Iodine Monofluoride Research Articles

Cooperative strengthening of the halogen bond in cyclic clusters of iodine monofluoride, (IF)n (n = 3–8): From a closed-shell interaction, F-I…F, to a symmetric partly covalent interaction, F…I…F

Cooperativity in cyclic (IF)nclusters, n = 3–8, is investigated using ab initio and density functional methods. Trimer formation weakens the halogen bond while larger cluster formation strengthens it substantially. Topological analysis reveals a change in the nature of the interaction from a closed-shell interaction (n ≤ 4) to a partly covalent interaction (n ≥ 5). For clusters of size n < 6, multiple iodonium ion transfer occurs via a concerted mechanism. At the CCSD(T) level, the barrier height for the multiple ion transfer decreases from 40.41 kcal/mol in the trimer to just 0.10 kcal/mol in the pentamer.

Two-dimensional iodine-monofluoride epitaxy on WSe2

Interhalogen compounds (IHCs) are extremely reactive molecules used for halogenation, catalyst, selective etchant, and surface modification. Most of the IHCs are unstable at room temperature especially for the iodine-monofluoride (IF) whose structure is still unknown. Here we demonstrate an unambiguous observation of two-dimensional (2D) IF bilayer grown on the surface of WSe2 by using scanning transmission electron microscopy and electron energy loss spectroscopy. The bilayer IF shows a clear hexagonal lattice and robust epitaxial relationship with the WSe2 substrate. Despite the IF is known to sublimate at −14 °C and has never found as a solid form in the ambient condition, but surprisingly it is found stabilized on a suitable substrate and the stabilized structure is supported by a density functional theory. This 2D form of IHC is actually a byproduct during a chemical vapor deposition growth of WSe2 in the presence of alkali metal halides as a growth promoter and requires immediate surface passivation to sustain. This work points out a great possibility to produce 2D structures that are unexpected to be crystallized or cannot be obtained by a simple exfoliation but can be grown only on a certain substrate.

Crystal structure and properties of iodine monofluoride compounds at high pressure

The pressure-induced structural phase transitions of halogen compound IF under high pressure were studied by using the unbiased CALYPSO structure prediction method. The phase transition sequence of IF under high pressure is determined to be P1 → P21/c-I → P21/c-II → I4/mmm, and the corresponding phase transition pressures are 3 GPa, 16.5 GPa and 46 GPa, respectively. The physical properties of each predicted phase were thus fully studied, and it was found that the P1 phase was unstable which is in excellent agreement with the experiment result. Furthermore, our exploration of the high pressure phases for IF will provide fundamental insights for further exploration the structural phase transition of other halogen compounds under high pressure.

ChemInform Abstract: Iodine and Its Interhalogen Compounds: Versatile Reagents in Carbohydrate Chemistry. Part 25. A Facile and Convenient Synthesis of Disarmed Glycosyl Fluorides Using in situ Generated Iodine Monofluoride.

AbstractVarious thioglycosides are investigated to yield the α‐anomeric glycosyl fluorides exclusively.

A facile and convenient synthesis of disarmed glycosyl fluorides using in situ-generated iodine monofluoride (see Ref. 1)

A facile and convenient synthesis of disarmed glycosyl fluorides using in situ-generated iodine monofluoride is reported. The method is tolerant to most of the popularly used protecting groups and gives exclusively the α-anomeric product in very good yields.

IPy2BF4/HF-Pyridine: A New Combination of Reagents for the Transformation of Partially Unprotected Thioglycosides and n-Pentenyl Glycosides to Glycosyl Fluorides

The combination of bis(pyridinium)iodonium (I) tetrafluoroborate (IPy2BF4), and hydrogen fluoride pyridine (HF-py) forms an iodine monofluoride (IF) synthetic equivalent that can be used in the preparation of partially unprotected glycosyl fluorides from partially unprotected n-pentenyl glycosides and thioglycosides, thus avoiding the need for the protection/deprotection steps normally required in that transformation.

Chemical generation of iodine atoms

Abstract The chemical generation of atomic iodine using a chemical combustor to generate the atomic fluorine intermediate, from the reaction of F2 + H2, followed by the production of atomic iodine, from the reaction of F + HI, was investigated. The maximum conversion efficiency of HI into atomic iodine was observed to be approximately 75%, which is in good agreement with the theoretical model. The conversion efficiency is limited by the formation of iodine monofluoride at the walls of the combustor where the gas phase temperature is insufficient to dissociate the IF.

ChemInform Abstract: A Mild Method for Introducing Iodine Monofluoride into Alkenes and Iodination of Aromatics Using Xenon Difluoride.

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.

A mild method for introducing iodine monofluoride into alkenes and iodination of aromatics using xenon difluoride

Reaction of xenon difluoride (XeF 2) and iodine (I 2) or N-iodosuccinimide (NIS) with alkenes gives iodofluoro products in good yields. Aromatics react with XeF 2 and I 2 or NIS to undergo electrophilic aromatic iodination. Iodine monofluoride (IF) generated from XeF 2 is less reactive than IF generated from I 2 and fluorine gas. This difference in reactivity suggests that the interhalogen IF is delivered to the alkene or aromatic from a complex with XeF 2.

Hyperfine constants of bromine and iodine monofluoride

The J′−J″=1−0 rotational transitions of 79BrF, 81BrF, and IF have been reinvestigated in the ground and first excited vibrational states using microwave Fourier transform spectroscopy. For IF, lines were also detected in the second excited vibrational state. Bromine and iodine nuclear quadrupole coupling constants, spin–rotation constants for all nuclei, and tensor and scalar spin–spin coupling constants (S and J), have been determined along with the rotational constants. Antishielding occurs at the fluorine nucleus for both BrF and IF, as has been found earlier for ClF. The antishielding has been rationalized following a model developed for ClF. The ratio 1.197 0514 (32) has been found for the equilibrium bromine quadrupole coupling constants of 79/81BrF.

Preparation of [NEt 4][IF 2] by the reaction of IF with [NEt 4

Tetraethylammonium difluoroiodate(I), [NEt 4][IF 2], is prepared by direct reaction of iodine monofluoride and tetraethylammonium fluoride. 19F NMR, IR and Raman spectra are described. The spectroscopic data are consistent with D ∞ h symmetry of the anion.

Reactivity of iodine monofluoride on sub-micromolar scale with arenes

In situ generated iodine monofluoride (IF) has for the first time been used on sub-micromolar scale for iodination of model arenes. Reactivity and selectivity of the reagent have been determined by the radiotracer method using [ 123,131I]IF.

Conversion of the carbonyl group to CF2 using iodine monofluoride (IF)

Conversion of the carbonyl group to CF2 using iodine monofluoride (IF)

Iodine monofluoride discharge laser investigation

The results of an experimental investigation to improve the performance of a discharge-pumped iodine monofluoride laser are reported. Lasing was observed at 478.7, 484.7, 490.7, and 496.5 nm. Electrical measurements of the discharge characteristics permitted the energy flow in the circuit to be followed and laser efficiencies to be calculated. Parametric studies of gas mixtures were carried out. By optimizing several parameters, single-pulse lasing energies greater than 50 mJ were obtained.

Nitrogen Triiodide

Deep‐red, adduct‐free NI3 can be isolated from the reaction of boron nitride with iodine monofluoride at −30°C by sublimation at low temperature. Its low‐temperature Raman spectrum is consistent with a C3v molecular symmetry. equation image

Enhanced performance of the iodine monofluoride (491 nm) laser

The impact of substituting HI for CF/sub 3/I as the iodine donor in the discharge-pumped iodine monofluoride (IF) laser at 491 nm has been investigated. More than an order of magnitude improvement in output pulse energy has been observed and is attributed to more efficient production of low-lying (v'<5) vibrational levels of the IF (D') ion pair state. Preliminary evidence indicates that vibrational excitation of HI (X/sup 1/ Sigma /sup +/) assists in the relaxation of the D' state population. The increased net small-signal gain of D' to A' (v'=0 to v/sup "/) transitions in HI-containing gas mixtures has the effect of intensifying the 491-nm (0.15) bandhead relative to the lower gain transitions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Generation of high-number densities of iodine monofluoride in a supersonic flow

Iodine monofluoride, a promising visible chemical laser candidate, has been chemically produced at number densities exceeding 1×1015 molecules/cm3 in a supersonic flow. Combustion of nitric oxide and molecular fluorine produced atomic fluorine at an efficiency of 20%–30%, independent of flow conditions. The subsequent transonic reaction of atomic fluorine with molecular iodine to produce a stable flow of IF(X1Σ+) was mixing limited and complete within 10 μs. The low-pressure (3 Torr), low-temperature (300 K) flow environment should be suitable for lasing.

ChemInform Abstract: The A3π(1) → X1σ(0+) Emission Spectrum of Iodine Monofluoride: Analyses of the Vibrational and Rotational Structure

Abstract Iodine monofluoride A 3 Π(1) → X 1 Σ(0 + ) emission has been observed in the reaction of I 2 with F 2 at temperatures ranging from 300 to 800 K. Two previously unreported v ′ progressions are identified, and vibrational molecular constants are reported for the IF 3 Π(1) state using bandheads in progressions based on 0 ≤ v ′ ≤ 15 and 0 ≤ v ″ ≤ 5. The rotational structure has also been recorded and analyzed for nine vibrational bands. The triplet P -, Q -, and R -branch features are resolved for the first time which unambiguously confirms the Ω = 1 assignment of the emitting electronic state. Rotational molecular constants have been determined, and RKR potential energy functions are used to calculate Franck-Condon factors for the IF( A → X ) system.

The A3Π(1) → X1Σ(0+) emission spectrum of iodine monofluoride: Analyses of the vibrational and rotational structure

Iodine monofluoride A3Π(1) → X1Σ(0+) emission has been observed in the reaction of I2 with F2 at temperatures ranging from 300 to 800 K. Two previously unreported v′ progressions are identified, and vibrational molecular constants are reported for the IF3Π(1) state using bandheads in progressions based on 0 ≤ v′ ≤ 15 and 0 ≤ v″ ≤ 5. The rotational structure has also been recorded and analyzed for nine vibrational bands. The triplet P-, Q-, and R-branch features are resolved for the first time which unambiguously confirms the Ω = 1 assignment of the emitting electronic state. Rotational molecular constants have been determined, and RKR potential energy functions are used to calculate Franck-Condon factors for the IF(A → X) system.

State to state rotational transfer in collisions between IF molecules and helium atoms

We report measurements of the rate for transfer of population between rotational levels of the B state of iodine monofluoride in collisions with helium atoms. The measured rates are much larger than those observed for transfer of population between vibrational levels, indicating that the rotational population distribution in the collisionally pumped IF laser should be rapidly thermalized. The rates show a dependence on the quantum number of the initial level, in contrast to the results of theoretical calculations.