共查询到20条相似文献,搜索用时 31 毫秒
1.
《International journal of mass spectrometry and ion processes》1989,87(1):13-27
Reactions of platinum metal hexafluoride negative ions were studied by Knudsen cell mass spectrometry. The electron affinities were measured for OsF6(5.93±0.28 eV), IrF6 (6.50±0.38 eV), PtF6(7.00±0.35 eV), and RuF6 (6.47±0.31 eV).The relevant data on electron affinities of platinum metal hexafluorides are discussed. 相似文献
2.
The reactions of PtF5, O2PtF6, PtF6, IrF6, NOPtF6, NO2PtF6, NOIrF6 and NO2IrF6 with NOF and NO2F have been examined under a variety of conditions. The relative ease of synthesis of NOPtF6, (NO)2PtF6, NOIrF6 and NO2IrF6 and the conversion of NOIrF6 to NOPtF6 with PtF6 confirms the order of strong oxidizing properties of PtVIF6, IrVIF6, PtVF-6 and IrVF-6. The NO+2 ion is intrinsically unstable with respect to the elimination of oxygen in Pt (IV) and Ir (IV) fluorometallate salts and accordingly there is serious doubt about earlier claims for the synthesis of the (NO+)(NO+2)PtF6 salt. No evidence for the (NO2)2PtF6 could be found.Raman spectral data for NOBF4, NO2BF4, NO2AsF6, NOPtF6, NO2PtF6, (NO)2PtF6, NOIrF6, NO2IrF6 and (NO)2IrF6 are presented and analyzed. The NO+2 ion appears to be linear in all of the compounds and the absence of the Raman forbidden ν2 fundamental indicates little if any anion-cation interaction at least of the type that leads to a permanent distortion of the cation. In the spectra of all of the nitryl salts, including NO2BF4, a low frequency band at about 140 cm-1 is clearly observed, the intensity and shape of which is a function of the anion. The band probably reflects an unknown lattice dynamic process. No such bands are evident in the spectra of NO+ and (NO+)2 salts. 相似文献
3.
Neil Bartlett 《Angewandte Chemie (International ed. in English)》1968,7(6):433-439
Some of the transition metal hexafluorides demonstrate an astonishing oxidizing power. In particular may be mentioned PtF6, which is capable of oxidizing molecular oxygen or xenon, a process requiring an electron affinity, E(PtF6), > ?156 kcal·mole?1. From a comparative study of all of the hexafluorides of the third transition series the electron affinity is seen to increase regularly in the sequence WF6 < ReF6 < OsF6 < IrF6 < PtF6. The increase in E with unit increase in atomic number of M appears to be ≈ ?20 kcal·mole?1. On the other hand the ability of the hexafluorides to accept F? decreases along this series. This effect enables IrF6 to be more effective than PtF6 in the generation of nitrogen oxide trifluoride, ONF3, by the oxidative fluorination of nitrosyl fluoride, ONF. Both PtF6 and IrF6 interact spontaneously with ONF or O2NF to generate fluorine, at or below room temperature. The decrease in F? -acceptor ability along the series, which stands in sharp contrast to the increase in electron affinity, suggests that ligand crowding increases sharply across the series from WF6 to PtF6. This accords with the observed decrease in molecular volume along the series, both in the hexafluorides and in the MF6? salts. It is clear from this comparison that the species IrF6 and PtF6 are close to a minimum volume for this series. The oxide pentafluorides ReOF5 and OsOF5 are similar in oxidizing ability to their respective hexafluorides but are poorer F? acceptors. Evidently the ligand crowding in MOF5 molecules is greater than in MF6. 相似文献
4.
N.M.R. Measurements on Hexafluorides 19F n.m.r. spectra of natural and 129Xe enriched XeF6, 238UF6, 235UF6, PtF6, IrF6, OsF6 and AuF6? were measured and interpretated. The tetramerisation of XeF6 at low temperatures can be confirmed. 相似文献
5.
Salts containing the ReF6+ ion have been prepared by one-electron oxidation of ReF6 using KrF+ salts. The compounds ReF6+MF6? (M = Au, Sb) are of moderate stability, tending to decompose to ReF7 and the corresponding pentafluoride. This gives rise to isolated ReF7 and MF5 molecules within the ionic lattice, whose presence is demonstrated by Raman spectroscopy. Interaction of ReF6 and PtF6 produced not the salt ReF6+PtF6? (1), but rather the deep red (PtF5)4 when PtF6 was present in excess, and PtF4 when ReF6 was in excess. ReF6 and IrF6 appear to be in equilibrium with ReF7 and (IrF5)4, possibly via an ionic intermediate ReF6+(IrF6·xIrF5)?.The salts ReOF4+MF6? (M = As, Au, Sb) have been characterized. In contrast to the behaviour of IOF5 and IF7, ReOF5 is a better fluoride ion donor than ReF7. 相似文献
6.
Dr. Jianyan Lin Xin Du Prof. Dr. Martin Rahm Dr. Hong Yu Prof. Dr. Haiyang Xu Prof. Dr. Guochun Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(23):9240-9247
Fluorination is a proven method for challenging the limits of chemistry, both structurally and electronically. Here we explore computationally how pressures below 300 GPa affect the fluorination of several transition metals. A plethora of new structural phases are predicted along with the possibility for synthesizing four unobserved compounds: TcF7, CdF3, OsF8, and IrF8. The Ir and Os octaflourides are both predicted to be stable as quasi-molecular phases with an unusual cubic ligand coordination, and both compounds formally correspond to a high oxidation state of +8. Electronic-structure analysis reveals that otherwise unoccupied 6p levels are brought down in energy by the combined effects of pressure and a strong ligand field. The valence expansion of Os and Ir enables ligand-to-metal F 2p→M 6p charge transfer that strengthens M−F bonds and decreases the overall bond polarity. The lower stability of IrF8, and the instability of PtF8 and several other compounds below 300 GPa, is explained by the occupation of M−F antibonding orbitals in octafluorides with a metal-valence-electron count exceeding 8. 相似文献
7.
Jianyan Lin Xin Du Martin Rahm Hong Yu Haiyang Xu Guochun Yang 《Angewandte Chemie (International ed. in English)》2020,59(23):9155-9162
Fluorination is a proven method for challenging the limits of chemistry, both structurally and electronically. Here we explore computationally how pressures below 300 GPa affect the fluorination of several transition metals. A plethora of new structural phases are predicted along with the possibility for synthesizing four unobserved compounds: TcF7, CdF3, OsF8, and IrF8. The Ir and Os octaflourides are both predicted to be stable as quasi‐molecular phases with an unusual cubic ligand coordination, and both compounds formally correspond to a high oxidation state of +8. Electronic‐structure analysis reveals that otherwise unoccupied 6p levels are brought down in energy by the combined effects of pressure and a strong ligand field. The valence expansion of Os and Ir enables ligand‐to‐metal F 2p→M 6p charge transfer that strengthens M?F bonds and decreases the overall bond polarity. The lower stability of IrF8, and the instability of PtF8 and several other compounds below 300 GPa, is explained by the occupation of M?F antibonding orbitals in octafluorides with a metal‐valence‐electron count exceeding 8. 相似文献
8.
The reaction of ozone and gaseous platinum hexafluoride led to O2PtF6(s) and not the desired O3PtF6(s). Suggestions as to why the synthesis of O3PtF6(s) failed are made in terms of the known chemistry of the gaseous O
3
+
cation with O
+
5
proposed as an intermediate. 相似文献
9.
Anton I. Smolentsev Alexander I. Gubanov Andrey M. Danilenko 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):i99-i101
The structures of the hexafluoridoiridates(IV) of calcium, Ca[IrF6]·2H2O [calcium hexafluoridoiridate(IV) dihydrate], strontium, Sr[IrF6]·2H2O [strontium hexafluoridoiridate(IV) dihydrate], and barium, Ba[IrF6] [barium hexafluoridoiridate(IV)], have been determined by single‐crystal X‐ray analysis. The first two compounds are isomorphous. Their metal cations are eight‐coordinated in a distorted square‐antiprismatic coordination environment, and their anions are represented by an almost ideal octahedron. These two structures can be described as frameworks in which all atoms occupy general positions. Sr[RhF6] and Ba[RhF6] have a different space group (, from powder diffraction data) but similar cell dimensions. The structures are very close to that of Ba[IrF6]. The cation is in a cuboctahedral coordination. The metal atoms are located on special positions of symmetry, while the F atoms are in general positions. 相似文献
10.
The hydrolysis reactions of the hexafluorides of molybdenum and tungsten, the pentafluorides of niobium and tantalum and the tetrafluorides of zirconium and hafnium have been studied in liquid hydrogen fluoride. The following new compounds have been isolated and characterized: H3O+WOF-5, H3O+NbF-6 and H3O+TaF-6. Hydrolysis of MoF6 leads to MoOF4, but in HF solution there is evidence for the existence of MoOF-5 ion. 相似文献
11.
Single Crystal Investigations on LiMF6 (M = Rh, Ir), Li2RhF6, and K2IrF6 LiRhF6, LiIrF6, Li2RhF6, and K2IrF6 were obtained again, but for the first time investigated by single crystal X‐ray methods. Rubyred LiRhF6 and yellow LiIrF6 crystallize isostructural in the trigonal space group R3 – C23i (Nr. 148) with the lattice parameters LiRhF6: a = 502.018(7) pm, c = 1355.88(3) pm, Z = 3 and d(Rh–F) = 185.5(1) pm; LiIrF6: a = 506.148(4) pm, c = 1362.60(2) pm, Z = 3, d(Ir–F) = 187.5(3) pm (LiSbF6‐Typ). Yellow Li2RhF6 crystallizes tetragonal in the space group P42/mnm – D144h (Nr. 136) with a = 463.880(8) pm, c = 905.57(2) pm, Z = 2 and d(Rh–F) = 190.3(4)–191.4(3) pm (Trirutil‐Typ). Yellow K2IrF6 crystallizes trigonal in the space group P3m1 – D33d (Nr. 164) with a = 578.88(7) pm, c = 465.06(5) pm, Z = 1 and d(Ir–F) = 194.0(6) pm, isotypic with K2GeF6. 相似文献
12.
This review is composed of six vignettes. They deal with respectively: the reaction of Xe and PtF6; the reaction of O2 and O3 with PtF6; salts of O+, the covalent OF, and noble gas-containing cations; synthesis, reactions and structure of [XeO2]+ en route to [XeF]+ salts; [Xe2]+, green and related species; neutral xenon oxides, nonmetal oxyanions, and a nonmetal fluoride “mid-valence” crisis. Interrelations and interactions are emphasized. 相似文献
13.
The dioxygenyl salts O2MF6 or O2M2F11 where M = As, Sb, Bi, Nb, Ta, Ru, Au, and Pt, were hydrolysed aqueous base (40% NaOH) to evaluate their purity and to gain further information about their thermal instability. Compounds containing As, Sb, Bi, Nb and Ta yielded 1.25 moles O2 per mole of starting material whereas for compounds containing Ru, Au and Pt, 1.5 moles of O2 per mole of salt was produced. The difference is a consequence of the greater oxidizing power of the RuF-6, AuF-6 and PtF-6 anions. All of the dioxygenyl salts are intrinsically unstable at room temperature in vacuum. 相似文献
14.
XAS at the nickel K-edge and UV-visible studies of rhombohedral nickel trifluoride indicate that the compound has a mixed valence composition Ni[NiF6] and is isostructural with Pd[PdF6]. XAS data are reported for NiF2, [NiF6]2–, [NiF6]3–, Pd[PdF6], CoF3 and RhF3 in support of the Ni[NiF6] study. New data from refinements of X-ray powder diffraction of CoF3 and IrF3 are reported in the context of the distortion from hexagonal close packing of rhombohedral trifluorides. 相似文献
15.
A general method for the preparation of many transition metal and actinide oxide tetrafluorides by oxygen-fluorine exchange of their respective hexafluorides using boric oxides is described. This simple procedure affords the preparation of MoOF4, WOF4, ReOF4, OsOF4 and UOF4 in high yield while reaction of boric oxide with IrF6 and RuF6 leads to the preparation of lower fluorides of these elements. The preparation of oxide tetrafluorides by reaction of their oxide tetrachlorides with anhydrous HF has also been investigated, as well as a study of some halogen-exchange reactions of the oxide tetrafluorides. 相似文献
16.
Neil Bartlett 《Journal of fluorine chemistry》2006,127(10):1285-1288
Because electronegativity of an oxidation state is low in an anion, salts of the high oxidation-state species [AgF4]− and [NiF6]2− can be easily made, at 0 °C, in liquid anhydrous HF (aHF) made basic with alkali fluorides. The containers are transparent fluorocarbon, and the F2 is photo-dissociated. The [NiF6]2− salts, and the metastable binary fluorides NiF4 and NiF3, derived from them, are efficient fluorinating agents for the conversion of hydrido compounds to their fully fluorinated relatives. With F2 in aHF made acidic with fluoride-ion acceptors (e.g. MF5, M = As, Sb, Bi) attained oxidation-states are often lower (e.g. AgII, AuII) because of the higher electronegativity in cations. Cationic AgIII and NiIV species (derived from the anions) are sufficiently long-lived, and potent, to generate the most powerfully oxidizing hexafluorides of the second and third transition series (i.e. [MF6], M = Pt, Ru, Rh). This synthesis is especially valuable for RhF6, and has provided for the reinvestigation of the interaction of it with O2. It is proposed that the unexpectedly large unit cell of O2RhF6 is a result of the presence of neutral O2 and neutral RhF6 as well as O2+ and RhF6− in the lattice. 相似文献
17.
Crystal Structures, Vibrational Spectra and Normal Coordinate Analysis of fac ‐(Et4N)[OsF3Cl3] and fac ‐(Et4N)[IrF3Cl3] By careful oxidation of the pure fluorochloroosmates(IV) or ‐iridates(IV) with BrF3 or KBrF4 in dichloromethane the mixed pentavalent complex anions fac‐[OsF3Cl3]– and fac‐[IrF3Cl3]– are formed. X‐ray structure determinations on single crystals have been performed of cis‐(Et4N)[OsF3Cl3] ( 1 ) (orthorhombic, space group Pbca, a = 11.225(5), b = 12.020(5), c = 21.873(5) Å, Z = 8) and fac‐(Et4N)[IrF3Cl3] ( 2 ) (orthorhombic, space group Pbca, a = 11.269(10) b = 12.049(1), c = 21.801(3) Å, Z = 8). Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra for the anion of 1 and 2 have been assigned by normal coordinate analysis. The Osmium compound exhibits slightly higher valence force constants as compared with the Iridium complex: fd(OsF) = 3.25, fd(IrF) = 3.25, fd(OsCl) = 2.35 and fd(IrCl) = 2.25 mdyn/Å. 相似文献
18.
Gene Senges Dr. Lin Li Dr. Artur Wodyński Dr. Helmut Beckers Dr. Robert Müller Prof. Dr. Martin Kaupp Prof. Dr. Sebastian Riedel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(54):13642-13650
Molecular platinum fluorides PtFn, n=1–6, are prepared by two different routes, photo-initiated fluorine elimination from PtF6 embedded in solid noble-gas matrices, and the reaction of elemental fluorine with laser-ablated platinum atoms. IR spectra of the reaction products isolated in rare-gas matrices under cryogenic conditions provide, for the first time, experimental vibrational frequencies of molecular PtF3, PtF4 and PtF5. Photolysis of PtF6 enabled a highly efficient and almost quantitative formation of molecular PtF4, whereas both PtF5 and PtF3 were formed simultaneously by subsequent UV irradiation of PtF4. The vibrational spectra of these molecular platinum fluorides were assigned with the help of one- and two-component quasirelativistic DFT computation to account for scalar relativistic and spin–orbit coupling effects. Competing Jahn-Teller and spin–orbit coupling effects result in a magnetic bistability of PtF4, for which a spin-triplet (3B2g, D2h) coexists with an electronic singlet state (1A1g, D4h) in solid neon matrices. 相似文献
19.
Tony Stüker Xiya Xia Dr. Helmut Beckers Prof. Sebastian Riedel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(45):11693-11700
Pseudo-tetrahedral nitrido trifluorides N≡MF3 (M=Fe, Ru, Os) and square pyramidal nitrido tetrafluorides N≡MF4 (M=Ru, Os) were formed by free-metal-atom reactions with NF3 and subsequently isolated in solid neon at 5 K. Their IR spectra were recorded and analyzed aided by quantum-chemical calculations. For a d2 electron configuration of the N≡MF3 compounds in C3v symmetry, Hund's rule predict a high-spin 3A2 ground state with two parallel spin electrons and two degenerate metal d(δ)-orbitals. The corresponding high-spin 3A2 ground state was, however, only found for N≡FeF3, the first experimentally verified neutral nitrido FeVI species. The valence-isoelectronic N≡RuF3 and N≡OsF3 adopt different angular distorted singlet structures. For N≡RuF3, the triplet 3A2 state is only 5 kJ mol−1 higher in energy than the singlet 1A′ ground state, and the magnetically bistable molecular N≡OsF3 with two distorted near degenerate 1A′ and 3A“ electronic states were experimentally detected at 5 K in solid neon. 相似文献
20.
Ming Wang Jun Chen Wei-fei Fei Zhao-hui Li Ye-peng Yu Xuan Lin Xiao-bin Shan Fu-yi Liu Liu-si Sheng 《化学物理学报(中文版)》2017,30(4):379-388
The photoionization and photodissociation of 1,4-dioxane have been investigated with a reflectron time-of-flight photoionization mass spectrometry and a tunable vacuum ultraviolet synchrotron radiation in the energy region of 8.0-15.5 eV. Parent ion and fragment ions at m/z 88, 87, 58, 57, 45, 44, 43, 41, 31, 30, 29, 28 and 15 are detected under supersonic conditions. The ionization energy of DX as well as the appearance energies of its fragment ions C4H7O2+, C3H6O+, C3H5O+, C2H5O+, C2H4O+, C2H3O+, C3H5+, CH3O+, C2H6+, C2H5+/CHO+, C2H4+ and CH3+ was determined from their photoionization efficiency curves. The optimized structures for the neutrals, cations, transition states and intermediates related to photodissociation of DX are characterized at the B3LYP/6-31+G(d,p) level and their energies are obtained by G3B3 method. Possible dissociative channels of the DX are proposed based on comparison of experimental AE values and theoretical predicted ones. Intramolecular hydrogen migrations are found to be the dominant processes in most of the fragmentation pathways of 1,4-dioxane. 相似文献