Simple Iodine Research Articles

Cascade [3 + 2] Annulation of 1,3-Dicarbonyl Compounds and Ethyl Secondary Amines for Pyrrole Synthesis via Poly C(sp3)-H Bond Functionalization.

The synthesis of polyfunctionalized pyrroles via the cascade reactions of 1,3-dicarbonyl compounds and two molecules of ethyl secondary amines has been realized via simple iodine catalysis in the presence of Dess-Martin periodinane (DMP). The formation of the target pyrrole products involves the formation of one new C-C and two new C-N bonds via the major functionalization of six C(sp3)-H bonds, presenting a highly novel and efficient synthetic protocol toward pyrrole scaffolds.

Evidence for Trans-Oligoene Chain Formation in Graphene Induced by Iodine.

Functionalization of pristine graphene by hydrogen and fluorine is well studied, resulting in graphane and fluorographene structures. In contrast, functionalization of pristine graphene with iodine has not been reported. Here, the functionalization of graphene with iodine using photochemical activation is presented, which is thermally reversible at 400°C. Additional dispersive dominant Raman modes that are probed by resonance Raman spectroscopy are observed. Additionally, iodinated graphene is probed by Kelvin probe force microscopy and by transport measurements showing p-doping surpassing non-covalent iodine doping by charge transfer-complex formation. The emergent Raman modes combined with strong p-doping indicate that iodine functionalization is distinct from simple iodine doping. A reaction mechanism based on these findings is proposed, identifying the large size of iodine atoms as the probable cause governing regiochemically controlled addition due to steric hinderance of reactive sites. The modification of the electronic structure is explained by the confinement of 1D trans-oligoene chains between sp3-defects. These results demonstrate the uniqueness of iodine reactivity toward graphene and the modification of the electronic structure of iodinated graphene, highlighting its dependence on the spatial arrangement of substituents.

A simple iodine-DMSO-promoted multicomponent reaction for the synthesis of 2,4-disubstituted dihydrotriazole-3-ones.

A series of 2,4-disubstituted 1,2,4-triazole-3-ones 4 were prepared via an iodine-DMSO-promoted three-component reaction of formaldehyde, amines and hydrazines in moderate yields.

Application of the new ICRP iodine biokinetic model for internal dosimetry in case of thyroid blocking

Administration of stable iodine has been considered a best measure to protect the thyroid from internal irradiation by radioiodine intake, and its efficacy on thyroid protection has been quantitatively evaluated in several simulation studies on the basis of simple iodine biokinetic models (i.e., three-compartment model). However, the new iodine biokinetic model adopted by the International Commission on Radiological Protection interprets and expresses the thyroid blocking phenomenon differently. Therefore, in this study, the new model was analyzed in terms of thyroid blocking and implemented to reassess the protective effects and to produce dosimetric data. The biokinetic model calculation was performed using computation modules developed by authors, and the results were compared with those of experimental data and prior simulation studies. The new model predicted protective effects that were generally consistent with those of experimental data, except for those in the range of stable iodine administration −72 h before radioiodine exposure. Additionally, the dosimetric data calculated in this study demonstrates a critical limitation of the three-compartment model in predicting bioassay functions, and indicated that dose assessment 1 d after exposure would result in a similar dose estimate irrespective of the administration time of stable iodine.

Iodine-steam functionalized reduced graphene oxide/oxidized carbon yarn electrodes for knittable fibriform supercapacitor

Fibriform supercapacitor (FSC) is considered as a promising energy storage component for future wearable electronics. The modification and fabrication of reduced graphene oxide (rGO) based FSC are recent research focus. Enhancing electrical conductivity of rGO is an important factor to improve the electrochemical performance of FSC. Hence, we fabricated iodine-functionalized reduced graphene oxide (I-rGO) on oxidized carbon yarn (OCY) by a simple iodine steam functionalization method. The I-rGO displays enhanced electrical conductivity which facilitates the ion and electron transport and increases the utilization of rGO. The I-rGO combined with the OCY which processes good hydrophilicity and high electrochemical activity very well, endowing the FSCs with high performance. The all-solid state FSC, assembled by using two intertwined I-rGO/OCY electrodes and KOH-polyvinyl alcohol gel electrolyte, shows high specific capacitance of 1.7 mF cm−1 at scan rate of 5 mV s−1 and the capacitance almost increases linearly with device length increasing. Meanwhile, the FSC exhibits well cycling performance of 88% capacitance retention after 5000 cycles, considerable mechanical flexibility and stability of 94% capacitance retention after 1000 continuous bending cycles, fascinating series-parallel performance and knittability. Therefore, the FSC based on I-rGO/OCY has great potential to be applied to wearable electronics in the future.

Radical Cation Initiated Surface Polymerization on Photothermal Rubber for Smart Antifouling Coatings.

Biofouling on surfaces of various materials has attracted considerable attention in biomedical and marine industries. Surface grafting based on covalent surface-initiated polymerization offers a popular route to address this problem by providing diverse robust polymer coatings capable of preventing the biofouling in complex environments. However, the existing methods for synthesizing polymer coatings are complicated and rigorous, or require special catalysts, greatly limiting their practical applications. In this work, a radical-cation-based surface-initiated polymerization protocol to graft the surface of darkened trans-polyisoprene (TPI) rubber with a thermo-responsive smart polymer, poly(N-isopropylacrylamide) (PNIPAM), through a simple iodine doping process is reported. A series of characterizations were performed to provide adequate evidence to confirm the successful grafting. Combining the thermal sensitivity of PNIPAM with the photothermal conversion ability of the darkened rubber, efficient bacteria-killing and antifouling capabilities were successfully achieved as a result of temperature-controlled iodine release and switchable amphiphilicity of PNIPAM.

CW molecular iodine laser pumped with a low power DPSSL

Cw oscillation of molecular iodine on many lines in the range of 557–802 nm pumped with a low power common diode pumped and frequency doubled solid state laser DPSSL is reported. The DPSSL is temperature stabilized, operates in single frequency and can be tuned by about 2 nm at 532 nm. Operation conditions of this simple and low cost iodine ring laser will be described and possible applications will be discussed.

Structural Stabilization of Tissue for Embryo Phenotyping Using Micro-CT with Iodine Staining

The International Mouse Phenotyping Consortium has been established to conduct large-scale phenotyping of the approximately 23,000 single-gene knockout mice generated by the International Knockout Mouse Consortium to investigate the role of each gene in the mouse genome. Of the generated mouse lines, 30% are predicted to be embryonic lethal, requiring the implementation of imaging techniques and analysis tools specific to late gestation mouse embryo phenotyping. A well-adopted technique combines the use of iodinated contrast solutions and micro-computed tomography imaging. This simple iodine immersion technique provides superior soft-tissue contrast enhancement, however, the hypertonic nature of iodine promotes dehydration causing moderate to severe tissue deformation. Here, we combine the stabilizing properties of a hydrogel mesh with the enhanced contrast properties of iodine. The protocol promotes cross linking of tissue through formaldehyde fixation and the linking of hydrogel monomers to biomolecules. As a result, the hydrogel supports tissue structure and preserves its conformation taking advantage of iodine-enhanced soft tissue contrast to produce high quality mouse embryo images with minimal tissue distortion. Hydrogel stabilization substantially reduces intersample anatomical variation of mature mouse embryos subjected to iodine preparation protocols. A 20% and 50% reduction in intersample variation of normalized brain and lung volume is achieved through hydrogel stabilization, as well as a 20% reduction in variation in overall embryo anatomy as measured through image registration methods. This increases the sensitivity of computer automated analysis to reveal significant anatomical differences between mutant and wild-type mice.

Daily urine iodine excretion while consuming a low-iodine diet in preparation for radioactive iodine therapy in a high iodine intake area

Recommended durations of low-iodine diet (LID) in preparation for radioactive iodine therapy (RAIT) vary among major guidelines and are important for patients in areas where iodine intake is high. The aim of this study was to investigate daily changes in urine iodine excretion after starting a LID. The daily iodine/creatinine (I/Cr) ratios and simple iodine concentration (simple I) of morning spot urine from 19 patients with differentiated thyroid carcinoma were measured for 2 weeks from the start of LID for RAIT preparation. We set the cut-off of I/Cr and simple I for poor LID preparation at >66·2 μg/gCr and >150 μg/l, respectively. The day when daily I/Cr or simple I became equal to or below the cut-off both by 95% CI and 90th percentile was defined as the end-point for the appropriate duration of LID for RAIT. On day 6 of LID, the I/Cr ratio decreased below the cut-off (≤66·2 μg/gCr) both by 95% CI (0-60·8) and by 90th percentile (51·9). Simple I reached the cut-off (≤150 μg/l) on day 3 by both parameters (95%CI: 2·3-90·5; 90th percentile: 126·5). The morning spot-urine I/Cr and simple I on day 7 and day 14 were significantly lower than on day 0 (P < 0·05). One week of a strict LID is enough to decrease the level of urine iodine excretion in preparation for RAIT even in high iodine intake areas. These results provide essential data for future outcome studies regarding LID preparation for RAIT.

The recovery of latent text from thermal paper using a simple iodine treatment procedure

Faded, or actively removed text on thermally printed paper samples may be enhanced and retrieved through the use of a simple iodine fuming procedure. The recovery of printed documentation evidence in this fashion is neither affected by prior fingerprint enhancement techniques (such as ninhydrin or DFO), nor by sample age. This method allows, for the first time, evidence to be obtained from completely faded thermal paper samples (receipts, for example) as well as allowing deliberately removed printed text (a consequence of solvent washing pre-treatment in latent fingerprint enhancement procedures) to be recovered.

An Efficient Iodine-Catalysed Knoevenagel Condensation Reaction in the Presence of Acetic Anhydride

A mild, simple and efficient iodine catalysed system has been developed for the Knoevenagel condensation of 1,3-dicarbonyl compounds with various aromatic aldehydes in the presence of acetic anhydride. The reaction gave good to excellent yields for a broad range of substrates.

Simple iodine reference at 1064 nm for absolute laser frequency determination in space applications

Using an iodine cell with fixed gas pressure, we built a simple frequency reference at 1064 nm with 10 MHz absolute accuracy and used it to demonstrate deterministic phase locking between two single-frequency lasers. The reference was designed to be as simple as possible, and it does not use a cooler or frequency modulator. This system should be useful, especially for space interferometric missions such as the Laser Interferometer Space Antenna.

Silver Surface Iodination for Enhancing the Conductivity of Conductive Composites

AbstractThe electrical conductivity of a silver microflake‐filled conductive composites is dramatically improved after a filler surface treatment. By a simple iodine solution treatment, nonstoichiometric silver/silver iodide nanoislands form on the silver filler surface. Evidence of the decrease of surface silver oxide species is provided by TOF‐SIMS and the redox property of the nanoclusters is studied using cyclic voltammetry and TOF‐SIMS depth profile analyses. The redox property of the nanoclusters on silver flakes helps enhance the electrical conductivity of the conductive composites. The electrical resistivity of the improved conductive composites is measured by four‐point probe method; the reliability of the printed thin film resistors is evaluated by both the 85 °C/85% relative humidity moisture exposure and the −40 ∼ 125 °C thermal cycling exposure. The conductive composite printed radio frequency identification (RFID) antennas with 27.5 wt% of the modified silver flake content show comparable performance in the RFID tag read range versus copper foil antennas, and better than those commercial conductive adhesives that require much higher silver content (i.e., 80 wt%). This work suggests that a surface chemistry method can significantly reduce the percolation threshold of the loading level of the silver flakes and improve the electrical conductivity of an important printed electronic passive component.

Silver Surface Iodination for Enhancing the Conductivity of Conductive Composites

AbstractThe electrical conductivity of a silver microflake‐filled conductive composites is dramatically improved after a filler surface treatment. By a simple iodine solution treatment, nonstoichiometric silver/silver iodide nanoislands form on the silver filler surface. Evidence of the decrease of surface silver oxide species is provided by TOF‐SIMS and the redox property of the nanoclusters is studied using cyclic voltammetry and TOF‐SIMS depth profile analyses. The redox property of the nanoclusters on silver flakes helps enhance the electrical conductivity of the conductive composites. The electrical resistivity of the improved conductive composites is measured by four‐point probe method; the reliability of the printed thin film resistors is evaluated by both the 85 °C/85% relative humidity moisture exposure and the −40 ∼ 125 °C thermal cycling exposure. The conductive composite printed radio frequency identification (RFID) antennas with 27.5 wt% of the modified silver flake content show comparable performance in the RFID tag read range versus copper foil antennas, and better than those commercial conductive adhesives that require much higher silver content (i.e., 80 wt%). This work suggests that a surface chemistry method can significantly reduce the percolation threshold of the loading level of the silver flakes and improve the electrical conductivity of an important printed electronic passive component.

Usefulness of iodine/creatinine ratio from spot‐urine samples to evaluate the effectiveness of low‐iodine diet preparation for radioiodine therapy

The success of a low-iodine diet (LID) is best determined by measurement of 24-h urine iodine (U-I) excretion. The aim of this study was to determine reliable estimates for 24-h U-I based on spot-urine samples and to provide cut-offs to determine the effectiveness of LID preparation. We prospectively measured iodine levels in 193 patients based on 24-h- and spot-urine samples before radioactive iodine therapy. The iodine was expressed as the 24-h U-I excretion (microg/day) and as two different indices from spot urine, simple iodine concentration (simple I) and the iodine/creatinine (I/Cr) ratio. Poor LID preparation was defined as I excretion of >150 microg/day according to the 24-h U-I measurement. The measured 24-h U-I was significantly higher than the two indices from spot urine (P < 0.001). However, there were statistically significant correlations between the 24-h U-I values and the two spot-urine-based indices; the correlation coefficient was 0.539 for simple I and 0.773 for I/Cr ratio (P < 0.001). The cut-off of I/Cr ratio for poor LID preparation was >66.2 microg/g Cr (sensitivity 96.4%, specificity 83.6%, positive predictive value 50.0% and negative predictive value 99.3%). We demonstrated that the I/Cr ratio from spot urine could serve as a useful and reliable alternative to 24-h urine collection as it has acceptable diagnostic values for detecting poor LID preparation.

Improved Synthetic Route to n-B18H22

Simple iodine oxidation of the B(9)H(12)(-) anion in toluene at room temperature reliably gives excellent yields ( approximately 80%) of n-B(18)H(22) (anti-B(18)H(22)) and thus provides a convenient, large-scale, safe route to this important polyborane cluster.

Brewing Science in the Chemistry Laboratory: A "Mashing" Investigation of Starch and Carbohydrates

In brewing science, mashing involves steeping malted barley in hot water. This activates the enzymes to breakdown the starch into simple sugars. The spent grains are then separated from the sweet wort. This experiment is an investigation of the chemistry and processes involved in mashing. Crushed malted barley is mixed with hot water and the progress of the reaction is monitored by using a simple iodine test for starch. This offers a very interesting way to study the enzymatic hydrolysis of starch.

Effect of iodide concentration upon the kinetics of disproportionation of hypoiodous acid in borate buffer

The disproportionation of hypoiodous acid into iodide and iodate has been studied over the pH range 8–13 and in the presence of between 0.004 and 0.1 mol I–1 of iodide. The recent model incorporating pre-equilibria between I2 and HOI, I2 and I2OH–, and HOI and IO– and rate-determining steps involving these simple iodine species has been found to account for the observed variation. At low pH the predominant reaction is between I2OH– and HOI molecules, not between two HOI molecules as has been commonly thought. Values of the relevant rate constants that take account of iodide variation are supplied.

Ligand-field splittings and core-level linewidths in I 4d photoelectron spectra of iodine molecules

High-resolution I 4d photoelectron spectra (total instrumental resolution ∼0.06 eV) of seven simple iodine molecules, ICl, IBr, I2, HI, CH3I, CH2I2, and CF3I, have been recorded. Ligand-field splitting (as measured by the asymmetric C20 crystal-field term) splits the 4d3/2 and 4d5/2 lines into a doublet and triplet, respectively. In contrast to Si 2p spectra, the I 4d spectra generally show little evidence for vibrational splitting or broadening. The C20 values, like the binding energies E4d, generally increase as the ligand electronegativity increases. C20 also correlates well with the nuclear field gradient, eqn, as measured by Mössbauer spectroscopy or nuclear quadrupole resonance. For the first time we have been able to study the chemical dependence of the inherent lifetime width of a core hole. We show that the I 4d linewidths generally decrease as the electronegativity of the ligand increases, and as the valence I 5p electron density decreases. We also show that there are large relaxation effects on E4d, C20 and especially the linewidth.

Iodine clock reaction mechanisms

Outlines the mechanism for the simple iodine clock reaction and the Old Nassau modification.