Piperazine Functionalization of C70 for Incorporation into Supramolecular Assemblies

The photochemical reaction of piperazine with C₇₀ produces a mono‐adduct (N(CH₂CH₂)₂NC₇₀) in high yield (67 %) along with three bis‐adducts. These piperazine adducts can combine with various Lewis acids to form crystalline supramolecular aggregates suitable for X‐ray diffraction. The structure of the mono‐adduct was determined from examination of the adduct I₂N(CH₂CH₂)₂NI₂C₇₀ that was formed by reaction of N(CH₂CH₂)₂NC₇₀ with I₂. Crystals of polymeric {Rh₂(O₂CCF₃)₄N(CH₂CH₂)₂NC₇₀}_n?nC₆H₆ that formed from reaction of the mono‐adduct with Rh₂(O₂CCF₃)₄ contain a sinusoidal strand of alternating molecules of N(CH₂CH₂)₂NC₇₀ and Rh₂(O₂CCF₃)₄ connected through Rh?N bonds. Silver nitrate reacts with N(CH₂CH₂)₂NC₇₀ to form black crystals of {(Ag(NO₃))₄(N(CH₂CH₂)₂NC₇₀)₄}_n?7nCH₂Cl₂ that contain parallel, nearly linear chains of alternating (N(CH₂CH₂)₂NC₇₀ molecules and silver ions. Four of these {Ag(NO₃)N(CH₂CH₂)₂NC₇₀}_n chains adopt a structure that resembles a columnar micelle with the ionic silver nitrate portion in the center and the nearly non‐polar C₇₀ cages encircling that core. Of the three bis‐adducts, one was definitively identified through crystallization in the presence of I₂ as ¹²{N(CH₂CH₂)₂N}₂C₇₀ with addends on opposite poles of the C₇₀ cage and a structure with C_2v symmetry. In ¹²{I₂N(CH₂CH₂)₂N}₂C₇₀, individual ¹²{I₂N(CH₂CH₂)₂N}₂C₇₀ units are further connected by secondary I2???N2 interactions to form chains that occur in layers within the crystal. Halogen bond formation between a Lewis base such as a tertiary amine and I₂ is suggested as a method to produce ordered crystals with complex supramolecular structures from substances that are otherwise difficult to crystallize.     

Redox and oxo-abstraction Reactions of Silylamine with MoOCl4

Trimethylsilyldiethylamine Me₃SiNEt₂ and MoOCl₄ (1:1) undergo a free radical redox reaction in CH₂Cl₂ or Et₂O to form MoCl₃O(HNEt₂). Reduction occurs even in aprotic media like CCl₄ and CS₂ to give Mo^V complexes Mo₂Cl₆O₂(N₂Et₄) and Mo₂Cl₆O₂[(SCNEt₂)₂S₂], respectively. A 2:1 reaction in nonionizing protic solvents undergoes redox cum cleavage to provide MoCl₂O(NEt₂) (HNEt₂) but a reaction at reflux temperature in 1,2-dichloroethane leads to diethylammonium salt, [Et₂NH₂][MoCl₄O(HNEt₂)]. Higher molar reactions (3:1, 4:1) in CH₂Cl₂ or Et₂O are associated with redox reaction as well as oxygen atom abstraction to form de-oxo Mo^IV complex MoCl₃(NEt₂)(HNEt₂)₂, whereas, a 3:1 reaction in CS₂ forms Mo₂Cl₄O(S₂CNEt₂)₄. Compounds have been characterized by elemental analyses, redox titration, magnetic moment, conductance, infrared, electronic absorption and ¹H-NMR measurements.     

Synthesis and Application of New Salan Titanium Complexes in the Catalytic Reduction of Aldehydes

Complexes of formula [(H₂N₂O₂)TiCl₂] and [(H₂N₂O₂)Ti(OⁱPr)₂] (H₂N₂O₂H₂ = HOPh’CH₂NH(CH₂)₂NHCH₂Ph’OH, where Ph’ = 2,4-(CMe₂Ph)C₆H₂) were synthesized by the reaction of the salan ligand precursor H₂N₂O₂H₂ with TiCl₄ and Ti(OⁱPr)₄, respectively, in high yields. The dichlorido complex [(H₂N₂O₂)TiCl₂] revealed to be an efficient catalyst for the reduction of benzaldehyde in toluene. Full conversion was observed after 24 h at 55 °C in THF. The same catalyst also converted phenylacetaldehyde and hydrocinnamaldehyde into the corresponding alkanes quantitatively.     

Acetylenic derivatives of metal carbonyls of the triad Fe,Ru, Os—XI Mass spectra of some binuclear complexes

The mass spectra of the following acetylenic derivatives of iron, ruthenium and osmium carbonyls are reported: the iron compounds Fe₂(CO)₆[C₂(C₆H₅)s₂]₂, Fe₂(CO)₆[C₂(CH₃)₂]₂ and Fe₂(CO)₆[C₂(C₂H₅)₂]₂, the ruthenium compounds Ru₂(CO)₆[C₂(C₆H₅)₂]₂, and Ru₂(CO)₆[C₂(CH₃)₂]₂ and the osmium compounds Os₂(CO)₆[C₂(C₆H₅)₂]₂, Os₂(CO)₆[C₂HC₆H₅]₂ and Os₂(CO)₆[C₂(CH₃)₂]₂. Iron compounds exhibit breakdown schemes where binuclear, mononuclear and hydrocarbon ions are present. On the other hand, ruthenium and osmium compounds fragment in a similar way and give rise to singly and doubly charged binuclear ions. Phenylic derivatives of ruthenium and osmium also give weak triply charged ions. The results are discussed in terms of relative strengths of the metal-metal and metal-carbon bonds.     

Kinetics of the thermal decomposition of dinitramide

The kinetic regularities of the heat release during the thermal decomposition of liquid NH₄N(NO₂)₂ at 102.4–138.9 °C were studied. Kinetic data for decomposition of different forms of dinitramide and the influence of water on the rate of decomposition of NH₄N(NO₂)₂ show that the contributions of the decomposition of N(NO₂)₂ ⁻ and HN(NO₂)₂ to the initial decomposition rate of the reaction at temperatures about 100 °C are approximately equal. The decomposition has an autocatalytic character. The analysis of the effect of additives of HNO₃ solutions and the dependence of the autocatalytic reaction rate constant on the gas volume in the system shows that the self-acceleration is due to an increase in the acidity of the NH₄N(NO₂)₂ melt owing to the accumulation of HNO₃ and the corresponding increase in the contribution of the HN(NO₂)₂ decomposition to the overall rate. The self-acceleration ceases due to the accumulation of NO₃ ⁻ ions decreasing the equilibrium concentration of HN(NO₂)₂ in the melt. For Part 2, see Ref. 1. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 395–401 March 1998.     

Synthesis of Inorganic Structural Isomers By Diffusion‐Constrained Self‐Assembly of Designed Precursors: A Novel Type of Isomerism

The structure of precursors is used to control the formation of six possible structural isomers that contain four structural units of PbSe and four structural units of NbSe₂: [(PbSe)_1.14]₄[NbSe₂]₄, [(PbSe)_1.14]₃[NbSe₂]₃[(PbSe)_1.14]₁[NbSe₂]₁, [(PbSe)_1.14]₃[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₂, [(PbSe)_1.14]₂[NbSe₂]₃[(PbSe)_1.14]₂[NbSe₂]₁, [(PbSe)_1.14]₂[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₁[(PbSe)_1.14]₁[NbSe₂]₁, [(PbSe)_1.14]₂[NbSe₂]₁[(PbSe)_1.14]₁[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₁. The electrical properties of these compounds vary with the nanoarchitecture. For each pair of constituents, over 20 000 new compounds, each with a specific nanoarchitecture, are possible with the number of structural units equal to 10 or less. This provides opportunities to systematically correlate structure with properties and hence optimize performance.     

Electrochemical Oxidation of Lithium Carbonate Generates Singlet Oxygen

Solid alkali metal carbonates are universal passivation layer components of intercalation battery materials and common side products in metal‐O₂ batteries, and are believed to form and decompose reversibly in metal‐O₂/CO₂ cells. In these cathodes, Li₂CO₃ decomposes to CO₂ when exposed to potentials above 3.8 V vs. Li/Li⁺. However, O₂ evolution, as would be expected according to the decomposition reaction 2 Li₂CO₃→4 Li⁺+4 e^?+2 CO₂+O₂, is not detected. O atoms are thus unaccounted for, which was previously ascribed to unidentified parasitic reactions. Here, we show that highly reactive singlet oxygen (¹O₂) forms upon oxidizing Li₂CO₃ in an aprotic electrolyte and therefore does not evolve as O₂. These results have substantial implications for the long‐term cyclability of batteries: they underpin the importance of avoiding ¹O₂ in metal‐O₂ batteries, question the possibility of a reversible metal‐O₂/CO₂ battery based on a carbonate discharge product, and help explain the interfacial reactivity of transition‐metal cathodes with residual Li₂CO₃.     

Cobalt-catalyzed dimerization of alkenes

In the presence of CoX₂(PPh₃)₂/3 PPh₃ and zinc metal conjugated alkenes (CH₂CHCOOR, CH₂CHCN, CH₂CHSO₂Ph and CH₂CHCONEt₂) undergo reductive tail-to-tail dimerization to yield the corresponding saturated linear products. Under similar reaction conditions, vinylarenes (ArCHCH₂) give stereoselective head-to-tail dimerization products, trans-1,3-diarylbut-1-ene, in good to excellent yields.     

Polarographic reduction of aqueous sulfur dioxide

Direct- and alternating-current polarograms of aqueous SO₂ · OH₂ solutions show four reduction waves, more than previously reported. Waves I and II probably result from the electroreduction of SO₂ · OH₂ and HSO⁻₃, respectively; these two waves completely overlap at pH 1 but are partially resolved at higher pH values due to different pH dependence. Reduction of SO₂ · OH₂ involves two electrons and two H⁺ ions and the initial product is probably sulfoxylic acid, H₂SO₂. This product can disproportionate to S⁰ and SO₂ · OH₂ in very acidic media (pH ≤ 1) and, in the limit, double the reduction current of SO₂ · OH₂. Reduction of HSO⁻₃ appears to occur via two paths: one is a two-electron three-H⁺ ion path and the other is a one-electron one-H⁺ ion path. The former dominates at pH ≤ 3 and probably produces H₂SO₂; the latter dominates at pH > 4 and may produce SO⁻₂. H₂SO₂ in less acidic media can react with HSO⁻₃ to yield dithionite species (such as H₂S₂O₄, HS₂O⁻₄ and S₂O²⁻₄) and HSO₂ and SO⁻₂ by dissociation of the dithionite species. Waves III and IV are believed to result from reduction of HSO₂ and SO⁻₂, respectively, to H₂SO₂ species.     

Oxidative addition of dialkylphosphites to complexes of iridium(I) and rhodium(I)

The PH bond of dialkylphosphites (dimethylphosphite, 5,5-dimethyl-1,3-dioxa-2-phosphorinane and 4,4,5,5-tetramethyl-1,3-dioxa-2-phospholane) oxidatively adds to irClL₂(L = PPh₃, AsPh₃) and IrCl(PMe₂Ph)₃ generated in situ to give six-coordinate hydrido(dialkylphosphonato)iridium(III) complexes, e.g. IrHClL₂[{(MeO)₂-PO}₂H] and IrHCl(PMe₂Ph)₃[PO(OMe)₂]. Addition of triphenylphosphine to a solution containing [IrCl(C₈H₁₄)₂]₂ and dimethylphosphite in a 1:2 mol ratio gives a five-coordinate hydrido (dimethylphosphonato)iridium(III) complex IrHCl(PPh₃)₂{PO(OMe)₂}, from which six-coordinate pyridine and acetylacetonato complexes IrHCl(PPh₃)₂(C₅H₅N){PO(OMe)₂} and IrH(PPh₃)₂(acac){PO(OMe)₂} can be obtained. The ligand arrangements in the various complexes are inferred from IR, ¹H and ³¹P NMR data.     

Solid‐State Structural Transformations and Photoreactivity of 1D‐Ladder Coordination Polymers of PbII

An attempt has been made to design double‐stranded ladder‐like coordination polymers (CPs) of hemidirected Pb^II. Four CPs, [Pb(μ‐bpe)(O₂C‐C₆H₅)₂] ? 2H₂O ( 1 ), [Pb₂(μ‐bpe)₂(μ‐O₂C‐C₆H₅)₂(O₂C‐C₆H₅)₂] ( 2 ), [Pb₂(μ‐bpe)₂(μ‐O₂C‐p‐Tol)₂(O₂C‐p‐Tol)₂] ? 1.5 H₂O ( 3 ) and [Pb₂(μ‐bpe)₂(μ‐O₂C‐m‐Tol)₂(O₂C‐m‐Tol)₂] ( 4 ) (bpe=1,2‐bis(4′‐pyridyl)ethylene), have been synthesised and investigated for their solid‐state photoreactivity. CPs 2 – 4 , having a parallel orientation of bpe molecules in their ladder structures and being bridged by carboxylates, were found to be photoreactive, whereas CP 1 is a linear one‐dimensional (1D) CP with guest water molecules aggregating to form a hydrogen‐bonded 1D structure. The linear strands of 1 were found to pair up upon eliminating lattice water molecules by heating, which led to the solid‐state structural transformation of photostable linear 1D CP 1 into photoreactive ladder CP 2 . In the construction of the double‐stranded ladder‐like structures, the parallel alignment of C?C bonds in 2 – 4 is dictated by the chelating and μ₂‐η²:η¹ bridging modes of the benzoate and toluate ligands. The role of solvents in the formation of such double‐stranded ladder‐like structures has also been investigated. A single‐crystal‐to‐single‐crystal transformation occurred when 4 was irradiated under UV light to form [Pb₂(rctt‐tpcb)(μ‐O₂C‐m‐Tol)₂(O₂C‐m‐Tol)₂] ( 5 ).     

An ab initio and density functional study of microsolvation of carbon dioxide in water clusters and formation of carbonic acid

Geometry of the CO₂–H₂O complex and reaction barriers leading to the formation of H₂CO₃were studied at the RHF/6-311++G**, MP2/6-311++G**, B3LYP/AUG-cc-pVDZ, B3LYP/AUG-cc-pVTZ, MP2/AUG-cc-pVDZ and CCD/AUG-cc-pVDZ levels of theory. The rotational barrier of the CO₂–H₂O complex and the reaction barrier leading to the formation of H₂CO₃–H₂O from CO₂–(H₂O)₂ were studied using the first three of the above-mentioned methods. Microsolvation of CO₂ in water clusters having upto eight water molecules was studied using the B3LYP/AUG-cc-pVDZ method. Various methods except MP2/AUG-cc-pVDZ predict the equilibrium structure of the CO₂–H₂O complex to be symmetric while the MP2/AUG-cc-pVDZ method predicts it to be unsymmetric. Formation of H₂CO₃ from CO₂–H₂O is strongly catalyzed by the presence of a second water molecule. Atomic orbitals are strongly rehybridized in going from the equilibrium structures of the CO₂–H₂O and CO₂–(H₂O)₂ complexes to the transition states involved in the formation of H₂CO₃ and H₂CO₃–H₂O, respectively, as shown by hybridization displacement charges.     

A study of the selenites of cerium

The solubilities of the systems CeO₂-SeO₂-H₂O and Ce₂O₃-SeO₂-H₂O were studied at 100°C. The field of crystallization of Ce(SeO₃)₂ was established in the system CeO₂-SeO₂-H₂O, and fields of crystallization of Ce₂(SeO₃)₃ and Ce₂(SeO₃)₃H₂SeO₃ were established in the system Ce₂O₃-SeO₂-H₂O. The compound obtained were identified by means of chemical, X-ray and derivatograph analysis. The mechanism of thermal dissociation of Ce(SeO₃)₂, Ce₂(SeO₃)₃ and Ce₂(SeO₃)₃·H₂SeO₃ was studied. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis and Reactivity of New Functionalized Perfluoroalkylfluorophosphates

A new efficient synthesis of functionalized perfluoroalkyl fluorophosphates by oxidative addition of Me₂NCH₂F to the electron‐deficient phosphanes (C₂F₅)_nPF_3?n (n=0–3) is reported. The initially formed zwitterionic, hexacoordinated phosphates [(C₂F₅)_nF_5?nP(CH₂NMe₂?CH₂NMe₂)] are converted into the corresponding phosphonium salts [(Me₃PCH₂NMe₂]⁺[(C₂F₅)_nF_5?nP(CH₂NMe₂)]^? by treatment with PMe₃. In addition [(C₂F₅)₃F₂P(CH₂NMe₂?CH₂NMe₂)] can undergo a 1,3‐methyl shift from the internal to the terminal nitrogen—a structural characterization was achieved from the CF₃ analogue. Reaction of [(C₂F₅)₃F₂P(CH₂NMe?CH₂NMe₃)] and PMe₃ gave rise to the formation of the zwitterionic phosphonium phosphate [(C₂F₅)₃F₂P(CH₂NMe?CH₂PMe₃)], which was fully characterized by X‐ray diffraction analysis. Moreover, an efficient one‐pot synthesis of Cs⁺[(C₂F₅)₃F₂P(CH₂NMe₂)]^? was pursued. This salt turned out to be a useful nucleophile in several alkylation reactions.     

Synthesis,spectroscopic and structural characterisation of vanadium(IV) and oxovanadium(IV) complexes with arsenic donor ligands

The reaction of o-C₆H₄(AsMe₂)₂ with VCl₄ in anhydrous CCl₄ produces orange eight-coordinate [VCl₄{o-C₆H₄(AsMe₂)₂}₂], whilst in CH₂Cl₂ the product is the brown, six-coordinate [VCl₄{o-C₆H₄(AsMe₂)₂}]. In dilute CH₂Cl₂ solution slow decomposition occurs to form the V^III complex [V₂Cl₆{o-C₆H₄(AsMe₂)₂}₂]. Six-coordination is also found in [VCl₄{MeC(CH₂AsMe₂)₃}] and [VCl₄{Et₃As)₂]. Hydrolysis of these complexes occurs readily to form vanadyl (VO²⁺) species, pure samples of which are obtained by reaction of [VOCl₂(thf)₂(H₂O)] with the arsines to form green [VOCl₂{o-C₆H₄(AsMe₂)₂}], [VOCl₂{MeC(CH₂AsMe₂)₃}(H₂O)] and [VOCl₂(Et₃As)₂]. Green [VOCl₂(o-C₆H₄(PMe₂)₂}] is formed from [VOCl₂(thf)₂(H₂O)] and the ligand. The [VOCl₂{o-C₆H₄(PMe₂)₂}] decomposes in thf solution open to air to form the diphosphine dioxide complex [VO{o-C₆H₄(P(O)Me₂)₂}₂(H₂O)]Cl₂, but in contrast, the products formed from similar treatment of [VCl₄{o-C₆H₄(AsMe₂)₂}_x] or [VOCl₂{o-C₆H₄(AsMe₂)₂}] contain the novel arsenic(V) cation [o-C₆H₄(AsMe₂Cl)(μ-O)(AsMe₂)]⁺. X-ray crystal structures are reported for [V₂Cl₆{o-C₆H₄(AsMe₂)₂}₂], [VO(H₂O){o-C₆H₄(P(O)Me₂)₂}₂]Cl₂, [o-C₆H₄(AsMe₂Cl)(μ-O)(AsMe₂)]Cl·[VO(H₂O)₃Cl₂] and powder neutron diffraction data for [VCl₄{o-C₆H₄(AsMe₂)₂}₂].     

Intermediates Involved in the Oxidation of Nitrogen Monoxide: Photochemistry of the cis‐N2O2⋅O2 complex and of sym‐N2O4 in Solid Ne Matrices

Pure sym‐N₂O₄ isolated in solid Ne was obtained by passing cold neon gas over solid N₂O₄ at ?115 °C and quenching the resulting gaseous mixture at 6.3 K. Filtered UV irradiation (260–400 nm) converts sym‐N₂O₄ into trans‐ONONO₂, a weakly interacting (NO₂)₂ radical pair, and traces of the cis‐N₂O₂?O₂ complex. Besides the weakly bound ON?O₂ complex, cis‐N₂O₂?O₂ was also obtained by co‐deposition of NO and O₂ in solid Ne at 6.3 K, and both complexes were characterised by their matrix IR spectra. Concomitantly formed cis‐N₂O₂ dissociated on exposure to filtered IR irradiation (400–8000 cm^?1), and the cis‐N₂O₂?O₂ complex rearranged to sym‐N₂O₄ and trans‐ONONO₂. Experiments using ¹⁸O₂ in place of ¹⁶O₂ revealed a non‐concerted conversion of cis‐N₂O₂?O₂ into these species, and gave access to four selectively di‐¹⁸O‐substituted trans‐ONONO₂ isotopomers. No isotopic scrambling occurred. The IR spectra of sym‐N₂O₄ and of trans‐ONONO₂ in solid Ne were recorded. IR fundamentals of trans‐ONONO₂ were assigned based on experimental ^16/18O isotopic shifts and guided by DFT calculations. Previously reported contradictory measurements on cis‐ and trans‐ONONO₂ are discussed. Dinitroso peroxide, ONOONO, a proposed intermediate in the IR photoinduced rearrangement of cis‐N₂O₂?O₂ to the various N₂O₄ species, was not detected. Its absence in the photolysis products indicates a low barrier (≤10 kJ mol^?1) for its exothermic O? O bond homolysis into a (NO₂)₂ radical pair.     

Thermal decomposition of rhombohedral double carbonates of dolomite type

DTA and TG studies in air were carried out for hydrothermally prepared rhombohedral double carbonates of dolomite type, CaMg(CO₃)₂, CaMn(CO₃)₂, CdMg(CO₃)₂, CdMn(CO₃)₂ and CdZn(CO₃)₂. The solid decomposition products in air have been compared to those obtained under hydrothermal conditions with CO₂ pressure. The dolomite [CaMg(CO₃)₂] decomposes in two stages both in air as well as under high CO₂ pressure. The other carbonates studied, follow a single stage decomposition in air and a two stage decomposition under hydrothermal condition. In air, the manganese containing carbonates CaMn(CO₃)₂ and CdMn(CO₃)₂, decompose to form mixed oxides of CaMnO₃ and CdMnO₃ respectively, while CdMg(CO₃)₂ and CdZn(CO₃)₂ decompose to their respective two mono oxides.

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Zusammenfassung Mittels DTA und TG in Luft werden die hydrothermisch hergestellten rhomboedrischen Doppelkarbonate (Dolomittyp) CaMg(CO₃)₂, CaMn(CO₃)₂, CdMg(CO₃)₂, CdMn(CO₃)₂ und CdZn(CO₃)₂ untersucht. Die in Luft erhaltenen festen Zersetzungsprodukte wurden mit denen verglichen, die unter hydrothermischen Bedingungen mit CO₂-Druck entstehen. Dolomit zersetzt sich sowohl in Luft als auch unter hohem CO₂-Druck in zwei Schritten. Die übrigen untersuchten Karbonate zersetzen sich in Luft in einem, unter hydrothermischen Bedingungen in zwei Schritten. In Luft zersetzen sich die magnesiumhaltigen Karbonate CaMn(CO₃)₂ und CdMn(CO₃)₂ unter Bildung der Mischoxide CaMnO₃ und CdMnO₃, während aus CdMg(CO₃)₂ und CdZn(CO₃)₂ jeweils die entsprechenden beiden Monoxide entstehen.

     

Study of the pyrolysis of H2O2 in the presence of H2and CO by use of UV absorption of HO2

In dissociation experiments of H₂O₂ under shock wave conditions, the spectra of H₂O₂ and HO₂ have been observed in the UV at 2200 ≤ 2800 Å. By the use of these spectra the H₂O₂ decomposition in the presence of H₂ and CO at 870 ≤ T ≤ 1000°K has been analyzed. It was found that in this temperature range, in contrast to low temperature behavior, reactions of H atoms with H₂O₂ and with HO₂ are equally important. The rate of the reaction H + H₂O₂ ← HO₂ + H₂ was estimated in comparison with the rate of the reaction between H and HO₂. Good agreement between calculated and measured concentration profiles of HO₂ and H₂O₂ was obtained.     

Coordination chemistry of bidentate diflourophospines IV. Complexes of 1,2-bis(diflourophosphino)ethane with Ni(O) and Mo(O).

The ligand, 1,2-bis(difluorophosphino)ethane, (PF₂C₂H₄PF₂), reacts with Ni(CO)₄ in the gas phase and in solution to produce carbon monoxide and a polymer, [Ni(PF₂C₂H₄PF₂)₂]_x. PF₂C₂H₄PF₂ displaces norbornadiene from (C₇H₈)Mo(CO)₄ to yield the relatively air-stable complex, Mo(CO)₄-(PF₂C₂H₄PF₂). Analysis of the infrared spectrum of the monomeric complex indicates that the ligand exhibits π-acceptor strength equal to PF₂C₆H₁₀PF₂.     

The Reactivity of Bis(para‐methoxyphenyl)telluroxide towards Triflic Acid and Diphenylphosphinic Acid. Theoretical Considerations of the Protonation and Hydration Process of Diorganotelluroxanes

The reaction of (p‐MeOC₆H₄)₂TeO with two equivalents of HO₃SCF₃ and HO₂PPh₂ provided the tetraorganoditelluroxanes (F₃CSO₃)(p‐MeOC₆H₄)₂TeOTe(p‐MeOC₆H₄)₂(O₃SCF₃) ( 1 ) and (Ph₂PO₂)(p‐MeOC₆H₄)₂TeOTe(p‐MeOC₆H₄)₂(O₂PPh₂)·2 Ph₂PO₂H ( 2 ) in good yields. Compounds 1 and 2 were characterized by solution and solid‐state ³¹P and ¹²⁵Te NMR spectroscopy, IR spectroscopy, electrospray mass spectrometry, conductivity measurements and single crystal X‐ray diffraction. In solution, compound 1 undergoes an electrolytic dissociation and reversibly reacts with traces of water to give the mononuclear cation [(p‐MeOC₆H₄)₂TeOH]⁺ and triflate anions. Theoretical aspects of the protonation and hydration of model telluroxanes R₂TeO (R = H, Me, Ph) were investigated by preliminary DFT calculations and compared to the corresponding selenoxanes R₂SeO. The tellurium dihydroxides R₂Te(OH)₂ seem to be more stable than the hydrogen‐bonded complexes R₂TeO·H₂O.