- The tellurophosphate K4P8Te4: Phase-change properties, exfoliation, photoluminescence in solution and nanospheres
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We describe the inorganic polymer K4P8Te4 which is soluble, giving solutions that exhibit white emission upon 355 nm laser irradiation. An indirect band gap semiconductor (Eg ≈ 1.4 eV), K4P8/sub
- Chung, In,Song, Jung-Hwan,Kim, Myung Gil,Malliakas, Christos D.,Karst, Angela L.,Freeman, Arthur J.,Weliky, David P.,Kanatzidis, Mercouri G.
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- Metal-free inorganic ligands for colloidal nanocrystals: S2-, HS-, Se2-, HSe-, Te2-, HTe -, TeS32-, OH-, and NH 2- as surface ligands
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All-inorganic colloidal nanocrystals were synthesized by replacing organic capping ligands on chemically synthesized nanocrystals with metal-free inorganic ions such as S2-, HS-, Se2-, HSe-, Te2-, HTe-, TeS32-, OH- and NH2-. These simple ligands adhered to the NC surface and provided colloidal stability in polar solvents. The versatility of such ligand exchange has been demonstrated for various semiconductor and metal nanocrystals of different size and shape. We showed that the key aspects of Pearsons hard and soft acids and bases (HSAB) principle, originally developed for metal coordination compounds, can be applied to the bonding of molecular species to the nanocrystal surface. The use of small inorganic ligands instead of traditional ligands with long hydrocarbon tails facilitated the charge transport between individual nanocrystals and opened up interesting opportunities for device integration of colloidal nanostructures.
- Nag, Angshuman,Kovalenko, Maksym V.,Lee, Jong-Soo,Liu, Wenyong,Spokoyny, Boris,Talapin, Dmitri V.
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- K4Ti3Te9 - A new pseudo one-dimensional polyanionic alkali chalcogenometallate(IV)
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Lustrous black needle shaped single crystals of K4Ti 3Te9 were obtained by reacting K2Te with the corresponding elemental components at 1000°C. K4Ti 3Te9 is monoclinic, mP64, s.g. P21/c (No. 14), Z = 4 with a = 9.052(2), b = 8.088(1), c = 29.465(9) A?, β = 92.35(1)°. The crystal structure was determined from diffractometer data and refined to a conventional R value of 0.035 (2840 Fo's, 146 variables). The compound contains undulating polyanionic chains built up by severely distorted TiTe6 octahedra sharing opposite faces which run parallel to [100] and are arranged in a hexagonal rod packing. The translation period comprises three octahedra. The most striking feature of this compound is the formation of two ditelluride groups per formula unit with unusually long Te-Te distances of 2.960(2) and 3.025(2) A?, respectively. All other Te-Te distances start at 3.2 A?. The nearest homonuclear neighbours of the two pairs are at 3.215(2) and 3.333(2) A? apart. Ti-Te bond lengths range from 2.700(3) to 2.841(3) A? with an average value of 2.772(4) A? for all three crystallographically independent titanium atoms. The alkali cations are irregularly coordinated by 7 to 9 tellurium atoms.
- Kolb, Andreas,Klepp, Kurt O.
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- Synthesis and structural characterization of some selenoruthenates and telluroruthenates
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The reaction of solid [RuClCp(PPh3)2] with TeSe 32- or Sen2- in DMF leads to the formation of [RuCp(PPh3)(μ2-Se2)] 2 (1). In the structure of this compound the two bridging Se 2 groups lead to a six-membered Ru2Se4 ring in a chair conformation. Attached to each Ru center is a PPh3 ligand in an equatorial position and a Cp ring in an axial position. The compound is diamagnetic. The compound [Ru2Cp2(μ3-Se 2)(μ3-Se)]2 (2) is obtained under similar conditions in the presence of air. This structure comprises a centrosymmetric Ru4Se6 dimer formed from the two bridging Se groups and the two bridging Se2 groups. Each Ru center is π-bonded to a Cp ring. The reaction of solid [RuClCp(PPh3)2] with a Te n2- polytelluride solution in DMF leads to the diamagnetic compound [(RuCp-(PPh3))2(μ2-(1,4-η:3,6- η)Te6)] (3). Here the Ru centers are bound to a bridging Te 6 chain at the 1, 4, 3, and 6 positions, leading to a bicyclic Ru2Te6 ring. Each Ru atom is bound to a Cp ring and a PPh3 group. This dimer possesses a center of symmetry. The structure of 3 is the first example of a bicyclic complex where fusion occurs along a Te-Te bond. If the same reaction is carried out in DMF/CH2Cl 2, rather than DMF, then [(RuCp(PPh3))2-(μ2- (1,4-η:3,6-η)Te6)]·CH2Cl2 (4) is obtained. In the solid state it possesses the same Ru2Te6 structural unit as does 3, but the unit lacks a crystallographically imposed center of symmetry. The electronic structures of 3 and 4 have been analyzed with the use of first principles density functional theory. Bond order analysis indicates that the Te-Te bond where fusion occurs has a shared bonding charge of about 2/3 of that found for Te-Te single bonds.
- Dibrov, Sergey M.,Deng, Bin,Ellis, Donald E.,Ibers, James A.
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- Equilibrium among potassium polytellurides in N,N-dimethylformamide solution
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Reactions between elemental potassium and tellurium in N,N- dimethylformamide (DMF) are monitored using UV-visible spectroscopy and compared with those in liquid ammonia solution. In liquid ammonia, the elements react together, via a step-wise sequence, to form polytellurides, each of which is characterized by a distinctive color, the highest being potassium tritelluride. However, when the elements are combined in DMF, these distinctive color changes are not observed - the solution develops an initial plum color, which gradually darkens to purple as the reaction progresses. UV-visible and Raman spectroscopic studies indicate that equilibrium exists among the mono-, di-, and tritelluride in DMF. This equilibrium is not seen in liquid ammonia solution due to the insolubility of potassium monotelluride in that solvent. Spectral data also indicate that potassium tetratelluride is formed in DMF solution.
- McAfee, Jason L.,Andreatta, Jeremy R.,Sevcik, Richard S.,Schultz, Linda D.
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- 1,4-Dichalcogenins: Synthesis from Dichloroethenes and Elemental Chalcogens in a Hydrazine Hydrate–Potassium Hydroxide System
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Abstract: A possibility of the synthesis of 1,4-dichalcogenins by the reaction of vinylidene chloride or 1,2-dichloroethene with elemental chalcogenes in a hydrazine hydrate–KOH system was studied. When vinylidene chloride was used, the maximum yield of 1,4-diselenin was 38%; 1,4-ditellurine was not formed. Diselenin was obtained from 1,2-dichloroethene in 45% yield, while ditellurine was prepared in 21% yield. A plausible mechanism for the formation of dichalcogenin molecules was proposed, which makes it possible to explain the differences in the behavior of 1,1- and 1,2-dichloroethenes in the reaction with potassium telluride. When two chalcogenes were introduced into the reaction, 1,4-dichalcogenins with different chalcogen atoms were obtained with yields of up to 7%.
- Bogdanova, I. N.,Grabelnykh, V. A.,Istomina, N. V.,Korchevin, N. A.,Nikonova, V. S.,Rozentsveig, I. B.,Russavskaya, N. B.,Sosnovskaya, N. G.
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p. 814 - 819
(2021/06/26)
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- Smallest molecular chalcogenidometalate anions of the heaviest metals: Syntheses, structures, and their interconversion
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The syntheses of the first molecular meta-selenidomercurate(ii), ortho-telluridothallate(iii) and a hydrate of an ortho-selenidoplubate(iv) are presented alongside an improved and facile synthesis of the selenidobismuthate(iii) with almost quantitative yields. By means of quantum chemical calculations, the energetics of the interconversions of small metalate anions is discussed and the existence of the heaviest homologues of [NO2]-, [NO3]-, [PO4]2- and [CO3]2- are predicted.
- Thiele,Donsbach,Riedel,Marsch,Harms,Dehnen
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p. 5958 - 5967
(2016/04/26)
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- Novel route to the synthesis of chalcogenolanes, chalcogenanes, and 1,2-dichalcogenaepanes
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The saturated heterocyclic compounds C4H8Y, C 5H10Y, and C5H10Y2 (Y = Se or Te) have been prepared by the reaction of 1,4-dibromobutane or 1,5-dibromopentane with potassium chalcogenides. The novelty of the route consists of the use of the hydrazine hydrate-KOH system for the reductive generation of potassium selenide, telluride, diselenide or ditelluride from elemental chalcogens.
- Levanova,Grabel'Nykh,Elaev,Russavskaya,Klyba,Albanov,Korchevin
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p. 1345 - 1352
(2014/07/21)
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- The synthesis and crystal structure of K2UTe3
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Syntheses of K2UTe3 were performed via polytelluride fluxes from K2Te3 and metallic uranium in the molar ratio 2:1 at 600 to 800 °C. Well-formed crystals were isolated by washing the reguli with liquid ammonia. One-phase powder samples of K2UTe3 are also available by reactions of stoichiometric mixtures of K2Te3 and uranium. K2Te3 was prepared in liquid ammonia from the elements using a glass apparatus specially designed for the synthesis of alkali metal chalcogenides. By x-ray structure analyses of single crystals we found K2UTe3 to crystallize monoclinic (space group C2/m, Z = 4) with the lattice parameters a = 800.41(3) pm, b = 1387.67(5) pm, c = 851.63(4) pm and β = 108.495(3)°. The crystal structure of the compound may be regarded as a stuffed AlCl3-type structure. The existence of an analogous compound Rb2UTe3 crystallizing isotypically to K2UTe3 has been shown by x-ray powder investigations.
- Sto?we, Klaus,Appel-Colbus, Stephan
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p. 1647 - 1651
(2008/10/08)
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- Complex chalcogenides of the IVa metals with low dimensional anionic partial structures. Preparation and crystal structures of K2ZrTe3 and Rb2ZrTe3
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The isostructural compounds K2ZrTe3 and Rb2ZrTe3 were obtained at 1000°C by reacting K2Te and Rb2Te with stoichiometric amounts of Zr and Te. The compounds are monoclinic, mP24, space group P21/c, Z = 4 with a = 9.089(3), b = 14.148(4), c = 6.986(3)A, β = 105.90(1)° and a = 9.735(4), b = 14.300(7), c = 6.952(8) A, β = 108.61(2)°, respectively. The crystal structure was determined from diffractometer data and refined to R = 0.030 for 1452 Fo's for K2ZrTe3 and R = 0.038 for 1131 Fo's for Rb2ZrTe3. The crystal structure is of a new type, characterized by infinite anionic chains, 1∞ -[ZrTe3]2- built up by octahedra sharing opposite faces which run along [001]. The mean Zr-Te bond lengths are 2.921 and 2.920 A, respectively. The alkali cations separating the chains are characterized by two different - distorted octahedral and pentagonal bipyramidal - chalcogen environments.
- Klepp, Kurt O.,Kolb, Andreas
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p. 441 - 446
(2007/10/03)
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- Syntheses and solid-state NMR of n-Bu4NTeH, Me4NSeH, and (Me4N)2Te2 and X-ray crystal structures of Me4NSeH and (Me4N)2Te2
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The syntheses of n-Bu4NTeH, Me4NSeH, and (Me4N)2Te2 are described. The compounds have been characterized by 123Te, 125Te, and 77Se solid-state NMR spectroscopy and by 125Te M?ssbauer spectroscopy. The X-ray crystal structures of Me4NSeH and (Me4N)2Te2 are reported and some structural data for n-Bu4NTeH are given. For Me4NSeH: tetragonal space group P4/nmm, Z = 2, a = 7.8855(8) ?, c = 5.6484(5) ?, V = 351.22 ?3, RF = 0.020 for 180 data with Io ≥ 2.5σ(Io); isostructural with Me4NBr. For (Me4N)2Te2: cubic space group Pa3, Z = 4, a = 11.499(1) ?, V = 1520.5 ?3, RF = 0.018 for 454 data with Io ≥ 2.5σ(Io); the ionic packing is of the anti-fluorite type.
- Batchelor,Einstein,Gay,Jones,Sharma
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p. 4378 - 4383
(2008/10/08)
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- Synthesis of alkali metal tellurides and ditellurides in THF and their relative reactivities towards alkyl bromides: A convenient synthesis of dialkyl tellurides and dialkyl ditellurides
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Lithium, sodium and potassium reduce smoothly elemental tellurium to telluride (Te2-) and ditelluride (Te22-) anions in the tetrahydrofuran, THF, medium in the presence of catalytic amounts of naphthalene.The relative reactivities of these alkali metal tellurides towards alkyl bromides have been investigated and a number of dialkyl tellurides and dialkyl ditellurides prepared in good to excellent yields.The compounds prepared are characterised by elemental analysis, 1H NMR and mass spectral studies.
- Bhasin, K K,Gupta, Vijay,Sharma, R P
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p. 632 - 634
(2007/10/02)
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- Homo- and heteropolychalcogenide anions Ch2-, HCh-, Ch22-, Ch32-, and Ch42- (Ch = Se and/or Te): Solution 1H, 77Se, 123Te, and 12
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The homo- and heteropolychalcogenide anions, Chn2- (n = 1, 2, 3, 4; Ch = Se and/or Te) and the hydrochalcogenide anions, HCh-, have been prepared and characterized in solution by 1H, 77Se, 123/s
- Bj?rgvinsson, Már,Schrobilgen, Gary J.
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p. 2540 - 2547
(2008/10/08)
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