Metal Iodine Research Articles

Design, Synthesis and X‐ray Crystal Structure of Iodinated Benzoboroxole Derivatives by Consecutive Metal–Iodine Exchange of 3,4,5‐Triiodoanisole

A series of iodinated benzoboroxoles was designed and synthesized by using a successive metal–iodine exchange reaction of 3,4,5‐triiodoanisole. The reactivity and regioselectivity of the metal‐iodine exchange are remarkably controlled and provide the iodinated products in good yields. The synthesized iodobenzoboroxoles were screened for in vitro antimicrobial activity against two Gram‐positive strains of bacteria, Micrococcus luteus (ATCC 9341) and Bacillus cereus (ATCC 11778), and two Gram‐negative strains, Escherichia coli (ATCC 25922) and Serratia marcescens (ATCC 27117), by using a well‐diffusion assay and dilution methods. The in vitro antimicrobial evaluation indicated that 4‐iodo‐6‐methoxybenzo[c][1,2]oxaborol‐1(3H)‐ol (compound 24) possesses the most‐potent antibacterial activity against Gram‐positive strains with a minimum inhibitory concentration (MIC) of 0.016 and 0.013 mg/mL for Micrococcus luteus and Bacillus cereus, respectively. This report discloses a two‐step protocol for the synthesis of hitherto unknown 4‐iodobenzoboroxole and 7‐iodobenzoboroxole derivatives that is efficient, general in scope and scalable.

Mild, Efficient, and Regioselective Synthesis of Diiodophenyl­boronic Acid Derivatives via Metal–Iodine Exchange of 5-Substituted 1,2,3-Triiodoarenes

Unique 2,6-diiodophenylboronic acid and 2,3-diiodophenylboronic acid derivatives have been synthesized via regioselective metal–iodine exchange (MIE) of 5-substituted 1,2,3-triiodoarenes. The regio­selectivity of the reaction per se is remarkably controlled by the nature of the C5 substituent providing the desired diiodophenylboronic acids in moderate to good yields and with high site selectivity. The diiodophenylboronic acids were then examined for in vitro antimicrobial activity against four strains of bacteria Micrococcus luteus (ATCC 9341), Bacillus cereus (ATCC 11778), Escherichia coli (ATCC 25922), and Serratia marcescens (ATCC 27117) and one fungal strain Candida albicans using well diffusion assay and dilution method. It indicated that 5-fluoro-2,3-diiodophenylboronic acid possesses the most potent antibacterial and antifungal activity with MIC of 2.6 mg/mL for M. luteus and C. albicans. This report discloses a one-step protocol to access hitherto unknowns 2,6-diiodophenylboronic acid and 2,3-diiodophenylboronic acid derivatives that is scalable, good in scope, no chromatography is needed, and these compounds are difficult to prepare by other means.

Compositional dependence of the optical properties of novel Ga–Sb–S–XI (XI = PbI2, CsI, AgI) infrared chalcogenide glasses

AbstractA novel family of Ga2S3–Sb2S3–XI (XI = PbI2, CsI, AgI) was investigated to understand the role of metal halides and exploit new chalco‐halide glasses for infrared optics. The dependence of the thermal properties, infrared optical properties, and structural information of the novel family on different metal–iodines was investigated. Results showed that metal halides increase the glass stability but decrease the glass network connectivity. The compositional dependence of the short‐wave cut‐off edge is associated with the electronegativity difference between the cations and anions of the metal halides. Raman study showed that the metal–iodine modified the glass structure mainly through the iodide content, and the cations dissolved in the glass network mostly as charge compensators for the aperiodic network. For the glasses in the series Ga2S3–Sb2S3–XI–Dy3+, Dy3+ emission increased in the PbI2‐ and CsI‐doped glasses but decreased in the AgI‐doped glass due to the combined effect of dysprosium and oxygen. For all that, these novel glasses are highly promised for use in infrared optics.

Dual energy CT angiography: pros and cons of dual-energy metal artifact reduction algorithm in patients after endovascular aortic repair.

To evaluate the value of metal artifact reduction (MAR) post-processing and iodine MD images in fast kV-switching dual-energy computed tomography (DECT) in patients after endovascular aortic repair (EVAR). Twenty-four consecutive EVAR patients (age 76±9years, 7/24 (29%) with coils, 9/24 (37.5%) with 10 endoleaks) who underwent DECT angiography were included in this HIPAA-compliant, IRB-approved retrospective study. Monochromatic reconstructions included 55, 60, 65, 70, and 75keV with and without MAR and iodine MD images. Near field, far field, and vessel artifacts were assessed subjectively (1=none; 5=severe) and objectively by measuring noise and contrast-to-noise ratio. Visibility of endoleak was evaluated (1=optimal; 5=not visible). MAR objectively decreased artifacts from EVAR stents in the near field (60.7±25.4HU vs. 70.1±34.2; p=.002) and subjectively increased near field (3.2±0.9 vs. 2.8±0.6; p<.001), far field (2.2±0.6 vs. 1.6±0.6; p<.001), and vessel (3.1±1.1 vs. 2.5±0.9; p<.001) artifacts. Near-field artifacts from coils were reduced by the MAR objectively (72.4±24.8 vs. 182.7±57.3HU; p<.001) and subjectively (4.5±0.5 vs. 4.9±0.4; p=.02). CNR of standard reconstructions was optimal at 60keV (38.3±16.8). Reconstructions without MAR and iodine MD images provided improved endoleak visualization in 6/10 (60%) of cases (median 1 for both) compared to MAR (median 3) (p<0.001). However, MAR improved visualization in 1/10 (10%) cases due to endoleak location adjacent to a coil. DECT with MAR reduced artifacts from coils and improved endoleak visualization in 1/10 (10%) cases due to location adjacent to a coil. However, MAR impaired endoleak visualization in 6/10 (60%) cases and should be reviewed combined with 60keV standard reconstructions and iodine MD images.

ChemInform Abstract: π‐Conjugated Carbocycles and Heterocycles via Annulation Through C—H and X—Y Activation Across CC Triple Bonds

AbstractReview: 120 refs.

Poly(vinyl alcohol) Based Polymer Gel Electrolytes: Investigation on Their Conductivity and Characterization

Polymer gel electrolytes were prepared using poly(vinyl alcohol) (PVA) as polymer matrix. 1-methyl-2pyrrolidone (NMP) and γ-butyrolactone (GBL) were preferred as the organic solvents. The alkali metal iodide salt (KI) and iodine (I2) were used as the redox couple. Liquid electrolytes with different concentrations of KI were prepared by dissolving iodide salt/iodine in the binary NMP:GBL (volume ratio 7:3) solvent mixture. PVA was added into the liquid electrolytes and then the resulting mixture was stirred at 110 ◦C for 1 h. Gel form was obtained at room temperature. The highest ionic conductivity at room temperature is 8.41 mS/cm. The temperature dependence of ionic conductivity with respect to the all concentration of KI shows the Arrhenius behaviour. Characterizations of polymer gel electrolytes were performed using the Fourier transform infrared, thermal gravimetric analysis, and differential scanning calorimetry techniques.

π-Conjugated carbocycles and heterocycles via annulation through C-H and X-Y activation across CC triple bonds

 In this account our own research results on the methods of annulation and hetero-annulation across alkynes are summarized, especially emphasizing the annulation and hetero-annulation through C-H and X-Y activation. A wide range of quinolines, isoquinolines, indoles, benzofurans, indenes, and benzothiophenes can be synthesized via mono-annulation of ortho-alkynylaryl derivatives using transition metal catalysts and/or iodine reagents. Benzocarbazoles, benzonaphthothiophenes, and indenochromenes can be synthesized via cascade annulation of 1,2-dialkynyl substituted benzene derivatives. Palladium-catalyzed crossover annulation of compounds bearing two vicinal CC triple bonds attached to an unsaturated ring gives dibenzopentalenes through C-H activation, and intramolecular cross annulation of bisbiarylalkynes affords 9,9-bifluorenylidenes via dual C-H activation.

Facile, One‐Pot, and Gram‐Scale Synthesis of 3,4,5‐Triiodoanisole through a C–H Iodination/ipso‐Iododecarboxylation Strategy: Potential Application towards 3,4,5‐Trisubstituted Anisoles

AbstractA facile, efficient, and gram‐scale method for the conversion of para‐anisic acid into 3,4,5‐triiodoanisole through a one‐pot C–H iodination/ipso‐iododecarboxylation reaction was investigated. Commercially available benzoic acid was used, which allowed the reaction to be performed on a multigram scale in good yield. This report discloses a practical method for the one‐pot synthesis of hitherto unknown 3,4,5‐triiodoanisole that is catalytic, scalable, efficient, and easy to work up and purify. Potential application of the target compound as a precursor for novel site‐selective metal–iodine exchange and Suzuki–Miyaura cross‐coupling reactions were also explored. 3,4,5‐Trisubstituted anisole derivatives were provided in a highly regioselective fashion; these compounds are useful building blocks in synthesis and indeed are hard to prepare by any other means.

Monoenergetic extrapolation of cardiac dual energy CT for artifact reduction

Monoenergetic extrapolation of cardiac dual-energy computed tomography (DECT) could be useful in artifact reduction in clinical practice. To evaluate the potential of monoenergetic extrapolation of cardiac DECT data for reducing artifacts from metal and high iodine contrast concentration. With IRB approval and in HIPAA compliance, 35 patients (22 men, 61 ± 12 years) underwent cardiac DECT with dual-source CT (100 kVp and 140 kVp). Contrast material injection protocols were adapted to the patient's weight using non-ionic low-osmolar 370 mgI/mL iopromide. Datasets were transferred to a stand-alone workstation and dedicated monoenergetic analysis software was used for postprocessing. Reconstructions with the following five photon energies were generated: 40 keV, 60 keV, 80 keV, 100 keV, and 120 keV. Artifact severity was graded on a 5-point Likert scale (0, massive artifact; 5, absence of artifact). The size of artifact and image noise (expressed as HU) in anatomic structures adjacent to the artifact were measured. Quantitative and subjective image quality was compared using Friedman and Wilcoxon tests. We observed artifacts arising from densely concentrated contrast material in the superior vena cava (SVC) in 18 patients, from sternal wires in 14, from bypass clips in eight, and from coronary artery stents in seven. Artifact size in monoenergetic reconstructions from 40 to 120 keV decreased from 21.3 to 19 mm for the SVC (P < 0.001), from 8.4 to 2.6 mm for sternal wires (P < 0.001), from 6.4 to 2.2 mm for bypass clips (P < 0.001), and from 5.9 to 2.7 mm for stents (P < 0.001), respectively. The quality score changed from 0.2 to 3.8 for the SVC (P < 0.001), from 0.1 to 4 for sternal wires (P < 0.001), from 0 to 3.9 for bypass clips (P < 0.001), and from 0 to 3.9 for stents (P < 0.001). Lowest noise in adjacent structures was found at 80 keV for the SVC (39.1 HU), for sternal wires (33.3), for bypass clips (26.9), and for stents (33.9). A significant reduction of high-attenuation artifacts can be achieved by use of higher monoenergetic energy levels with cardiac DECT. However, image noise in anatomic structures affected by artifacts is lowest at 80 keV, which suggests an evaluation approach that makes use of multiple energy levels for a complete diagnosis.

A Simple and Efficient Two-Step Synthesis of 1,2,3-Triiodoarenes via Consecutive C–H Iodination/ipso-Iododecarboxylation Strategy: A Potential Application towards ortho-Diiodoarenes by Regioselective Metal–Iodine Exchange Reaction

A general, robust, and efficient method for the conversion of benzoic acids to 1,2,3-triiodoarenes and 1,2,3-trihaloarenes via a two-step synthesis is reported. Commercially available benzoic acids were used that can allow the reactions to be performed on multi-gram scales with good-to-excellent yields. This report discloses a practical method for the synthesis of 1,2,3-triiodoarenes and 1,2,3-trihaloarenes that is general in scope, scalable, and easy to workup and purify. A potential application of the target compounds as precursors for novel regioselective metal–iodine exchange reaction of 1,2,3-triiodoarenes was also demonstrated. It provided ortho-diiodoaryl derivatives in a high regioselective fashion that are useful intermediates in synthesis and indeed are hard to synthesize by any other means.

Using Trace Metals, Peroxide, Acid and Iodine Values to Characterize Oils Bleached Using Clays from Central and Eastern Uganda

Bleaching of edible oils is known to alter the composition of oils as it removes impurities and certain food nutrients. The characteristics of bleached oil are strongly related to type bleaching medium, temperature at which bleaching is done and other factors. In this study, we compare peroxide, free fatty acid, acid and iodine values, copper and iron content of bleached and crude oils to establish the characteristics of edible oils bleached using smectite and kaolinite-rich clays. Oil industries spend large sums of money purchasing bleaching earths yet no country lacks natural clays which can be developed to bleach oils. In Uganda alone more than US$ 700,000 is spent every month yet many clay deposits are unexploited. In this study, we have documented trace metal composition, peroxide values, acid values, iodine values and free fatty acid content of bleached and unbleached cotton-seed and sunflower seed oils. The bleached oils were found to be fit for human use. Clays are either kaolinites or smectites, but the clays used to bleach edible oils are montmorillonites or bentonites. The decrease in content of iron in the bleached oils was highest for all oils bleached. The content of copper showed the smallest change. The content of copper in cotton oils decreased from 0.5 ppm to 0.15 ppm using Kajansi clay leached in 20% acid yet when Chelel clay leached under similar conditions was used decrease was from 0.5 to 0.1 ppm. The content of iron in sunflower oils bleached using Kajansi clay leached in 20% acid decreased from 1.6 to 0.2 ppm yet that bleached with Chelel clay under similar conditions decreased to 0.1 ppm. The acid values showed that the acidity in sunflower oils is largely due to oleic acid as the average value for acids is in the range close to oleic acid, cotton-seed oil corresponded to linoleic acid. The levels of free fatty acid were found to lie in range from 3.8 - 3.2 for all clays used showing no significant rise. The peroxide values of bleached oils lay between 1.2 and 0.8.

New compounds based on polyoxometalates and metal halide clusters

Seven new compounds based on polyoxometalates and metal halide clusters have been synthesized and characterized by IR, XPS, UV-vis, XRD, elemental analyses and single crystal X-ray diffraction analyses. Compounds 1, 2, 3 and 4 are hybrids based on polyoxometalates and ennea-nuclear metal halide clusters, which are isomorphous to the compounds we reported recently. Compounds 5–7 are new examples of hybrids based on polyoxometalates and metal halide clusters, of which compounds 5 and 6 are the first examples of hybrids based on polyoxometalates and a new kind of hepta-nuclear metal halide cluster and compound 7 is the first example of hybrid based on polyoxometalates and octakaideca-nuclear metal halide clusters. In addition, compounds 2, 3 and 4 are the first examples of hybrids based on polyoxometalates and metal bromide clusters, and compounds 5 and 6 are the second examples of hybrids based on polyoxometalates and metal iodine clusters. Furthermore, compound 7 is the first example of compounds based on POMs and metal halide extended structures.

ChemInform Abstract: Facile Preparation of α‐Glycosyl Iodides by in situ Generated Aluminum Iodide: Straightforward Synthesis of Thio‐, Seleno‐, and O‐Glycosides from Unprotected Reducing Sugars.

A facile and practical protocol was developed for the synthesis of glycosyl iodides using AlI3 generated in situ from cheap aluminum metal and molecular iodine. Furthermore, in combination with iodine-catalyzed per-O-acetylation, sequential synthesis of per-acetylated glycosyl iodides, per-acetylated thioglycosides, selenoglycoside, and O-glycosides from unprotected reducing sugars was also achieved with complete diastereocontrol in a one-pot version. Supplemental material is available for this article. Go to the publisher's online edition of Journal of Carbohydrate Chemistry to view the free supplemental file.

Catalytic hydroxylation of [Closo-B12H12]2−—adaptation of the Periana reaction to a polyhedral borane

Per-B-hydroxylation of a polyhedral borane anion has been demonstrated by the catalytic hydroxylation of icosahedral [closo-B(12)H(12)](2-) using soft electrophiles such as platinum group metal catalysts or iodine cation. A new route to [closo-B(12)(OH)(12)](2-) from [closo-B(12)H(12)](2-) without the use of H(2)O(2) oxidant provides an alternative hydroxylation process.

Facile Preparation of α-Glycosyl Iodides by In Situ Generated Aluminum Iodide: Straightforward Synthesis of Thio-, Seleno-, and O-glycosides from Unprotected Reducing Sugars

A facile and practical protocol was developed for the synthesis of glycosyl iodides using AlI3 generated in situ from cheap aluminum metal and molecular iodine. Furthermore, in combination with iodine-catalyzed per-O-acetylation, sequential synthesis of per-acetylated glycosyl iodides, per-acetylated thioglycosides, selenoglycoside, and O-glycosides from unprotected reducing sugars was also achieved with complete diastereocontrol in a one-pot version. Supplemental material is available for this article. Go to the publisher's online edition of Journal of Carbohydrate Chemistry to view the free supplemental file.

La2TeI2: A New Layered Telluride Iodide with Unusual Electrical Properties

A new layered metal-rich telluride halide, La2TeI2, has been synthesized by heating stoichiometric mixtures of LaI3, La, and Te under argon at 900 degrees C, and its structure has been refined from X-ray powder diffraction data. The compound crystallizes in the 3R-Lu2CCl2 structure type (rhombohedral space group R(-)3m with a = 4.5074(4) A, c = 32.528(2) A, and Z = 3). The crystal structure is composed of infinite layers of edge-sharing, Te-centered metal atom octahedra and iodine atoms separating these layers to form three close-packed I-Ln-Te-Ln-I slabs within the unit cell. The title compound is metallic at room temperature and exhibits an anomaly in the resistivity around 140 K which is closely related to changes in the a lattice parameter with temperature. The chemical bonding and metallic properties of La2TeI2 can be plausibly understood in terms of an ionic description (Ln3+)2Te2-(I-)2(e)2 where two electrons are delocalized in the La 5d conduction band.

Reactivity of Polyiodides Towards 1,3‐Bis(4‐pyridyl)propane (bpp): A New CuI Cluster Polycatenane Framework and a Novel 2D AgI Cluster Motif

AbstractThe solution‐phase reactions of metal iodides or iodine with 1,3‐bis(4‐pyridyl)propane (bpp) yields four new organic–inorganic hybrid frameworks, namely [(CuI)4(bpp)4]n(1), [(AgI)6(bpp)]n (2), [PbI2(bpp)]n (3), and [I3(bppH)] (4), each of which adopts a different structural motif. For example, complex 1 is a 2D “open” coordination polymeric cluster consisting of a CuI2Cu rhomboid cluster core coordinated by anti‐anti and anti‐gauche bpp interactions to produce an interpenetrating 2D (4,4) polycatenane net; 2 is a novel bpp inclusion compound with a unique 2D polymeric hexagonal prism‐shaped [Ag6I6]n cluster motif; compound 3 is also a 2D “open” supramolecular cluster made from [PbI2]n “ribbons” and bpp bridges; compound 4 is a triiodide made up of organic [bppH]+ cations and a I3– anion chain. The clusters 1–3 obtained from the reaction between polyiodide complexes and an organic ligand suggest that this simple synthetic approach is likely to be applicable to the construction of polymeric clusters. The third‐order NLO effects of 1 were studied by Z‐scan techniques. The polymeric cluster exhibits good nonlinearities and the effective third‐order NLO refractive index (n2) value is 2.56 × 10–12 esu which is comparable to those of most cluster monomers and polymers. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2006)

Synthesis and characterization of N‐vinyl pyrrolidone and cellulosics based functional graft copolymers for use as metal ions and iodine sorbents

AbstractTo develop cost effective and eco friendly polymeric materials for enrichment and separation technologies, 1‐vinyl‐2‐pyrrolidone (N‐VP) was graft copolymerized onto cellulose, extracted from pine needles. Optimum conditions have been evaluated for the grafting of N‐VP onto cellulose and at these conditions it was also grafted onto cellulose phosphate, hydroxypropyl cellulose, cyanoethyl cellulose, and deoxyhydrazino cellulose. At the optimum grafting conditions for N‐VP, it was also cografted with maleic anhydride. Kinetics of radiochemical graft copolymerization has been studied and evaluation of the polymerization and grafting parameters as percent grafting, percent grafting efficiency, rate of polymerization, homopolymerization, and graft copolymerization have been evaluated. Graft copolymers have been characterized by elemental analysis, FTIR, and swelling studies. An attempt has been made to study sorption of some metal ions such as Fe2+ and Cu2+ and iodine on select graft copolymers to investigate selectivity in metal ion sorption and iodine sorption as a function of structural aspects of the functionalized graft copolymers to find their end uses in separation and enrichment technologies. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 373–382, 2005

Numerical simulation of metal-halide lamp using a time-dependent two-dimensional model

Numerical simulation of a vertically held metal-halide lamp (Hg/Na/Sc system) is presented. The lamp was driven by an ac current of 60 Hz. The model took convection and diffusion of various species into account. A method for rapid calculation of optically thick radiation power was developed. Density of scandium ions and sodium ions has a minimum on the central axis due to radial ambipolar diffusion. Density of metallic atoms and ions and metal iodine molecules decreases with increasing axial distance from the bottom of the tube. This tendency was explained by convection and diffusion. The density of scandium ions depends on the direction of the current; the density was greater at upward current than at downward current.

ChemInform Abstract: A New Sandmeyer Iodination of 2‐Aminopurines in Non‐Aqueous Conditions: Combination of Alkali Metal Iodide and Iodine as Iodine Sources.

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