- Unexpected Reactivity of Red Phosphorus in Ionic Liquids
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Red phosphorus is far less reactive than the white allotrope. On the other hand, it is easier to handle and not as toxic as white phosphorus. In the Lewis-acidic ionic liquid (IL) [BMIm]Cl·2AlCl3 ([BMIm] = 1-butyl-3-methylimidazolium), red phosphorus and elemental iodine form several iodides at moderate temperature. 31P liquid- and solid-state NMR spectroscopy was used to rationalize the reaction at various temperatures and ratios of the starting materials. Monitoring of the reaction revealed nanoscale red-phosphorus particles. In addition to this top-down formation, phosphorus nanoparticles were also obtained in a bottom-up synthesis by dissociation of P2I4 in the IL. Depending on the ratio of red phosphorus and iodine, as well as the reaction temperature, P2I4, PI3, or P2I5+ dominate. Red phosphorus readily reacts with iodine in a Lewis-acidic ionic liquid at moderate temperature. Besides iodides, phosphorus nanoparticles are formed. The latter are also obtained in a bottom-up process starting from P2I4. In situ liquid- and solid-state NMR spectroscopy reveals details of the reactions.
- Groh, Matthias F.,Paasch, Silvia,Weiz, Alexander,Ruck, Michael,Brunner, Eike
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- THE PREPARATION AND INFRA-RED SPECTRUM OF TETRAKISTRIIODOPHOSPHINE-NICKEL(0), Ni(PI3)4
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The preparation of tetrakistriodophosphine-nickel(0) as an unstable violet-black solid is reported for the first time.The infrared spectrum is assigned on the basis of the Td molecular point group.
- Edwards, H. G. M.
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- Preparation of stable AsBr4+ and I2As-PI 3+ salts. Why didn't we succeed to prepare AsI 4+ and As2X5+? A combined experimental and theoretical study
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In analogy to our successful PX2+ insertion reactions, an AsX2+ insertion route was explored to obtain new arsenic halogen cations. Two new salts were prepared: AsBr4+[Al(OR)4]-, starting from AsBr3, Br2 and Ag[Al(OR)4], and I 2As-PI3+[Al(OR)]4 from AsI 3, PI3 and Ag[Al(OR)4] (R = C(CF 3)3). The first cation is formally a product of an AsBr2+ insertion into the Br2 molecule and the latter clearly a PI2+ insertion into the As-I bond of the AsI3 molecule. Both compounds were characterized by IR and NMR spectroscopy, the first also by its X-ray structure. Reactions of Ag[Al(OR)4] with AsI3 do not lead to ionization and Agi formation but rather lead to a marginally stable Ag(AsI3)2+[Al(OR)]4 salt. Despite many attempts we failed to prepare other PX-cation analogues such as AsI 4+, As2X5+ and P 4AsX2+ (X = Br, I). To explain these negative results the thermodynamics of the formation of EX2+, EX4+ and E2X5+ (E = As, P; X = Br, I) was carefully analyzed with MP2/TZVPP calculations and inclusion of entropy and solvation effects. We show that As2Br5 + is in very rapid equilibrium with AsBr2+ and AsBr3 (ΔG°(CH2Cl2) = +30 kJ mol -1). The extremely reactive AsBr2+ cation available in the equilibrium accounts for the observed decomposition of the [Al(OR)4]- anion. By contrast, the stability of AsI 3 against Ag[Al(OR)4] appears to be kinetic and, if prepared by a suitable route, As2I5+ would be expected to have a stability intermediate between the known P2I 5+ and P2Br5+. The Royal Society of Chemistry 2005.
- Gonsior, Marcin,Krossing, Ingo
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- Spontaneous growth of uniformly distributed in nanodots and InI3 nanowires on InP induced by a focused ion beam
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We show the growth of hemispherical In nanodots due to differential sputtering by 30 keV gallium (Ga+) ions and of InI3 nanodots and nanowires due to chemical reactions with iodine on the surface of focused ion beam-irradiated areas on a (100)InP substrate. Growth occurs exclusively on previously FIB-fabricated nucleation-sites in the form of craters and trenches. Surface topography and the native oxide on InP are identified as the factors determining the area of growth. Arbitrary 2D patterns can be generated with good control of localization and dimension of the nanostructures. Limitations of size and surface density of the nanodots and nanowires are discussed.
- Callegari, Victor,Nellen, Philipp M.
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- Characterisation of the tetrahalophosphonium cations PBrnI4 - n+ (0 ≤ n ≤ 4) by 31P MAS NMR, IR and Raman spectroscopy and the crystal structures of PI4+AlCl4-, PI4+AlBr4- and PI4+GaI4-
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The novel tetrahalophosphonium salts PBr4+AsF6-, PI4+AlCl4- and PI4+EBr4- (E = Al, Ga) have been synthesised. A variety of solid complexes containing PBr4+ (e.g. PBr4+AsF6-, PBr4+AlBr4- PBr4+GaBr4-), PI4+ (e.g. PI4+AlCl4-, PI4+AlBr4-, PI4+GaBr4-) or the mixed species PBrnI4 - n+ (0 ≤ n ≤ 4, containing AlBr4-, GaBr4-, AsF6- or SbF6-) have been studied by solid-state 31P MAS NMR and vibrational spectroscopy. The influence of the counter-ion on the chemical shift and the vibrational frequencies are discussed. The crystal structures of PI4+AlCl4-, PI4+AlBr4- and PI4+GaI4- are reported. Evidence for the existence of the hitherto unknown mixed bromoiodophosphonium cations PBr3I+, PBr2I2+ and PBrI3+ has been confirmed by spin-orbit corrected density functional calculations of isotropic 31P chemical shifts for PBrnI4 - n+.
- Aubauer,Kaupp,Klapoetke,Noeth,Piotrowski,Schnick,Senker,Suter
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- A niobium-mediated cycle producing phosphorus-rich organic molecules from white phosphorus (P4) through activation, functionalization, and transfer reactions
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(Figure Presented) PROMs: Niobium-mediated aggregation of two molecules of white phosphorus and subsequent exploitation of niobium-phosphorus multiple bonding leads to the synthesis of phosphorus-rich organic molecules as Diels-Alder adducts (see scheme; orange P, white C).
- Cossairt, Brandi M.,Cummins, Christopher C.
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p. 8863 - 8866
(2009/05/30)
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- Reactions of P4 and I2 with Ag[Al(OC(CF3)3)4]: From elusive polyphosphorus cations to subvalent P3I6+ and phosphorus rich P5I2+
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Reactions of X2 (X = Br, I), P4 and Ag(CH2Cl2)[Al(OR)4] [R = C(CF3)3] in suitable ratios to prepare naked polyphosphorus cations were carried out and led to products which sugges
- Krossing, Ingo
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p. 500 - 512
(2007/10/03)
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- P5X2+ (X = Br, I), a phosphorus-rich binary P-X cation with a C2v-symmetric P5 cage
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Insertion of the intermediately formed carbeneanaloguous PX2+ ion (X = Br, I) into one of the P-P bonds of the P4 tetrahedron led to the P5X2+ ion (see structure of the Br derivative)-the first example of the previously unknown class of phosphorus-rich binary P-X cations.
- Krossing,Raabe
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p. 4406 - 4409
(2007/10/03)
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- Destructive or cooperative attack of iodide anions on alkyltriiodophospbonium cations: Elimination of iodine in solution and layer structures in the solid state
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Solid-state and solution 31P NMR shifts of t-BuPI4 and crystal structure determinations of t-BuPI4, i-PrPI4, and MePI4 reveal that alkyltetraiodophosphorus compounds RPI4 (R = t-Bu (1), i-Pr (2), Me3SiCH2 (3), Me (4)) in the solid state involve μ3-bridging I?I interactions between RPI3+ cations and I- anions (leading to the formation of layer structures (2,4) or a 3-dimensional network (1)) whereas, in CS2CD2Cl2 solutions, deiodination by nucleophilic I- anions causes all RPI4 compounds and PI5 to decompose into the iodophosphanes RPI2 or PI3 and molecular iodine. 1 crystallizes in the cubic space group I213, with a = 13.613(2) A?, V = 2522.7(6) A?3, and Z = 8. 2 crystallizes in the monoclinic space group P21/c, with a = 6.686(2) A?, b = 19.918(5) A?, c = 8.961(3) A?, β = 97.41(2)°, V = 1183.4(6) A?3, and Z = 4. 4 crystallizes in the orthorhombic space group Pbcm, with a = 6.031 (2) A?, b = 18.426(7) A?, c = 8.741(5) A?, V = 971.4(3) A?3, and Z = 4. Cation-anion I?I interactions of solid RPI4 are stronger than molecule-ion interactions within the related anion network of solid PhCH2NMe3+HCl4- (5), which crystallizes in the monoclinic space group P21/c, with a = 8.200(1) A?, b = 13.723(1) A?, c = 16.216(1) A?, β = 91.32(2)°, V = 1824.3(3) A?3, and Z = 4.
- Du Mont, Wolf-Walther,Stenzel, Volkmar,Jeske, J?rg,Jones, Peter G.,Sebald, Angelika,Pohl, Siegfried,Saak, Wolfgang,B?tcher, Michael
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p. 1502 - 1505
(2008/10/08)
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- Preparation and spectroscopic characterization of difluorophosphorane, PH3F2. 31P NMR spectrum of protonated diphosphine, P2H5+
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The preparation of difluorophosphorane, PH3F2, from the reaction of diphosphine and hydrogen fluoride is reinvestigated; it has been characterized by multinuclear (1H, 19F, 31P) NMR spectroscopy. Complete infrared and Raman low-temperature spectra of difluorophosphorane are reported. It reacts with alkali-metal fluorides to give phosphine and hexafluorophosphates(V). On the basis of 31P NMR spectroscopic results, a reaction mechanism for the formation of PH3F2 is proposed. The byproducts of the reaction were PH2F3, (PH)n, and P2H5+; the last was observed for the first time. In carbon disulfide solution, diphosphine neither reacts with hydrogen halides to yield protonated diphosphine nor interacts with hydrogen fluoride to form difluorophosphorane.
- Minkwitz, Rolf,Liedtke, Andreas
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p. 4238 - 4242
(2008/10/08)
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