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Examines the spectroscopic detection and characterization of iodogermylene. Use of pulsed discharge and laser-induced fluorescence techniques; Analysis of the partially resolved rotational structure of the energy bands; Account on the fluorescence lifetime of the monoiodogermylene.

The uptake process and physiological reaction of plants to aromatic iodine compounds have not yet been documented. The aim of this research was to compare uptake by tomato plants of KI and KIO 3 , as well as of organic iodine compounds – 5-ISA (5-iodosalicylic acid), 3,5-diISA (3,5-diiodosalicylic acid), 2-IBeA (2-iodobenzoic acid), 4-IBeA (4-iodobenzoic acid) and 2,3,5-triIBeA (2,3,5-triiodobenzoic acid). Only 2,3,5-triIBeA had a negative influence on plant development. All organic iodine compounds were taken up by roots and transported to leaves and fruits. Among all the compounds applied, the most efficiently transferred iodine was 2-IBeA – to fruits, and 4-IBeA – to leaves. The order of iodine accumulation in fruit cell compartments was as follows: organelles > cell walls > soluble portions of cells; for leaf and root cells, it was: organelles > cell walls or soluble portions, depending on the compound applied. The compounds studied influence iodine metabolism through expression of the HMT gene which encodes halide ion methyltransferase in leaves and roots. Also, their influence on modification of the activity of the SAMT and S3H genes that encode salicylic acid carboxyl methyltransferase and salicylic acid 3-hydroxylase was established. It was discovered that exogenously applied 5-ISA, 3,5-diISA, 2-IBeA and 4-IBeA are genuinely (endogenously) synthesised in tomato plants; to date, this has not been described for the tomato, nor for any other species of higher plant. • Iodosalicylates and iodobenzoates can be a good source of iodine for biofortification of tomato plants. [ABSTRACT FROM AUTHOR]

In contrast to aryliodine(III) compounds, which have matured into a particularly attractive class of oxidants in modern synthesis, the synthetic potential of related alkyliodine(III) derivatives has remained widely underestimated. This is surprising since several unique synthetic possibilities arise directly from the low stability of their central carbon–iodine bond. In this respect, these high‐oxidation‐state iodine compounds resemble environmentally benign variants of the prominent metal counterparts such as those derived from palladium, nickel and copper. This Concept article summarizes the general reactivity trends in alkyliodine(III) chemistry and discusses selected examples of their strategic use as highly reactive, transient species in organic synthesis and homogeneous catalysis. [ABSTRACT FROM AUTHOR]

Hypervalent iodine compounds are known for their extensive use as potential oxidants in organic synthesis. In spite of the similar reactivity with transition metals, hypervalent iodine reagents are more preferred because of their environmental sustainability. Among several types of hypervalent iodine reagents, trivalent organoiodine(III) reagents are highly popular due to their easy accessibility, stability and controlled oxidizing reactivity. Also, iodine(III) reagents are commercially available and inexpensive. Amines and amides react with iodine(III) oxidants in some specific way to provide a divalent electrophilic ionic species known as a nitrenium ion. Depending on the nature and stability of the nitrenium ion, numerous oxidative transformations to generate valuable functional molecules have been reported. This review encompasses discussions about hypervalent organo iodine(III)‐enabled organic transformations with the involvement of a nitrenium ion as an intermediate. [ABSTRACT FROM AUTHOR]

Background Population iodine deficiency is indicated by >3% of the population with newborn thyroid-stimulating hormone (TSH) concentration >5 mIU/L, median urinary iodine concentration (MUIC) <100 µg/L, or >5% prevalence of goiter in school-age children. However, the agreement between these population markers has not been systematically investigated. Objective To assess the agreement between TSH, MUIC, and goiter as markers of population iodine status. Methods We performed a systematic search for studies published on PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, and PsycINFO up to 29 October, 2018. Studies assessing iodine status in the population using the TSH marker and either MUIC or goiter prevalence in school-age children were included. The agreement between markers in classifying iodine status of the population was assessed. The sensitivity and specificity of the TSH marker was determined against MUIC and goiter prevalence as the reference markers. Results Of 17,435 records identified by the search strategy, 57 eligible studies were included in the review. The agreement between markers in classifying the iodine status of populations into the same category was 65% for TSH and MUIC, and 83% for TSH and goiter prevalence. The TSH marker had a sensitivity of 0.75 and specificity of 0.53 when compared with MUIC, and 0.86 and 0.50 when compared with goiter prevalence. Conclusions The TSH marker has a better agreement with goiter prevalence than MUIC when classifying the iodine status of populations. Re-evaluation of the current criteria for classifying the iodine status of populations using the TSH marker is warranted. This systematic review was registered at PROSPERO (http://www.crd.york.ac.uk/prospero/) as CRD42018091247. [ABSTRACT FROM AUTHOR]

A catalyst‐ and additive‐free simple and straightforward method for regioselective direct sp2 C–H acetoxylation reaction of aldehyde hydrazones has been achieved at ambient temperature employing PIDA as an acetoxy source. The scope of the reaction has been successfully verified with a wide range of biologically important aldehyde hydrazones with diverse functional group tolerance. The method is highly selective, mild and efficient, operationally simple, rapid and high‐yielding. [ABSTRACT FROM AUTHOR]

Hypervalent iodine compounds constitute a popular class of reagents in organic chemistry. Regardless of whether they are generated in situ from an iodoarene precursor with a terminal oxidant or used in stoichiometric amounts, the resulting separation and waste issues are major challenges en route to sustainable and scalable processes. The electrochemical generation of iodine(III) compounds represents an attractive alternative, since electric current is used as traceless oxidant and unstable or hazardous species are conveniently generated in situ. In this context, we have explored the possibility for the use of iodoarene sulfonates and iodobenzoates as ex‐cell mediators for electrosynthesis in 1,1,1,3,3,3‐hexafluoroisopropanol. While 2‐, 3‐ and 4‐iodobenzoate salts proved to be impractical for various reasons, 2‐ and 4‐iodobenzenesulfonates salts can be selectively oxidized to the iodine(III) species and used for synthetic applications. The ionic tag on the mediator allows for electrolysis without supporting electrolyte additives and enables a straightforward recovery from the product mixture. [ABSTRACT FROM AUTHOR]

Fission products recoiling from a 252Cf spontaneous fission source were stopped in various mixtures of inert gases containing CO and NO. For the elements of the transisition metal series Mo, Tc, Ru, and Rh previous observations of pure carbonyl complexes were reproduced. However, no formation of volatile mixed nitrosyl-carbonyl complexes or pure nitrosyl complexes for these elements have been observed. Instead, efficient production of volatile nitrosyl compounds for single iodine atoms, presumably nitrosyl iodide, NOI, was detected. This observation is of interest as potential transport path for iodine in nuclear accident scenarios and as a model for radiochemistry with the recently discovered heaviest halogen tennessine (Z=117). [ABSTRACT FROM AUTHOR]

The paper presents the results of investigation of phase transitions in the intercalation compounds based on fine crystalline anisotropic pyrolytic graphite with iodine chloride and bromine by X-ray diffraction method. As a source for intercalation, the fine crystalline pyrolytic anisotropic graphite with a distance between neighboring graphite layers of 0.340 nm and a crystallite size of 20 nm was used. The intercalation reaction was carried out by standard two-temperature gas-phase method. The stability of graphite intercalation compounds under normal conditions is investigated. It is found that the exposure of graphite intercalation compound with iodine chloride under normal conditions during 20 days has not led to significant changes in the structure of compound while such exposure for graphite intercalation compound with bromine causes some changes in the structure. In particular, transition from the second stage compound to the third stage compound is observed. The coefficient of linear thermal expansion for graphite intercalation compounds with iodine chloride in different temperature intervals is estimated. It is revealed that at a temperature of 260 K there is a significant reduction of the value of the coefficient of linear temperature expansion. It is shown that such a sharp change of the coefficient of linear temperature expansion is related to the phase transition in the intercalate layers from quasicrystalline” state to “quasiliquid” state. For the first time, by the X-ray diffraction method the phase transition of the “disorder – order” type in the intercalate layers is found for graphite intercalation compounds with iodine chloride. [ABSTRACT FROM AUTHOR]

An efficient protocol for C–H condensation of hypervalent iodine compounds toward arenes in fluoroalcohols has been applied to the recyclable preparation of mesityl iodonium(III) salts. The electrophilicities of [hydroxy(tosyloxy)iodo]mesitylene (MesI(OH)OTs) and iodomesitylene diacetate (MesI(OAc) 2) are suitably enhanced in 2,2,2-trifluoroethanol. A series of nucleophilic aromatic compounds react smoothly with MesI(OH)OTs and MesI(OAc) 2 or in situ hypervalent iodine(III) species, generated from iodomesitylene, to provide the target mesityl iodonium(III) salts in good yields at room temperature with broad functional group tolerance. This C–H condensation strategy merits high para -regioselectivities during the diaryliodonium(III) salt formation, but the major limitation in the case of low-reactive aromatic substrates is byproduct formation resulting from the self-condensation of the nucleophilic mesitylene ring in MesI(OH)OTs and MesI(OAc) 2. Image 1 [ABSTRACT FROM AUTHOR]

A facile method for the regioselective hydrodifluoromethylation of alkenes is reported using difluoroacetic acid and phenyliodine(III) diacetate in tetrahydrofuran under visible‐light activation. This metal‐free approach stands out as it uses inexpensive reagents, does not require a photocatalyst, and displays broad functional group tolerance. The procedure is also operationally simple and scalable, and provides access in one step to high‐value building blocks for application in medicinal chemistry. [ABSTRACT FROM AUTHOR]

We report herein the synthesis of highly substituted and stereochemically well‐defined vinylbenziodoxole (VBX) derivatives through hydrochlorination and iodochlorination of ethynylbenziodoxoles. The hydrochlorination is achieved using pyridine hydrochloride as an HCl source in an anti‐fashion under mild, open‐air conditions to afford a 2‐chlorinated VBX product, which serves as a useful building block for the stereoselective synthesis of trisubstituted alkenes. Meanwhile, iodochlorination with iodine monochloride proceeds in an unusual syn‐pathway, stereoselectively affording a tetrasubstituted VBX derivative. [ABSTRACT FROM AUTHOR]

Purpose: Oral administration of Iodine−131 (I−131) solutions causes high risk of contamination for patients and dispensers. The objective of the study was to adapt hard gelatin capsules (HGCs) for filling with radiopharmaceutical solutions without deformation. Methods: Polystyrene (PS) internally lining films with different thicknesses were used to protect HGCs. The insulated HGCs were evaluated for their physicochemical characteristics and rupturing time in different dissolution media. HGCs internally lined with PS were examined for withstand loading with different volumes and radioactivities of I−131 solutions. Radioactivity release was studied in deionized water and acidic media. Quality control of released I−131 was inspected for radiochemical purities. Results: There was a directly proportion between PS lining thickness and stability of HGCs after filling with 500 μl aqueous methylene blue solution. HGCs internally lined with PS 100 μm thickness withstand deformation for ˃ two months; however showed fast in-vitro rupturing time in different dissolution media. Internally lined HGCs loaded with different volumes and radioactivities of I−131 solutions resisted for one week without radioactive leakage. Yet, revealed complete release of I−131 after 20 min in dissolution media with great radiochemical purity. Conclusion: The study promises safely I−131 aqueous solution delivery via adapted HGCs. [ABSTRACT FROM AUTHOR]

The approaches to increasing the efficiency of lithium–oxygen battery (LOB), which are based on the use of PtCo/carbon nanotubes (CNT) catalyst and iodine-containing liquid-phase mediator, are compared. It is found that, when 1 M LiClO4/DMSO electrolyte is used, the 20PtCo/CNT catalyst provides an increase of the capacity of a Swagelok LOB model in the complete discharge to a voltage of 2 V as compared to the CNT-based LOB. During the cycling of LOB with each of the materials, the charging voltage increases to 4.5 V. This leads not only to an increase in the rate of electrochemical oxidation of lithium peroxide, but also to an acceleration of corrosion of the electrolyte and active material. In the presence of iodine compounds in the electrolyte, Li2O2 is oxidized by the chemical mechanism, which reduces the charging voltage. In the 0.05 M LiI + 1 M LiClO4/DMSO electrolyte, 85 successive cycles were obtained at a capacity of 500 mA h/gС in the LOB discharging stage and a final charging voltage of not more than 3.8 V. When scaling the LOB to the size of the positive electrode (5 × 5 cm2), the complete discharge capacity close to this characteristic of Swagelok model (as calculated for the geometric electrode surface area) was reached. An introduction of iodine-containing additive into the electrolyte enabled us to obtain up to 100 cycles at a capacity of 300 mA h/gC. The results of the work show that the use of iodine-based redox mediator is more effective from the viewpoint of stability of characteristics of LOB of this type as compared with the use of the platinum-containing catalyst. [ABSTRACT FROM AUTHOR]

• The CMPs possess high BET surface area, can both adsorb and fluorescent sense iodine. • The both CMPs show excellent efficient absorption performance for iodine vapor up to 4.15 and 3.65 g g−1. • TS-TAD and TS-TADP exhibits high sensitivity to I 2 , o-NP, and PA via fluorescence quenching. Two new spirobifluorene-based conjugated microporous polymers, TS-TAD and TS-TADP, were constructed via Friedel-Crafts coupling reactions. TS-TAD and TS-TADP possess high BET surface area of 828 and 783 m2 g−1, large pore volume of 1.51 and 0.54 cm3 g−1, good stability, and display excellent guest uptake of 4.15 and 3.65 g g−1 in iodine vapour as well as reversible adsorption of iodine in solution. The specific surface areas of CMPs were increased by the introduction of bispirofluorene rings compared with the corresponding parent polymers. TS-TAD has a similar structure to TS-TADP, but possesses larger specific surface area and pore values than TS-TADP, hence, TS-TAD has a higher adsorption capacity for iodine than TS-TADP. Moreover, the adsorption rate of TS-TAD is slower than that of TS-TADP in I 2 vapor, while it is faster than that of TS-TADP in cyclohexane solution. We also highlight that the both resulting CMPs exhibit outstanding performance for fluorescent sensing to iodine and nitroaromatic compounds, thus making the resulting CMPs ideal absorbent materials for reversible iodine capture, sensing iodine and nitroaromatic compounds to address environmental issues. [ABSTRACT FROM AUTHOR]

The specific emission rates of iodine isotopes into the atmosphere during normal operation of European and Russian NPPs with different types of reactor facilities were analyzed. The probability distributions for the specific parameters are asymmetric, and their median values tend to decrease. Three categories of NPPs were distinguished: those with the best, worst, and stable practice of the 131I emission. The current global atmospheric release of 129I from all the NPPs in the world is estimated at 0.8 kBq year−1. With an increase in the total installed NPP capacity to 632 GW, the global release of 129I from the NPP emissions will increase to 1.4 kBq year−1, which is two times lower than the rate of natural production of this nuclide from atmospheric Xe isotopes under the action of cosmic rays. Based on the measurements performed at separate Russian NPPs, the contribution of the aerosol and gaseous iodine forms to the total volume activity of the released iodine isotopes was determined. Under the conditions of normal NPP operation, gaseous iodine compounds make the prevalent contribution to the radioiodine emissions (65–85%). [ABSTRACT FROM AUTHOR]

Intense new particle formation (NPF) events were observed in the coastal atmosphere during algae growth and farming season at Xiangshan gulf of the east China coast. High nucleation-mode iodine concentrations measured by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) confirmed that the NPF events were induced by iodine species. Our study provides important information on iodine speciation, size distributions, and its role in NPF in the context of heavy air pollution in China's coastal areas. For the first time, we identified 5 inorganic iodine species, 45 organic iodine compounds (35 molecular formulas), and a group of iodide–organic adducts in aerosols. The concentrations and size distributions of iodine species down to 10 nm were measured during the iodine-induced NPF, continental NPF, and non-NPF days at the coastal site and compared to those at an inland site. The iodine in the above four aerosol sample types were characterized by iodate, aromatic iodine compounds, iodoacetic acid or iodopropenoic acid, and iodide–organic adducts, respectively. Iodide and organic iodine compounds were found in the nucleation-mode particles; however, it is still not clear whether they contributed to nucleation or just new particle growth. Wild algae, as well as farmed algae, could be an important NPF source in China's coastal areas. [ABSTRACT FROM AUTHOR]

The preparation of binary tungsten iodides by the reaction of elements is intrinsically difficult because most compounds are only stable at temperatures where the reaction rates between elemental tungsten and iodine are too low. Therefore, other preparative procedures have to be developed. Two synthetic methods have previously been reported for binary tungsten iodides: halide exchange reactions starting from tungsten chloride, and the reaction of tungsten hexacarbonyl with elemental iodine. These two methods have lead to the discovery of a number of binary tungsten iodide compounds. However, how many compounds can be expected in a binary sytem? A recently developed synthetic method has opened Pandora's box, leading to the discovery of a tremendous number of new binary tungsten iodide compounds with structures which have never been seen before in metal halide chemistry. The formation of binary tungsten iodides depends on a subtle interplay of pressure and temperature conditions as can be monitored by thermal scanning under variable I2 partial pressures. More than twenty binary tungsten iodide compounds with trigonal, tetrahedral, square pyramidal, and octahedral cluster cores are summarized in this review with their formation conditions, crystal structures, and transformation reactions. These preparative advances open new frontiers in metal halide chemistry and give an impact to the chemistry of octahedral [W6I8]4+ cluster compounds which can serve as powerful phosphorescent materials and singlet oxygen generators. [ABSTRACT FROM AUTHOR]

There are limited and inconsistent data suggesting that mild iodine deficiency in pregnancy might be associated with poorer developmental outcomes in children. Between 2011 and 2015, we conducted a prospective cohort study in Australia examining the relationship between maternal iodine intake in pregnancy and childhood neurodevelopment, assessed using Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III), in 699 children at 18 months. Maternal iodine intake and urinary iodine concentration (UIC) were assessed at study entry (<20 weeks' gestation) and at 28 weeks' gestation. Maternal iodine intake in the lowest (<220 μg/day) or highest (≥391 μg/day) quartile was associated with lower cognitive, language, and motor scores (mean differences ranged from 2.4 (95% confidence interval (CI): 0.01, 4.8) to 7.0 (95% CI: 2.8, 11.1) points lower) and higher odds (odds ratios ranged from 2.7 (95% CI: 1.3, 5.6) to 2.8 (95% CI: 1.3, 5.7)) of cognitive developmental delay (Bayley-III score <85) compared with mothers with an iodine intake in the middle quartiles. There was no association between UIC in pregnancy and Bayley-III outcomes regardless of whether UIC and the outcomes were analyzed as continuous or categorical variables. Both low and high iodine intakes in pregnancy were associated with poorer childhood neurodevelopment in this iodine-sufficient population. [ABSTRACT FROM AUTHOR]

Abstract Sulfur-doped cobalt oxide (S-Co 3 O 4) crystals exhibit excellent catalytic activities towards multiple useful reactions, however, the impact of the structural properties on the resultant catalytic activities has been overlooked in the past. We demonstrate a facile vapor-phase hydrothermal (VPH) doping approach to effectively create electrocatalytically active surface sulfur species on the chemical bath deposited polycrystalline Co 3 O 4 nanowires for iodine reduction reaction (IRR). The dye-sensitized solar cells (DSSCs) equipped with the S-Co 3 O 4 nanowire film as the counter electrode (CE) achieve a best energy conversion efficiency of 6.78%, which is comparable to those of DSSCs with commercial Pt CE (7.36%). The impact of film structure, VPH temperature and VPH duration on the resultant structures as well as the electrocatalytic activities has been comprehensively studied. More importantly, our results manifest a close correlation between the surface sulfur dopant level and the key electrocatalytic activity indicators. The VPH approach could be further extended to the fabrication of low-cost, high-performance nanomaterials for energy conversion applications. Highlights • S-Co 3 O 4 films prepared via VPH approach show excellent activities towards IRR. • Best activity is achieved by balancing structural integrity and S dopant density. • A close correlation of activities with dopant levels has been confirmed. [ABSTRACT FROM AUTHOR]

In recent years, a plethora of synthetic methods that employ hypervalent iodine compounds donating an atom or a group of atoms to an acceptor molecule have been developed. Several of these transformations utilize organocatalysis, which complements well the economic and environmental advantages offered by iodine reagents. This short review provides a systematic survey of the organocatalytic approaches that have been used to promote group transfer from hypervalent iodine species. It covers both the reactions in which an organocatalyst is applied to activate the acceptor, as well as those that exploit the organocatalytic activation of the hypervalent iodine reagent itself. 1 Introduction 2 Organocatalytic Activation of Acceptor 2.1 Amine Catalysis via Enamine and Unsaturated Iminium Formation 2.2 NHC Catalysis via Acyl Anion Equivalent and Enolate Formation 2.3 Chiral Cation Directed Catalysis and Brønsted Base Catalysis via Pairing with Stabilized Enolates 3 Organocatalytic Activation of Hypervalent Iodine Reagent 3.1 Brønsted and Lewis Acid Catalysis 3.2 Lewis Base Catalysis 3.3 Radical Reactions with Organic Promoters and Catalysts 4 Summary and Outlook. [ABSTRACT FROM AUTHOR]

Aim: To assess and compare the cytotoxic potential of Chlorhexidine, Listerine and Povidone -Iodine antimicrobial agents on Chinese hamster lung fibroblast V79 cells. Materials and Method: Chlorhexidine (0.2%), Listerine, Povidone iodine were diluted with DMEM medium under sterile conditions to obtain the required concentration. V79 cells were used for the experimental procedures. The cells were cultured in DMEM media supplemented with 10% FBS and 1% Gentamycin at 370C in a humidified 5% CO2 incubator. For all the assays, cells were maintained at 80-90% confluency in T-25 cm2 flasks and used as per requirement. V79 cells were seeded onto 96 well plates at a density of 104 cells per well and allowed to incubate overnight at 37 0C in 5% CO2incubator. The following day the cells were treated with different concentrations of Betadine, Hexidine and Listerine for 12, 24 and 48 hours. Following the treatments, the drug containing media was discarded and 100µl of freshly prepared MTT stock prepared in DMEM media was added in to each well and the plates were incubated at 370C in 5% CO2 incubator for 4 hours. Viability was determined by the ability of the cells to reduce MTT, a water soluble tetrazolium dye to produce violet crystals of formazan. Formazan crystals formed were solubilized by the addition of 100µl of (Di Methyl Sulfoxide). Optical density which is directly proportional to cell viability, was measured at 540nm using a multi well spectrophotometer. Viability curves were plotted using origin. Percentage cell viability was obtained using the formula given below: Percentage viability= [(OD Test - OD Blank)/(OD Control - OD Blank)] *100. Results: V79 cells treated with serially diluted test compounds showed a decrease in cellular viability in a concentration as well as time dependent manner. Hexidine exhibited maximum toxic effect when compared to Listerine and Betadine; betadine possessing the least toxic nature as obvious by the IC50 values for different time durations. Conclusion: Chlorhexidine was found to be most toxic when compared to Listerine and Povidone iodine. Povidone iodine being the least toxic amongst the three mouth rinse. All the compounds exhibited toxic effect in a dose dependent as well as time dependent manner. The result of this study showed that all three given mouth rinses caused V79 proliferation inhibition. [ABSTRACT FROM AUTHOR]

Describes measurements of the electric dipole moment of iodine chloride (ICl) A and X states. Deduction of measurements from a Doppler free laser induced fluorescence spectroscopy of the A-X transition; Development of a model of the spectra; Inversion of the vibrational dependence of the A state dipole moment to get its dependence with the internuclear distance r.

The laser-induced fluorescence spectrum in ICl of the (2’–0‘) vibrational band in the B 3Π0+–X 1Σ+ electronic system has been measured as a function of the electric field strength up to 32.5 kV/cm. Field-induced intensity measurements on I35Cl have been used to determine the magnitude and sign of the electric dipole moment μB in the B state relative to the magnitude and sign of the moment μX in the X state. From the intensity ratio of the field-induced line Q(0) to the allowed Stark component P(1,0), which has the same upper state, it was found that μB/μX=+(0.888±0.051). The positive sign indicates that the polarity is the same in the B and the X states. Intensity ratio measurements for Q(0) to R(5) and for Q(1) to R(5) yield similar (but less precise) results. In order to test this first application of the method to excited electronic states, Stark shift measurements were carried out on a number of P-branch Stark components. It was found for I35Cl that |μB/μX|=(0.8984±0.0036), in good agreement with the intensity measurements. The corresponding determination for I37Cl is that |μB/μX|=(0.900±0.014). The present results are in agreement with those obtained earlier from studies of the absorption spectrum by Watanabe et al. [Jpn. J. Appl. Phys. 31, 901 (1992)]. [ABSTRACT FROM AUTHOR]

Advances in the time propagation of multidimensional wave packets are exploited to present the A-band photodissociation dynamics of methyl iodide for five active vibrational modes on the three relevant excited ab initio potential surfaces. The five modes considered represent all of the experimentally observed dynamical activity. The only modes neglected are the asymmetric C–H stretch and the asymmetric deformation of the methyl group. The kinetic energy operator corresponding to these five degrees of freedom is derived. The fully quantum mechanical calculation was implemented upon grids using 2880 distinct time-dependent configurations, determined by the multiconfigurational time-dependent Hartree algorithm, for each electronic state. All of the currently known experimental results regarding the umbrella vibration, symmetric C–H stretching vibration, perpendicular rotation, and parallel rotation of the photodissociated methyl radical fragment are well reproduced. The full wavelength dependence of all of these quantities is determined. The wavelength dependence of the energy deposited into translational, vibrational, and rotational motion is also given. The time evolution of the modes is presented in the context of correlated motion and its effect upon the dissociative process. Many of the details of the dynamics inherent to the conically intersecting nature of the excited surfaces is delineated. In particular it is shown that the Jahn–Teller distortion of the 1Q1 state is irrelevant in contributing to the perpendicular character of resonance Raman depolarization ratios. Results are compared and contrasted to previous calculations employing the collinear pseudotriatomic model with optimized empirical surfaces or the bent pseudotriatomic model with the same ab initio surfaces. [ABSTRACT FROM AUTHOR]