75-44-5

Halometal carbonyls of gold, palladium, and platinum catalyze the formation of COCl2 from carbon monoxide and dichlorine at atmospheric pressure and room temperature under exclusion of light. Semiquantitative data show that the catalytic efficiency in this homogeneous process is Au > Pd > Pt. Attack at the carbonyl carbon of soluble halo-carbonyl complexes by coordinated chloride or by dichlorine to give unstable M-C(O)-Cl groupings is believed to be operative in these processes.

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Air stripping is an effective and economical process for removing volatile organic chemicals (VOCs) from contaminated water sources. However the air stripping process simply transfers the contaminants from the water to the air phase where they may continue to pose an environmental problem. In this study, the use of ultraviolet light (u.v.) photooxidation for treating the off gas from air stripping is examined. Subsequent papers will address linking u.v. photooxidation with air stripping in a closed loop stripping process. Fundamental studies are conducted to characterize the kinetics of the gas phase photooxidation of five volatile chlorinated alkanes and alkenes under different operating conditions. - Keywords: u.v.; volatile organic compounds; photooxidation; kinetics; gas phase; water treatment

In situ solid-state NMR methodologies have been employed to investigate the photocatalytic oxidation of trichloroethylene (TCE) over two TiO2-based catalysts, Degussa P-25 powder and a monolayer TiO2 catalyst dispersed on porous Vycor glass. 13C magic angle spinning (MAS) experiments reveal that similar reaction intermediates form on the surfaces of both catalysts. Long- lived intermediates, including dichloroacetyl chloride (Cl2HCCOC1, DCAC), carbon monoxide, and pentachloroethane and final products CO2, phosgene (Cl2CO), and HCl were observed under dry conditions. The presence of molecular oxygen was found to be essential for TCE photooxidation to proceed. Adsorbed water was found to greatly reduce the formation of phosgene. The formation of surface-bound dichloroacetate and trichloroacetate species was observed and identified via 13C cross polarization MAS experiments. Dichloroacetate, which forms from mobile DCAC, appears to be bound to the nonirradiated surfaces of the powdered TiO2 catalysts and further degradation was not possible. Formation of di- and trichloroacetate also takes place on the TiO2/PVG catalyst in the absence of light; however, their concentrations are low. Degradation studies of these surface-bound species indicate that the photooxidation of dichloroacetate, is slow and results in the formation of phosgene and CO2, while trichloroacetate remains resistive to degradation on the TiO2/PVG catalyst. Our results also indicate that the formation of DCAC and phosgene seems to be a general result of TCE degradation which is not limited to TiO2 photocatalysis but instead may be more characteristic of the types of initiating species which are formed by UV irradiation. However, the TiO2 surface is the most effective in terms of the observed initial rates of degradation.

Reaction of carbon tetrachloride with aqueous hydrogen peroxide in the presence of anhydrous iron(III) chloride was studied. Optimal conditions for the preparation of phosgene were found on the basis of analysis of the kinetic data and mechanism of the process. The reaction rate and yield (the latter reaching 95% in the stationary mode) are determined mainly by the amount of the heterogeneous catalyst. According to the experimental data, the reaction follows a radical mechanism.

A new flow-through system for the production of [11C]phosgene, a versatile labelling agent in radiochemistry for PET, is described. Cyclotron-produced [11C]CH4 is mixed with Cl2 and converted into [11C]CCl4 by passing the mixture through an empty quartz tube at 510 °C. The outflow is directed through a Sb-filled guard that takes out Cl2 and then, without intentional O2 addition, through a second empty quartz tube at 750 °C, giving rise to [11C]phosgene in 30-35% radiochemical yield.

Active sites in carbon-catalyzed phosgene synthesis from gaseous CO and Cl2 have been identified using C60 fullerene as a model catalyst. The carbon atoms distorted from sp2 coordination in non-planar carbon units are concluded to generate active Cl2. Experiments and density functional theory calculations indicate the formation of a surface-bound [C60?Cl2] chlorine species with radical character as key intermediate during phosgene formation. It reacts rapidly with physisorbed CO in a two-step Eley-Rideal-type mechanism.

Scanning tunneling microscopy (STM) and low energy electron diffraction (LEED) were used to study the degradation of CCl4 on the reduced selvedge of a natural single crystal α-Fe2O3(0001) surface in ultrahigh vacuum. Before exposure to CCl4, STM images indicate that approximately 85% of the reduced surface exhibits a Fe 3O4(111) 2×2 termination, while the remaining 15% is terminated by 1×1 and superstructure phases. Images obtained after room temperature dosing with CCl4 and subsequent flashing to 600 K reveal that chlorine atoms are adsorbed only on surface regions with the Fe 3O4(111) 2×2 termination, not on 1×1 and superstructure regions. Chlorine atoms from dissociative adsorption of CCl 4 are observed to occupy two distinct positions located atop lattice protrusions and in threefold oxygen vacancy sites. However, in companion chemical labeling experiments, chlorine atoms provided by room temperature, dissociative Cl2 adsorption on this surface are found to occupy sites atop lattice protrusions exclusively. The clear dissimilarity in STM feature shape and brightness at the two distinct chlorine adsorption sites arising from CCl4 dissociation as well as the results of the Cl 2 chemical labeling experiments are best explained via reactions on a Fe3O4(111) 2×2 selvedge terminated by a 1/4 monolayer of tetrahedrally coordinated iron atoms. On this surface, adsorption atop an iron atom occurs for both the CCl4 and Cl2 dissociative reactions. A second adsorption site, assigned as binding to second layer iron atoms left exposed following surface oxygen atom abstraction resulting in the formation of phosgene (COCl2), only appears in the case of reaction with CCl4. The reaction mechanism and active site requirements for CCl4 degradation on iron oxide surfaces are discussed in light of this evidence and in the context of our previously reported results from Auger electron spectroscopy (AES), LEED, temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy studies.

Unactivated MCM-41 mesoporous silica catalyzes the photodecomposition of chloroform to phosgene and hydrogen chloride under near-UV (λ > 360 nm) irradiation. The rate of photodecomposition increases toward an asymptotic limit as the O2 partial pressure is increased. Deuterochloroform does not decompose under the same experimental conditions. Low concentrations of both cyclohexane and ethanol quench the photodecomposition, whereas water, up to its solubility limit, does not. Dissolved tetraalkylammonium salts suppress photodecomposition. The data are consistent with a mechanism in which light absorption by an SiO2 defect yields an electron-deficient oxygen atom, which then abstracts hydrogen from chloroform. The resulting CCl 3 radicals react with oxygen to form a peroxy radical that decomposes, eventually yielding phosgene and hydrogen chloride. Unmodified MCM-41 silica catalyzes the photodecomposition of chloroform under near-UV irradiation. It is proposed that decomposition is initiated through hydrogen abstraction from chloroform at a photoactive SiO2 defect site.

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The photochemically induced reactions of a dihalogen, XY, with CO isolated together in an Ar matrix at about 15 K lead to the formation of carbonyl dihalide molecules XC(O)Y, where X and Y may be the same or different halogen atoms, Cl, Br, or I. In addition to the known compounds OCCI2, OCBr2, and BrC(O)Cl, the carbonyl iodide chloride, IC(0)Cl, and carbonyl iodide bromide, IC(O)C, compounds have thus been identified for the first time as products of the reactions involving ICl and IBr, respectively. The first product to be formed in reactions with Cl2, BrCl, or ICI is the CICO radical, which reacts subsequently with a second halogen atom to give the corresponding carbonyl dihalide [OCCI2, BrC(O)Cl, or IC(O)Cl]. The analogous reaction with Br2 affords, in low yield, the unusually weakly bound BrCO radical, better described as a van der Waals complex, Br...CO. The changes have been followed and the products characterized experimentally by their infrared spectra, and the spectra have been analyzed in light of the results afforded by ab initio (Hartree-Fock and Moeller-Plesset second-order) and density functional theory calculations.

New, or improved, syntheses of phosgene, carbonyl bromide chloride and carbonyl bromide fluoride have been elaborated. The NMR (13C, 19F and 17O) and electron impact mass spectra were recorded for COX2 (X = F, C

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An improved procedure, three-step reaction cycle procedure, for the continuous preparation of phosgene from CO, air and HCl catalyzed by CuCl2 was reported for the first time. The corresponding catalytic mechanism of each step was preliminarily disclosed with the powder X-ray diffraction (XRD) analysis: the first step is the oxychlorination of CO to phosgene and simultaneous reduction of CuCl2 to CuCl; the second step is the oxidation of CuCl with air to Cu2OCl2, and the third step is the neutralization of Cu2OCl2 with HCl to CuCl2. The regeneration of catalyst consists of steps 2 and 3, which is called the two-step regeneration of catalyst. The no-simultaneous existence of Cu (I) chloride and water in this three-step reaction procedure prevented effectively copper (I) chloride from the disproportionation. The influence of regeneration conditions, including reaction time, pressure of air or HCl on morphologies and recovery degree of catalyst were investigated and discussed. The degree of recovery for the single-run yield and cumulative yield of phosgene from the two-step regenerated oxychlorination agent can reach, respectively, 87.0% and 97.0% whereas the single-run yield and cumulative yield of phosgene with the one-step regenerated catalyst only can be recovered to 58.8% and 80.5%, respectively. The two-step regeneration method also can result in a higher dispersion of CuCl2/KCl on silica gel than that of the one-step regeneration. These results not only can offer a quite promising potential for the industrial use, but also can promote our deeply understanding of this important industrial reaction.

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The photolysis of chloropicrin (CCl3NO2) was investigated in Ar and N2 cryogenic matrices. The extent of reaction was monitored using FT-IR spectroscopy. Phosgene and nitrosyl chloride were the observed photoproducts at all wavelengths investigated (220, 251, 313, 365, and 405 nm). When the photolysis was performed with 220, 251, or 313 nm light, two additional bands were also observed. These bands have been assigned to CCl3ONO. Chloropicrin was also photolyzed in the presence of O2 and 18O2. 18O-labeled photoproducts were not detected in cryogenic matrices.

Trichloroethylene in solution with air is oxidized rapidly in the presence of irradiated titanium dioxide.Dichloroacetyl chloride (DCAC), which is formed as an intermediate during the trichloroethylene reaction, also undergoes photocatalytic oxidation.This paper describes the kinetics of these reactions and how operating conditions influence the observed reaction rates.Annular photocatalytic reactors with thin films of titanium dioxide catalyst were used to make kinetic measurements.Observations of the reaction rate of trichloroethylene were made while varying parameters such as catalyst loading, feed flow rate, feed composition, and ultraviolet light energy.The observed reaction rates are higher by several orders of magnitude than those previously reported in the literature, and an expression for the prediction of rate as a function of reactant partial pressure is provided.The rate of reaction of the DCAC intermediate is also discussed.Air is shown to be an optimum oxidant, and an optimum humidity is established.The reaction is shown to proceed indefinitely under dry conditions, supporting the existence of a chlorine radical propagated surface reaction.

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The dichloromethyl peroxyl radical (CHCl2OO?) and its deuterated analog formed in the reaction of the corresponding dichloromethyl radicals with O2 were studied by matrix IR spectroscopy. Dichloromethyl radicals are genera

Porous titanium dioxide pellets modified with copper(II) ion (Cu-TiO2) were synthesized by sol-gel method with dialysis for photocatalytic degradation of gaseous trichloroethylene (TCE) under visible light (VL) irradiation. TCE was completely degraded by passing the gas stream (mole fractions of oxygen and TCE were 0.2 and 1.75 × 10?4, respectively) at the flow rate of 25 mL min?1 through 0.2 g of the Cu-TiO2 pellets (Cu content: 0.1 atom%) calcined at 200 °C. TCE was converted mainly to carbon dioxide, dichloroacetic acid (DCAA), and inorganic chlorine species. Relatively small quantities of pentachloroethane (PCA) and trichloroacetaldehyde (TCAH) were detected as products on the Cu-TiO2 surface. Comparison with porous TiO2 pellets under ultraviolet irradiation revealed that more chlorinated products and less carbon dioxide were formed on Cu-TiO2 under VL irradiation. The mineralization of TCE to carbon dioxide was calculated to be only ca. 30.0%. It is noted that DCAA, PCA and TCAH were accumulated on the surface and were extracted with ethyl acetate. The porous Cu-TiO2 pellets show promise as the photocatalyst acting under VL irradiation for converting TCE gas to chlorinated compounds which can be used in industries.

Phosgene is widely used in organic synthesis owing to its high reactivity, utility, and cost efficiency. However, the use of phosgene in batch processes on the industrial scale is challenging owing to its toxicity. An effective method to minimize reaction volumes and mitigate the safety risks associated with hazardous chemicals is the use of flow reactors. Consequently, we have established a flow reaction system using triphosgene and tributylamine, which affords a homogeneous reaction that avoids clogging issues. In addition, we have demonstrated that this methodology can be applied to a wide variety of phosgene reactions, including the preparation of pharmaceutical intermediates, in good to excellent yields.

A fluorescent probe Cou - Bu and its preparation and application of ozone in the detection. The invention provides a can be used for selectively detecting ozone molecules of the fluorescent probe. The main synthetic method is as follows: 7 - amino - 4 - methyl coumarin with triphosgene reaction to obtain the acyl chloride, generated product also and 3 - butene - 1 - ol to undergo esterification reaction, the final generation structure is Compound; under the action of the ozone molecules, generating 7 - amino - 4 - methyl coumarin, by using the difference between the front and the rear of the fluorescent reaction to the selectivity of the ozone molecule detection.

Lactones, cyclic esters of hydroxycarboxylic acids, are interesting biofuel candidates as they can be made from cellulosic biomass and have favorable physical and chemical properties for distribution and use. The reactions of γ-valerolactone (GVL), γ-crotonolactone (2(5H)-F), and α-methyl-γ-crotonolactone (3M-2(5H)-F) with Cl, OD, and O3 were investigated in a static chamber at 700 Torr and 298 ± 2 K. The relative rate method was used to determine kGVL+Cl = (4.56 ± 0.51) × 10-11, kGVL+OD = (2.94 ± 0.41) × 10-11, k2(5H)-F+Cl = (2.94 ± 0.41) × 10-11, k2(5H)-F+OD = (4.06 ± 0.073) × 10-12, k3M-2(5H)-F+Cl = (16.1 ± 1.8) × 10-11, and k3M-2(5H)-F+OD = (12.6 ± 0.52) × 10-12, all rate coefficients in units of cm3 molecule-1 s-1. An absolute rate method was used to determine k2(5H)-F+O3 = (6.73 ± 0.18) × 10-20 and k3M-2(5H)-F+O3 = (5.42 ± 1.23) × 10-19 in units of cm3 molecule-1 s-1. Products were identified for reactions of the lactones with Cl. In the presence of O2 the products are formic acid (HCOOH), formyl chloride (CHClO), and phosgene (CCl2O), and also maleic anhydride (C2H2(CO)2O) for 2(5H)-F. In addition both reactions produced a number of unidentified products that likely belong to molecules with the ring-structure intact. A review of literature data for reactions of other furans show that the reactivity of the lactones are generally lower compared to that of corresponding compounds without the carbonyl group.

A method of making an amino acid triisocyanate is provided, the method comprising reacting an amino acid trihydrochloride with phosgene to form the amino acid triisocyanate. In some embodiments, the amino acid trihydrochloride comprises lysine ester trihydrochloride salt and the amino acid triisocyanate comprises lysine ester triisocyanate. In some embodiments, there is a lysine ester triisocyanate having a purity of at least about 98%, the lysine ester triisocyanate having a structure resulting from reacting lysine ester trihydrochloride salt with phosgene to form the lysine ester triisocyanate. These lysine ester triisocyanates can be used to make biodegradable polyurethanes.

Phosgene and its analogs are greatly harmful to the public health, environmental safety and homeland security as widely used industrial substances with extremely high toxicity. In order to rapidly evaluate the emergency risk caused by these chemicals, a new highly sensitive method based on surface-enhanced Raman spectroscopy (SERS) technique for measurement of phosgene agents was developed for the first time. Coupled with a chemical transformation approach, the highly toxic phosgene was conveniently converted to a SERS-sensitive probe, i.e. iodine (I2), with low toxicity or non-toxicity. The characteristic SERS peak in 459 cm-1 was used for quantitation and was presumed as a formation of triiodide anion (I3-), which was induced in an iodide (I-)-aggregation Au NPs system. The total measurement can be completed in ~20 min with the limits of detection of ~60 μg/l (phosgene) and ~30 μg/l (diphosgene), respectively, on a portable Raman spectrometer. This work is the first report of SERS measurement on phosgene and diphosgene in a quantitative level. This method is expected to meet the requirements of on-site detection of phosgene agents, promote emergency responses and raise more opportunities for the portable SERS applications. A sensitive surface-enhanced Raman spectroscopy method for measurement of phosgene agents with a chemical transformation approach was reported for the first time. With the transformed product iodine, a more stable triiodide anion was formed in an iodide-aggregated Au nanoparticles system appeared as a characteristic ultraviolet-visible absorption peak at 352 nm and a surface-enhanced Raman spectroscopy peak of 459 cm-1. Three phosgene agents exhibit different reaction rates.

The present invention relates to a catalyst for preparing phosgene and a method for preparing phosgene using the catalyst. Said method comprises: modifying the surface of an activated carbon coating/foamed silicon carbide structural catalyst using an alkali metal salt; filling the catalysts having different thickness of the activated carbon coating and different amount of the alkali metal salt in different sections in the axial direction of the multi-tubular reactor of the fixed bed, and preparing phosgene using Cl2 and CO. The radial and axial temperature difference of the catalyst bed is lowered by using the alkali metal salt-modified activated carbon coating/foamed silicon carbide structural catalyst and by segmental filling, so that high temperature of tube wall is obtained in the case of a larger tube diameter, and high quality of steam is obtained stably.

Adsorbent-photocatalyst hybrids based on WO3 and Pt as cocatalyst immobilized on different type of zeolites were prepared. Their performance for the degradation of pollutants under UV and Vis light was analyzed. Two types of zeolites (ZSM-5 and Zeolite Y) with Si/Al ratios ranging between 5 and 280 were selected as hierarchical microporous materials acting as adsorbents. The incorporation of platinum on tungsten oxide was done by means of the photodeposition method. Pt-loaded WO3 was dispersed on the zeolites and subjected to a lyophilization process. Their photocatalytic properties towards the abatement of representative pollutants e.g.; acetic acid, acetaldehyde and trichloroethylene, were analyzed under different operating conditions in batch and continuous flow photoreactors. Raw materials and hybrid photocatalysts were characterized by N2 adsorption-desorption, XRD, UV-vis spectroscopy, XPS and TEM microscopy. The adsorption ability of the photocatalysts towards the selected pollutants was studied under dynamic conditions. The textural properties of the photocatalysts were not the main factor controlling their adsorption ability. The incorporation of WO3-Pt on the zeolite results in Vis light responsive materials. Monoclinic WO3 crystal phase was identify in all zeolitic materials. Large WO3-Pt aggregates were detected on Zeolite Y (ca. 300 nm) with low Si/Al content in contrast with highly disperse phase for ZSM-5 (SiO2/Al2O3 = 280) (ca. 100 nm). All WO3-Pt hybridized zeolites showed photoactivity for the degradation of the studied pollutants under Vis light, improving the performance of bare WO3-Pt. The results shown in this work reveal the influence of the hydrophobicity of the siliceous material for the adsorption of reaction intermediates or byproducts and as a consequence for the determination of the rates of CO2 formation under static conditions. A F(Static) function, dependent of the Si/Al ratio and the BET area, to correlate the difference trend of the amount of CO2 released produced by the hybrid composites, under static and dynamic conditions is proposed.

The currently available β-lactamase inhibitors are insufficient to inhibit the incessantly increasing β-lactamase, and novel β-lactamase inhibitors has been required today for the difficult treatment for bacterial infectious diseases caused by resistant bacteria which produce class C β-lactamase, extended-spectrum β-lactamase (ESBL) belonging to class A and D, or class A KPC-2 decomposing even carbapenem as a last resort for β-lactam antibiotic. A compound represented by the the formula (I), preparation process of the same, β-lactamase inhibitors and method for treating bacterial infectious diseases are provided.

A method of making an amino acid triisocyanate is provided, the method comprising reacting an amino acid trihydrochloride with phosgene to form the amino acid triisocyanate. In some embodiments, the amino acid trihydrochloride comprises lysine ester trihydrochloride salt and the amino acid triisocyanate comprises lysine ester triisocyanate. In some embodiments, there is a lysine ester triisocyanate having a purity of at least about 98%, the lysine ester triisocyanate having a structure resulting from reacting lysine ester trihydrochloride salt with phosgene to form the lysine ester triisocyanate. These lysine ester triisocyanates can be used to make biodegradable polyurethanes.

In some embodiments, a method of making an amino acid trihydrochloride is provided, the method comprising reacting an amino acid monohydrochloride with an alkanolamine to form the amino acid trihydrochloride. In some embodiments, the amino acid monohydrochloride comprises lysine hydrochloride, which is mixed with ethanolamine to form lysine ester trihydrochloride. In some embodiments, there is a lysine ester trihydrochloride salt having a purity of at least about 98%, the lysine ester trihydrochloride salt having a structure resulting from reacting lysine hydrochloride and ethanolamine to form the lysine ester trihydrochloride salt. The lysine ester trihydrochloride can be made in one reaction vessel.

Thermal treatment induces a modification in the nanostructure of carbon nanospheres that generates ordered hemi-fullerene-type graphene shells arranged in a concentric onion-type structure. The catalytic reactivity of these structures is studied in comparison with that of the parent carbon material. The change in the surface reactivity induced by the transformation of the nanostructure, characterized by TEM, XRD, X-ray photoelectron spectroscopy (XPS), Raman, and porosity measurements, is investigated by multipulses of Cl2 in inert gas or in the presence of CH4 or CO. The strained C-C bonds (sp2-type) in the hemi-fullerene-type graphene shells induce unusually strong, but reversible, chemisorption of Cl2 in molecular form. The active species in CH4 and CO chlorination is probably in the radical-like form. Highly strained C-C bonds in the parent carbon materials react irreversibly with Cl2, inhibiting further reaction with CO. In addition, the higher presence of sp3-type defect sites promotes the formation of HCl with deactivation of the reactive C-C sites. The nano-ordering of the hemi-fullerene-type graphene thus reduces the presence of defects and transforms strained C-C bonds, resulting in irreversible chemisorption of Cl2 to catalytic sites able to perform selective chlorination. Tidy up the carbon! CO and CH4 chlorination over hemi-fullerene-type graphene is described. The surface nano-ordering, induced by thermal treatment, transforms strained C-C bond sites resulting in irreversible Cl2 chemisorption to catalytic sites that are able to selectively chlorinate CO and CH4.

A monomer (1) is prepared by reacting a compound (9) with a base or metal to form a metal enolate reagent, and reacting the metal enolate reagent with an acyloxyketone compound (8). A polymer derived from the monomer is used as base resin to formulate a resist composition, which is shelf stable and displays a high dissolution contrast, controlled acid diffusion and low roughness in forming positive pattern via alkaline development and in forming negative pattern via organic solvent development.

Heterogenized on a polystyrene anion exchange resin and in the presence of oxygen, CuCl24 catalyzes the photodecomposition of chloroform at wavelengths above 345 nm with greater efficiency than an equivalent amount in homogeneous solution. The reaction is proposed to proceed in two stages, the first stage yielding CCl4 and HO2 as products, the second consisting of a chain reaction resulting from the CuCl2 4-catalyzed photodissociation of CCl4, yielding phosgene with CCl3 radicals as chain carriers. Photodecomposition is retarded by added Cl, CH3CN, C6H12 or C2H5OH, which is ascribed to the displacement of CHCl3 molecules from the vicinity of the copper by attraction to the polystyrene matrix or to the alkylammonium cation sites.

Provided are an optically active diazabicyclooctane derivative defined by formula (F) below, which is useful as a pharmaceutical intermediate for β-lactamase inhibitor, and a process for preparing the same. In formula (F) above, R1 represents CO2R, CO2M, or CONH2, wherein R represents a methyl group, a tert-butyl group, an allyl group, a benzyl group, or a 2,5-dioxopyrrolidin-1-yl group, and M represents a hydrogen atom, an inorganic cation, or an organic cation; and R2 represents a benzyl group or an allyl group.

The present invention relates to process for the preparation of a cyclic organic carbonate comprising: reacting carbon monoxide and chlorine to form phosgene; reacting phosgene with a di-or polyhydric alcohol containing a vicinal diol moietyto form a reaction mixture comprising the cyclic organic carbonate and hydrogen chloride, which reaction proceeds via a chloroformate intermediate; and oxidizing the hydrogen chloride to chlorine and water, which chlorine is recycled to the phosgene synthesis reaction.

Dissolved hexachlororuthenate(IV) effectively catalyzes the photodecomposition of chloroform to hydrogen chloride and phosgene under near-UV (λ > 345 nm) irradiation, whereby RuCl62- is not itself photocatalytically active, but is photochemically transformed into a species that is active, possibly RuCl5(CHCl3)-. Conversion to a photoactive species during irradiation is consistent with the acceleration of the decomposition rate during the early stages and with the apparent inverse dependence of the decomposition rate on the initial concentration of RuCl62-. The displacement of Cl - by CHCl3 in the coordination sphere to create the photoactive species is consistent with the retardation of photodecomposition by both Cl- and H2O. The much smaller photodecomposition rate in CDCl3 suggests that C-H bond dissociation occurs during the primary photochemical event, which is also consistent with the presence of a CHCl3 molecule in the first coordination sphere. In the presence of RuCl62-, chloroform decomposes under near-UV irradiation to phosgene and hydrogen chloride. The photoactive species is suggested to be RuCl5(CHCl3) -.

Optically active polyurethanes (PUs) with different specific rotations were synthesized using a hydrogen transfer addition polymerization procedure with isocyanate-phenols of varying enantiomeric excess. The optical activities of the PUs were enhanced with an increase in the enantiomeric excess of the monomers. A helical secondary structure in the PUs with a more compact arrangement of the macromolecular backbones facilitated interchain hydrogen bonding, and the infrared emissivity of the corresponding polymers decreased. The results indicated that the level of order and number of hydrogen bonds in the macromolecule played significant roles in controlling the infrared emissivity.

The present invention provides a photolabile protecting group that can be removed by light irradiation under mild conditions. More specifically, the present invention provides a method comprising protecting a reactive functional group (e.g., a hydroxyl group, amino group, carboxyl group, carbonyl group, phosphodiester group, etc.) by the photolabile protecting group, and then removing the photolabile protecting group simply by light irradiation under neutral conditions. The present invention relates to a compound represented by Formula (3): wherein Ar1 is an optionally substituted aromatic or heteroaromatic ring, Ar2 is an optionally substituted aryl or heteroaryl group, X is a leaving group, and n is an integer of 1 or 2; and a method of protecting and deprotecting an amino group etc. using the compound.

The application of two Process Analytical Technology (PAT) tools was studied and implemented for the safe and reliable synthesis of an advanced intermediate (4S,5R-7) of a member of the dihydro-1H-imidazole (1) class of compounds. Real time data were generated using ReactIR to track the complete breakdown of phosgene precursors (2) to phosgene (3) and confirm the absence of these hazardous materials prior to batch transfer operations. In addition, the chiral resolution by crystallization of rac7 was monitored by a Lasentec FBRM probe-based system. Implementation of the latter helped to track the crystallization process to minimize the risk of cocrystallization of undesired isomer 4R,5S-7.

Optically active polyurethanes (LPU and DPU) and racemic polyurethane (RPU) were synthesized by the self-polyaddition of the isocyanate-phenols which derived from the chiral and racemic tyrosine. All of the polymers were characterized by FT-IR, 1H NMR, GPC, UV-Vis spectroscopy, circular dichroism (CD) spectroscopy, TGA and X-ray diffraction (XRD), and the infrared emissivity values were investigated in addition. LPU and DPU were two enantimorphs, they possessed helical configurations and higher degree of hydrogen bondings compared to the RPU which presented random coiled molecular chain. The crystallinity and thermal decomposition temperature of LPU and DPU were higher than that of the RPU due to the more regular secondary structure which facilitate the formation of a large number of inter-chain hydrogen bonds. Consequently, the LPU and DPU exhibited lower infrared emissivity values (8-14 μm), which came down to 0.611 and 0.625.

An experimental investigation on the photolysis of the pesticide chloropicrin, (trichloronitromethane, CCl3NO2), under atmospheric conditions was carried out at the outdoor European Photoreactor, (EUPHORE), in Valencia, Spain. The photodissociation rate coefficient, J obs(CCl3NO2), was determined directly under sunlight conditions during spring and summer months. Values in the range J obs(CCl3NO2) = (3.9-5.1)×10-5 s-1 were obtained, corresponding to photolysis lifetimes of 7.1-5.4 hours. Absorption cross-sections for chloropicrin were determined over the wavelength range 260-370 nm, and together with the measured solar flux intensity, were used to calculate the maximum photolysis rate for chloropicrin, Jmax. Comparison of the observed photolysis rate with the calculated maximum photolysis rate showed that the effective quantum yield of photodissociation, = Jobs(CCl3NO2).J max, was 0.94±0.08. Photolysis of chloropicrin in air or nitrogen gave phosgene as the major carbon-containing product with a yield close to unity based on the loss of chloropicrin. The product yield data were shown to be consistent with a mechanism in which the photolysis channel produces a CCl3 radical and NO2. Kinetic studies on the reactions of hydroxyl radicals and ozone with chloropicrin suggest that, as expected, loss of CCl3NO2 by reaction with these species will be negligible under atmospheric conditions compared to photolysis. Photolysis of chloropicrin in air in the presence of isopropanol gave significant yields of ozone and is consistent with the generation of Cl atoms and NOx following the photodissociation of CCl3NO2. The atmospheric implications of the use of chloropicrin as a pesticide are discussed. by Oldenbourg Wissenschaftsverlag.

The chloride form of the polystyrene-divinylbenzene anion exchange resin Amberlite IRA-900 was found to catalyze the photodecomposition of carbon tetrachloride in ethanol at wavelengths above 350 nm. With sulfate, bromide, and perchlorate as counterions, the resin was inactive. The major products are acetaldehyde, phosgene, chloroform, and hydrogen chloride. The photoreaction is much slower under 1.0 atm O2 than under air, while in deoxygenated solutions it is also much slower and produces no phosgene. Much of the observed behavior can be explained by a model in which the poly(styrene-co- divinylbenzene) matrix absorbs light and transfers energy to CCl4, which undergoes photodissociation, assisted by a chloride ion to stabilize the chlorine atom as Cl2-. Two major reaction channels for the trichloromethyl radicals produced by photodissociation are proposed, one in which CCl3 abstracts hydrogen from ethanol and the other involving addition of O2 to form trichloromethylperoxy radicals.

The present invention relates to a process for manufacturing isocyanates from an amine compound. The process comprises the steps of a) Providing chlorine; b) Providing carbon monoxide; c) Reacting said chlorine and said carbon monoxide for providing phosgene, the carbon monoxide being provided in an adjustable molar excess; d) Providing an amine compound and phosgenating said amine compound using said phosgene thereby providing said isocyanate; the process further comprises adjusting said adjustable molar excess, i.e. the molar excess of carbon monoxide, for adjusting the colour of the isocyanate.

Relative rate method at the temperature of 298 K and pressure of 1013 hPa and GC-MS detection were used for the study of kinetics of the reactions of Cl atoms with H2C=CCl2, cis-ClHC=CHCl, trans-ClHC=CHCl, ClHC=CCl2, and Cl2C=CCl2. The reaction products were identified by FTIR spectroscopy. A mechanism for the atmospheric degradation of chloro-ethenes has been suggested.

Phosgene is quantitatively formed from solid triphosgene in a solvent-free and safe process without any reaction heat, catalyzed by planar N-heterocycles with deactivated imino functions. The rate of phosgene generation is adjustable to the rate of phosgene consumption in the subsequent phosgenation reaction by thermal control, catalyst concentration, and in some cases, specific properties of selected metal phthalocyanines. A thermal runaway reaction of this process is impossible.

The present invention provides a siRNA-encapsulated polymer micelle complex (a polyion complex), which has high monodispersibility and structural stability and is excellent in the ability of delivering siRNA into a cell. The present invention further provides a nucleic acid delivery device, a nucleic acid delivery kit, a pharmaceutical composition and a gene therapy agent, each of which comprises the complex. The polyion complex of the present invention is characterized by comprising: a block copolymer constituted by a polyethylene glycol portion and a polycation portion having a side chain whose terminus is a thiol group; and siRNA.

The application relates to a process for the continuous production of phosgene from chlorine and CO with reduction of the carbon monoxide emission (CO emission).

Bis(chlorocarbonyl)trisulfane, ClC(O)SSSC(O)Cl, was prepared by the reaction of (CH3)2CHOC(S)SC(S)OCH(CH3)2 and SO2Cl2 at 65 °C. The compound was characterized and identified by vibrational

Processes are described which comprise: (a) reacting chlorine with carbon monoxide to form phosgene; (b) reacting the phosgene with at least one organic amine to form at least one isocyanate and hydrogen chloride; (c) separating the hydrogen chloride; (d) oxidizing the hydrogen chloride with oxygen in a gas phase to form additional chlorine; and (e) recycling at least a portion of the additional chlorine to the reaction of the chlorine and the carbon monoxide; wherein the oxidation of the hydrogen chloride is initiated via a high energy source which may be selected from electron-exciting radiation, ionizing radiation, a gas discharge, a plasma, and combinations thereof.

The invention relates to a process for separating hydrogen chloride and phosgene, which comprises bringing a mixture of hydrogen chloride and phosgene into contact with an ionic liquid in which at least part of the hydrogen chloride is dissolved in a step a) and then separating off the hydrogen chloride dissolved in the ionic liquid in a step b).

Carbonyl fluoride, which can also be used as an etching gas, can be prepared by photochemical oxidation of chlorodifluoromethane or trifluoromethane with light, for example with light of a wavelength >=280 nm in the presence of chlorine.

Visible-light-driven TiO2 photocatalysts doped with nitrogen have been prepared as powders and thin films in a cylindrical tubular furnace under a stream of ammonia gas. The photocatalysts thus obtained were found to have a band-gap energy of 2.95 eV. Electron spin resonance (ESR) under irradiation with visible light (λ ≥ 430 nm) afforded the increase in intensity in the visible-light region. The concentration of trapped holes was about fourfold higher than that of trapped electrons. Nitrogendoped TiO 2 has been used to investigate mechanistically the photocatalytic oxidation of trichloroethylene (TCE) under irradiation with visible light (λ ≥ 420 nm). Cl and O radicals, which contribute significantly to the generation of dichloroacetyl chloride (DCAC) in the photocatalytic oxidation of TCE under UV irradiation, were found to be deactivated under irradiation with visible light. As the main by-product. only phosgene was detected in the photocatalytic oxidation of TCE under irradiation with visible light. Thus, the reaction mechanism of TCE photooxidation under irradiation with visible light clearly differs markedly from that under UV irradiation. Based on the results of the present study, we propose a new reaction mechanism and adsorbed species for the photocatalytic oxidation of TCE under irradiation with visible light. The energy band for TiO2 by doping with nitrogen may involve an isolated band above the valence band.

The photolytically induced reactions of a dihalogen XY (= Cl2, ICl, or IBr) with OCS isolated together in an Ar matrix at about 15 K lead to different photoproducts depending on the natures of X and Y. In addition to the known species ClCO, OCCl2, syn-ClC(O)SCl, syn-ClC(O)SSCl, IC(O)Cl, IC(O)Br, and ^n-BrC(O)SBr, syn-iodocarbonylsulfenyl bromide, yyn-IC(O)SBr, has thus been identified for the first time as'a photoproduct of the reactions involving IBr. The first product to be formed in the reactions with Cl 2 or ICI is the C1CO radical which reacts subsequently with halogen or sulfur atoms or other matrix guests to give the corresponding carbonyl dihalide (OCCl2 and IC(O)Cl), syn-ClC(O)SCl or syn-ClC(O)SSCl. The analogous reaction with IBr affords syn-BrC(O)SBr, IC(O)Br, and syn-IC(O)SBr. The changes have been followed, the products characterized experimentally by IR measurements, and the spectra analyzed in the light of the results of appropriate theoretical calculations.

The invention relates to a process for the production of phosgene, in which chlorine and carbon monoxide are reacted in the presence of an activated charcoal catalyst in a shell-and-tube reactor which contains a plurality of reaction tubes and a coolant space surrounding the reaction tubes, in which a) cooling of the reaction tubes is from the outside through the coolant space with water by evaporative cooling, and b) operation of the reaction tubes is at a pressure above the pressure in the coolant space.

Dichlorodifluoromethane (CCl2F2, 1% in He) decomposition with simultaneous halogen fixation by vanadium oxide supported on magnesium oxide was studied at 723 K in a flow apparatus. The pretreatment condition and vanadium loading of supported vanadium oxide samples affected the CCl2F2 decomposition efficiency. Through characterization studies (XRD, IR, Raman, and XPS) and reference experiments, Mg 3(VO4)2 was revealed to be the active species to initiate CCl2F2 decomposition, leading to MgF 2, MgCl2, and CO2 formation. The model experiments also suggested a detailed mechanism that VOCl3 was formed from Mg3(VO4)2 by a reaction with CCl 2F2 or the major intermediate compound CCl4, and that VOCl3 reacted with MgO to regenerate Mg3(VO 4)2 and to promote chlorine fixation as MgCl2.

A process for producing phosgene having low content of carbon tetrachloride is disclosed. The process entails reacting carbon monoxide with chlorine in the presence of elemental carbon, in a reactor. Critically the temperature of the gas stream emerging from the reactor is restricted to 30 to 80° C. and its pressure, measured directly downstream from said reactor is restricted to 120 to 400 kPaabs. The phosgene thus produced has a content of carbon tetrachloride that is less than 150 ppm.

The present invention relates to a process for preparing an organic peroxide and the subsequent use thereof in a (co)polymerization reaction, wherein the process comprises the steps (a), b1 (or b2), (c), (d), and (e), said steps being: (a) the reaction of chlorine with carbon monoxide, (b1) the reaction of phosgene formed in step (a) with one or more alcohols in order to prepare chloroformate, (b2) the reaction of phosgene formed in step (a) with one or more organic acids to prepare acid chloride, optionally in the presence of a catalyst suitable to effect the reaction of phosgene with said one or more organic acids, (c) the reaction of chloroformate, acid chloride, or mixture thereof with (in)organic hydroperoxide and base in an aqueous environment, (d) the transfer of organic peroxide formed in step (c) to a polymerization vessel, and (e) the (co)polymerization of monomer in the polymerization vessel in the presence of one or more organic peroxides transferred in step (d), wherein all of steps (a)-(e) are conducted at one site.

The reaction between nanometer TiO2 and CCl4 in the presence of oxygen has been studied in order to investigate the potential of nanometer TiO2 as a destructive reagent for chlorinated hydrocarbons. Two kinds of nanometer TiO2 of different size were synthesized. The properties of the destructive adsorption of CCl4 over nanometer TiO2 of about 40 nm in size were compared with that over nanometer TiO2 of about 80 nm in size. The reactivity toward CCl4 of nanometer TiO2 of about 40 nm in size was remarkably higher than that of nanometer TiO2 of about 80 nm in size. The products produced included CO2, COCl2, Cl2, titanium oxychloride, TiCl4, carbon, CO and HCl. HCl was a major gaseous product. Hydrogen of HCl came from traces of water in the carrier gas and surface OH groups of TiO2. The formation of TiCl4 made the interaction surface renew so that CCl4 could further interact with the bulk of the particles. TiO2 was regenerated through the exchange of chlorine with oxygen at 550°C in the carrier gas so that larger quantities of CCl4 are decomposed over nanometer TiO2 in the presence of oxygen. A mechanism has been proposed for the destructive adsorption and desorption of CCl4 over nanometer TiO2 in the presence of oxygen.

A rapid, safe, and efficient procedure was developed to synthesize, on a small scale, fluorinated chloroformates often required to perform analytical derivatizations. This new family of agents allows straightforward derivatization of highly polar compounds (with multiple hydroxy, carboxy, and amino substituents) in the aqueous phase, compatible with GC and GC/MS analysis. A goal of this work was to develop a derivatization procedure that would enable the detection and identification of highly polar disinfection by-products in drinking water.

Rate coefficients for the reactions of hydroxyl radicals and chlorine atoms with a series of halogenated acetones of the type CX3COCH 3 (X = H, Cl, F) have been determined using a photolytic relative-rate technique at T = 298 K and at 760 Torr total pressure. The reactions studied and the rate coefficients obtained are shown in the table. Reaction Reaction number Rate coefficient/cm3 molecule-1 s-1 OH + CH3COCH3 → products (1) (2.2 ± 0.5) × 10-13 OH + CH2ClCOCH3 → products (2) (4.2 ± 0.8) × 10-13 OH + CHCl 2COCH3 → products (3) (3.8 ± 0.8) × 10-13 OH + CCl3COCH3 → products (4) (1.5 ± 0.3) × 10-14 OH + CH2FCOCH3 → products (5) (2.1 ± 0.4) × 10-13 OH + CF 3COCH3 → products (6) (6.9 ± 1.3) × 10-15 Cl + CH3COCH3 → products (7) (2.2 ± 0.4) × 10-12 Cl + CH2ClCOCH3 → products (8) (2.0 ± 0.2) × 10-12 Cl + CHCl 2COCH3 → products (9) (1.7 ± 0.3) × 10-13 Cl + CCl3COCH3 → products (10) ( 1. 7 ± 0.3) × 10-14 Cl + CH2FCOCH3 → products (11) (8.2 ± 1.6) × 10-13 Cl + CF 3COCH3 → products (12) (8.0 ± 1.6) × 10-15 The errors quoted reflect an estimate of the absolute uncertainty in the measured rate coefficients of ±20%. For reactions (7)-(12), Fourier transform infrared spectroscopy was used to identify products. Qualitative ultra-violet absorption spectra were also recorded for most of the halogenated species investigated in this study, and have been used together with the kinetic data to derive atmospheric lifetimes for these species.

During direct-photodegradation treatment of trichloroethylene by a low-pressure mercury lamp in a dry air atmosphere, slightly degradable by-products are produced; this production is the most serious issue associated with such treatment. We observed the acceleration of by-products degradation with decrease in an oxygen concentration in a treatment atmosphere.