Iodine Fluoride Research Articles

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides.

The ability to investigate hypervalent iodine(V) fluorides has been limited primarily by their difficult preparation traditionally using harsh fluorinating reagents such as trifluoromethyl hypofluorite and bromine trifluoride. Here, we report a mild and efficient route using Selectfluor to deliver hypervalent iodine(V) fluorides in good isolated yields (72-90%). Stability studies revealed that bicyclic difluoro(aryl)-λ5-iodane 6 was much more stable in acetonitrile-d 3 than in chloroform-d 1, presumably due to acetonitrile coordinating to the iodine(V) centre and stabilising it via halogen bonding.

A hypervalent and cubically coordinated molecular phase of IF8 predicted at high pressure.

Up to now, the maximum coordination number of iodine is seven in neutral iodine heptafluoride (IF7) and eight in anionic octafluoride (IF8 -). Here, we explore pressure as a method for realizing new hypercoordinated iodine compounds. First-principles swarm structure calculations have been used to predict the high-pressure and T → 0 K phase diagram of binary iodine fluorides. The investigated compounds are predicted to undergo complex structural phase transitions under high pressure, accompanied by various semiconductor to metal transitions. The pressure induced formation of a neutral octafluoride compound, IF8, consisting of eight-coordinated iodine is one of several unprecedented predicted structures. In sharp contrast to the square antiprismatic structure in IF8 -, IF8, which is dynamically unstable under atmospheric conditions, is stable and adopts a quasi-cube molecular configuration with R3[combining macron] symmetry at 300 GPa. The metallicity of IF8 originates from a hole in the fluorine 2p-bands that dominate the Fermi surface. The highly unusual coordination sphere in IF8 at 300 GPa is a consequence of the 5d levels of iodine coming down and becoming part of the valence, where they mix with iodine's 5s and 5p levels and engage in chemical bonding. The valence expansion of iodine under pressure effectively makes IF8 not only hypercoordinated, but also hypervalent.

ChemInform Abstract: Structure and Heats of Formation of Iodine Fluorides and the Respective Closed‐Shell Ions from CCSD(T) Electronic Structure Calculations and Reliable Prediction of the Steric Activity of the Free‐Valence Electron Pair in ClF6‐, BrF6‐, and IF6‐

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Structure and Heats of Formation of Iodine Fluorides and the Respective Closed-Shell Ions from CCSD(T) Electronic Structure Calculations and Reliable Prediction of the Steric Activity of the Free-Valence Electron Pair in ClF6−, BrF6−, and IF6−

Atomization energies at 0 K and heats of formation at 0 and 298 K are predicted for IF, IF2-, IF2+, IF3, IF4-, IF4+, IF5, IF6-, IF6+, IF7, IF8-, BrF6-, and ClF6- from coupled cluster theory [CCSD(T)] calculations with effective-core potential correlation-consistent basis sets for I. In order to achieve near chemical accuracy (+/-1 kcal/mol), three corrections were added to the complete basis set binding energies based on frozen-core coupled-cluster theory energies: a correction for core-valence effects, a correction for scalar relativistic effects, and a correction for first-order atomic spin-orbit effects. Vibrational zero-point energies were computed at the coupled-cluster level of theory except for IF6-, IF7, and IF8-. The calculated heats of formation for the neutral and ionic IFn fluorides were used to predict fluoride affinities. It is shown that high-level calculations are required to predict correctly the steric activity of the free-valence electron pair on the central atoms in IF6- (C3v), BrF6- (Oh), and ClF6- (Oh ). The vibrational spectrum of IF8- was reanalyzed, and complete mode descriptions for square-antiprismatic XF8 species of D4d symmetry are given.

Solid-state 19F and 13C NMR of room temperature fluorinated graphite and samples thermally treated under fluorine: Low-field and high-resolution studies

Room temperature graphite fluorides consisting of raw material and samples post-treated in pure fluorine atmosphere in the temperature range 100–500 °C have been studied by solid-state NMR. Several NMR approaches have been used, both high and low-field 19F, 19F MAS and 13C MAS with 19F to 13C cross polarization. The modifications, in the graphitic lattice, of the catalytic iodine fluorides products have been examined. A transformation of the C–F bond character from semi-ionic to covalent has been found to occur at a post-treatment temperature close to 400 °C. It is shown that covalency increases with temperature.

Advances in the Preparation of Organofluorine Compounds Involving Iodine and/or Iodo‐Compounds

AbstractFor Abstract see ChemInform Abstract in Full Text.

NMR and EPR studies of room temperature highly fluorinated graphite heat-treated under fluorine atmosphere

Semi-ionic carbon fluoride obtained by reaction of graphite with a gaseous mixture of IF5, HF and F2 was modified by a post-fluorination at various temperatures in the range 100–680 °C. The resulting materials were studied by 19F-NMR and EPR both at room temperature and at different experimental temperatures from 200 to 360 K and from 100 to 473 K for NMR and EPR experiments, respectively. 19F-NMR gives information about the residual intercalated iodine fluoride species (IF5, IF6− and IF7) such as the temperature of their removal from the host fluorocarbon matrix and their mobility into the interlayer space. The nature of the C–F bonding was investigated by 19F-NMR, MAS/13C-NMR, FT-IR spectroscopy and X-ray diffraction. The C–F bonding changes from semi-ionic to a mainly covalent character at a fluorination post-treatment temperature close to 450 °C. This transformation coincides with the removal of the iodine fluoride species from the host structure. The densities of the paramagnetic dangling bonds were studied by EPR; this technique allows also to investigate the local environment of the dangling bonds in the fully fluorinated samples (obtained with fluorination post-treatment temperatures higher than 450 °C). As a matter of fact, an hyperfine structure was observed for these samples; it results from interaction of the dangling bond electron with six neighboring fluorine nuclei. The role of the intercalated species (iodine fluoride compounds and HF) on the mechanisms of the extra-fluorination is also discussed.

Synthesis, characterization, and computational study of the trans-IO2F5(2-) anion.

The combination of CH(3)CN solutions of [N(CH(3))(4)][F] and a mixture of cis- and trans-[N(CH(3))(4)][IO(2)F(4)] produces the novel trans-IO(2)F(5)(2)(-) anion. Under the given conditions, only the trans-IO(2)F(4)(-) anion acts as a fluoride ion acceptor, thus allowing the separation of isomerically pure, soluble cis-IO(2)F(4)(-) from insoluble trans-IO(2)F(5)(2)(-). The trans-IO(2)F(5)(2)(-) and cis-IO(2)F(4)(-) anions were characterized by infrared and Raman spectroscopy and theoretical calculations at the LDFT and HF levels of theory. The trans-IO(2)F(5)(2)(-) anion has a pentagonal-bipyramidal geometry with the two oxygen atoms occupying the axial positions. It represents the first example of a heptacoordinated main group AO(2)X(5) species and completes the series of pentagonal-bipyramidal iodine fluoride and oxide fluoride species. The geometries of the pentagonal-bipyramidal series IO(2)F(5)(2)(-), IOF(5)(2)(-), IF(5)(2)(-), IOF(6)(-), IF(6)(-), and IF(7) and the corresponding octahedral series IO(2)F(4)(-), IOF(4)(-), IF(4)(-), IOF(5), IF(5), and IF(6)(+) were calculated by identical methods. It is shown how the ionic charge, the oxidation state of the iodine atom, the coordination number, and the replacement of fluorine ligands by either an oxygen ligand or a free valence electron pair influence the stuctures and bonding of these species.

A Simple Method for the Displacement of Bromine by Fluorine at Tertiary, Benzylic or Non‐Classical Secondary Sites.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A simple method for the displacement of bromine by fluorine at tertiary, benzylic or non-classical secondary sites

Iodine fluoride or, being its operational equivalent, the mixture of N-iodosuccinimide and triethylamine tris(hydrogen fluoride) reacts with tertiary and benzylic bromoalkanes to afford the respective fluoroalkanes in moderate-to-excellent yields. In contrast, primary bromoalkanes are virtually inert under identical conditions. Secondary bromoalkanes do not react either unless the heterolytically generated cationic intermediates benefit from non-classical resonance stabilization.

Thermochemistry of some mono-substituted iodine fluorides and a comparison of gas and solid phase structures

The heat of formation of iodine trifluoride, obtained from an ab initio calculation of its heat of dismutation to mono- and penta-fluorides, was close to their average value. The mean bond dissociation energies of these iodine fluorides is almost invariant. The reduction couples between penta and trifluoro, or tri and mono-fluoro compounds, were employed to calculate formation heats of phenyl and trifluoromethyl iodine fluorides via similar isodesmic reactions. The substituted derivatives were stronger oxidants than the unsubstituted iodine fluorides as quantified by their redox couples. Similarly the corresponding chloro-fluorides were stronger oxidants than the iodo-fluorides. Heats of formation of other iodine fluoride derivatives can be obtained by additivity methods. Recent X-ray structures, when compared with calculated gas-phase structures, showed a lesser tilt of axial I-F bonds to the vertical in the solids probably due to intermolecular association. Rotational barriers around C-I bonds were small enough to permit almost free rotation at ambient temperatures.

Low-temperature carbon fluoride for high power density lithium primary batteries

Quantitative fluorination of graphite has been achieved at ambient temperature by the preliminary intercalation of iodine fluoride in HF + F 2 atmosphere. This fluorinated graphite LT-CF x was used as the cathode material in liquid electrolyte lithium cells; rate capability tests were carried out. Results are presented in comparison with those obtained with conventional HT-CF x . An outstanding behavior with LT-CF x is found, especially at high rate.

ChemInform Abstract: Stereochemistry of Iodine(V) and Tellurium(IV) Fluoride Compounds with an Unshared Electron Pair

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis and Antiviral Activity of 3-Fluorocarbocyclic Oxetanocin A.

A new procedure for the synthesis of 3'-fluorocarbocyclic oxetanocin A (1b) was developed. Addition of iodine fluoride to O-cyclohexylidene-cis-2-hydroxymethyl-3-methylene-1-cyclobutanol (4) afforded O-cyclohexylidene-(1S*,2S*,3R*)-3-fluoro-3-iodomethyl-2- hydroxymethyl-1-cyclobutanol (5) and the undesired (1S*,2S*,3S*)-isomer (6) in 6.2% and 38% yields, respectively. When fluorine was introduced into the carbocycle after condensation of 6-chloropurine, 6-chloro-9-[(1R*,2S*,3R*)-3-fluoro-3-iodomethyl-2- (trityloxymethyl)cyclobutyl]purine (10) was obtained as a sole addition product, which was readily converted to 1b. This compound (1b) exhibited a broad spectrum of antiviral activity, especially against human cytomegalovirus.

On the structure of IOF5 [iodine fluoride oxide

Ab initio and density functional theory calculations were carried out for IOF 5 and, together with experimental and ab initio data for isoelectronic TeOF 5 - suggest that the axial and the equatorial I-F bonds of IOF 5 are of comparable lengths and that the O-I-F eq bond angle is close to 97.2 o . Using these two constraints and the previously published I 16 OF 5 and I 18 OF 5 microwave data, the structure of IOF 5 was determined as rI-O=1.725 A, rI-F ax ≡rI-F eq =1.826 A, and OIF eq =9.72 o

Quenching reactions of fluoroimidogen (a1.DELTA.) by chlorine, fluorine chloride, bromine, iodine chloride, iodine fluoride and iodine

The reactions of NF(a 1 Δ) with the molecular halogens (X 2 ) and inter-halogens (XY) have been studied in a flow reactorat 300 K. Observation of the rate of removal of NF(a) by X 2 gives the total quenching rate constants, which increase in the order listed on the title, to a value of 15×10 -11 cm 3 s -1 for I 2

New organoiodine(III)-fluorine compounds

Besides IF 3 no binary iodine(III) oxide or ternary iodine(III) fluoride oxide is known. Now we report on the preparation of an organoiodine(III) fluoride oxide: C 6F 5I(F)OI(F)C 6F 5 ( I). I is prepared by well-aimed fluorine-oxygen — metathesis on C 6F 5IF 2. Another new class of iodine(III) compounds are salts with the aryliodine(III)fluoride cation [ RIF] + ( II). The cation II is also obtained from aryliodine(III)difluorides. It has got a strong electrophilic character and allows e.g. electrophilic substitution-reactions on aromatic compounds under formation of asymmetric diaryliodonium-cations: ▪ With hard bases II reacted spontaneously, e.g. with F − the neutral educt molecule RIF 2 is obtained. Furthermore we report an alternative method to the already known preparative routes for C 6F 5 IF 2 . The advantage of the new way is the purity of the product. For the first time a correct melting-point and decomposition-temperature for C 6F 5 IF 2 is reported.

Excitation of iodine fluoride(B3.PI.(0+)) by metastable oxygen. 1. Studies involving iodine fluoride (X,v)

Excitation of iodine fluoride(B3.PI.(0+)) by metastable oxygen. 1. Studies involving iodine fluoride (X,v)

Further observations on the excitation of iodine fluoride (B3.PI.0+) in active nitrogen

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFurther observations on the excitation of iodine fluoride (B3.PI.0+) in active nitrogenLawrence G. PiperCite this: J. Phys. Chem. 1991, 95, 10, 3965–3967Publication Date (Print):May 1, 1991Publication History Published online1 May 2002Published inissue 1 May 1991https://doi.org/10.1021/j100163a015RIGHTS & PERMISSIONSArticle Views18Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts

Emission spectra of iodine fluoride from a corona-excited supersonic jet discharge

High-resolution emission spectra of IF from a corona-excited supersonic jet discharge are presented. Six vibrational bands of the D'2-A'2 transition were rotationally analyzed for the first time, as well as four bands of the EO + -XO + transition. A study of the Ω-type doubling observed for the high-J rotational levels of D' has provided estimates for the relative energy differences between the electronic origins of the first-tier ion-pair states