl6]2), neither of these routes works with the oxa-thia or oxa-selena crown
Synthesis and properties of [NR<sub>4</sub>]<sub>3</sub>[SbS<sub>4</sub>] (R = Me, Et, n-Pr, n-Bu) and the crystal structures of [N(n-Bu)<sub>4</sub>]<sub>3</sub>[SbS<sub>4</sub>]⋅6H<sub>2</sub>O and [N(n-Bu)<sub>4</sub>]<sub>3</sub>[Sb(S<sub>2</sub>O<sub>3</sub>)<sub>3</sub>]·2THF
No full textThe tetra-alkylammonium tetrathioantimonate(V) salts, [NR4]3[SbS4] (R = Me, Et, n-Pr, n-Bu), have been prepared in basic solution from aqueous [NR4]OH, sulfur and Sb2S3, and characterised by microanalysis, IR, Raman, 1H and 121Sb NMR spectroscopy. The crystal structure of [N(n-Bu)4]3[SbS4]·6H2O shows the presence of the tetrahedral [SbS4]3− anion (disordered over two sites), and also connected through an H-bonding network with the lattice water molecules. The alkylammonium salts are soluble in water and, with the exception of [NMe4]3[SbS4], are also soluble in weakly polar organic solvents, including halocarbons and MeCN. Solubility increases with the R group Me < Et < n-Pr < n-Bu, making the [N(n-Bu)4)3[SbS4] a convenient reagent to explore coordination chemistry or materials applications for which water as the solvent is not suitable. [N(n-Bu)4]3[Sb(S2O3)3]·2THF, the first thiosulfate complex of a p-block element, was produced by slow decomposition of [N(n-Bu)4]3[SbS4] in THF solution in the presence of the [NH(n-Bu)3]Cl (as a source of H+), confirming the instability of the [SbS4]3− anion in acidic media, and the crystal structure of [N(n-Bu)4]3[Sb(S2O3)3]·2THF shows a trigonal antiprismatic coordination geometry with a S3O3 donor set at the antimony(III) centre in the anion.</p
Recent developments in the chemistry of selenoethers and telluroethers
No full textThe synthesis, properties and structures of complexes of mono-, bi-, poly-dentate and macrocyclic seleno- and telluro-ethers with both d-block and p-block elements reported in the last 10 years are described. Sections also describe the synthesis of new polydentate and macrocyclic ligands, the uses of their complexes applications of Se-77- and Te-125-NMR spectroscopy, and current theories of bonding between d-block metals and neutral Group 16 donor ligands
Phosphine and diphosphine complexes of silicon(IV) halides
No full textThe reaction of SiX4 (X = Cl or Br) with PMe3 in anhydrous CH2Cl2 forms trans-[SiX4(PMe3)2], while the diphosphines, Me2P(CH2)2PMe2, Et2P(CH2)2PEt2, and o-C6H4(PMe2)2 form cis-[SiX4(diphosphine)], all containing six-coordinate silicon centers. With Me2PCH2PMe2 the product was trans-[SiCl4(?(1)-Me2PCH2PMe2)2]. The complexes have been characterized by X-ray crystallography, microanalysis, IR, and multinuclear ((1)H, (13)C{(1)H}, and (31)P{(1)H}) NMR spectroscopies. The complexes are stable solids and not significantly dissociated in nondonor solvents, although they are very moisture and oxygen sensitive. This stability conflicts with the predictions of recent density functional theory (DFT) calculations (Wilson et al. Inorg. Chem. 2012, 51, 7657-7668) which suggested six-coordinate silicon phosphines would be unstable, and also contrasts with the failure to isolate complexes with SiF4 (George et al. Dalton Trans. 2011, 40, 1584-1593). No reaction occurred between phosphines and SiI4, or with SiX4 and arsine ligands including AsMe3 and o-C6H4(AsMe2)2. Attempts to make five-coordinate [SiX4(PR3)] using the sterically bulky phosphines, P(t)Bu3, P(i)Pr3, or PCy3 failed, with no apparent reaction occurring, consistent with predictions (Wilson et al. Inorg. Chem. 2012, 51, 7657-7668) that such compounds would be very endothermic, while the large cone angles of the phosphines presumably preclude formation of six-coordination at the small silicon center. The reaction of Si2Cl6 with PMe3 or the diphosphines in CH2Cl2 results in instant disproportionation to the SiCl4 adducts and polychlorosilanes, but from hexane solution very unstable white [Si2Cl6(PMe3)2] and [Si2Cl6(diphosphine)] (diphosphine = Me2P(CH2)2PMe2 or o-C6H4(PMe2)2) precipitate. The reactions of SiHCl3 with PMe3 and Me2P(CH2)2PMe2 also produce the SiCl4 adducts, but using Et2P(CH2)2PEt2, colorless [SiHCl3{Et2P(CH2)2PEt2}] was isolated, which was characterized by an X-ray structure which showed a pseudo-octahedral complex with the Si-H trans to P. Attempts to reduce the silicon(IV) phosphine complexes to silicon(II) were unsuccessful, contrasting with the isolation of stable N-heterocyclic carbene adducts of Si(II
Coordination chemistry and applications of medium/high oxidation state metal and non-metal fluoride and oxide-fluoride complexes with neutral donor ligands
No full textMost high and medium oxidation state (O.S. ≥ 3) metal and non-metal fluorides and oxide fluorides have Lewis acidic properties although detailed exploration of their chemistry with neutral ligands, which differs significantly from that with chloride, bromide or iodide co-ligands, has only been undertaken in recent years. The previous review (Benjamin et. al. Chem. Soc. Rev. 42 (2013) 1460) covered work published up to ~ 2011, and the present article covers new work up to early 2019, a period which has seen many new contributions to the field. This article describes work on the coordination chemistry of d, f and p-block fluorides and oxide fluorides with neutral ligands containing donor atoms drawn from Groups 15 (N, P, As or Sb) and 16 (O, S, Se or Te) and including N-heterocyclic carbenes. The incorporation of the radionuclide 18F into neutral metal complexes and their use in medical diagnosis via positron emission tomography (PET) is described, along with briefer coverage of other potential applications
Coordination complexes of the tungsten(VI) oxide fluorides WOF4 and WO2F2 with neutral oxygen and nitrogen donor ligands
No full textSupplementary NMR and IR spectroscopic data for the paper in Journal of Fluorine chemistry
Coordination complexes of the tungsten(VI) oxide fluorides WOF4 and WO2F2 with neutral oxygen and nitrogen donor ligands
William Levason, Gillian Reid and Wenjian Zhang.
Journal of Fluorine chemistry DOI: 10.1016/j.jfluchem.2016.02.003</span
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