14700-96-0

Basic information

• Product Name: clorine
• CAS NO: 14700-96-0
• Molecular Weight: 35.453
• Mol File: 14700-96-0.mol
• Article Data: 182

Chemical Properties

• CAS DataBase Reference: clorine(CAS DataBase Reference)
• NIST Chemistry Reference: clorine(14700-96-0)
• EPA Substance Registry System: clorine(14700-96-0)

Safety Data

• Hazardous Substances Data: 14700-96-0(Hazardous Substances Data)

Upstream product

• 56-23-5 tetrachloromethane 
• 127-18-4 1,1,2,2-tetrachloroethylene 
• 74-87-3 methylene chloride 
• 79-01-6 Trichloroethylene 
• 23273-89-4 1,1,1-trichloroethyl radical 
• 75-72-9 chlorotrifluoromethane 
• 75-71-8 Dichlorodifluoromethane 
• 3352-57-6 hydroxyl 
• 14989-30-1 chlorine monoxide 
• 7647-14-5 sodium chloride 
• 7732-18-5 water 
• 7647-01-0 hydrogenchloride 
• 10024-97-2 dinitrogen monoxide 
• 7726-95-6 bromine 

Downstream Products

• 7790-99-0 Iodine monochloride 
• 3352-57-6 hydroxyl 
• 16887-00-6 chloride 
• 7647-01-0 hydrogenchloride 
• 7698-05-7 hydrogen chloride 
• 10102-43-9 nitrogen(II) oxide 
• 7782-50-5 chlorine 
• 2074-87-5 carbon nitride 
• 14989-30-1 chlorine monoxide 
• 10097-32-2 bromine 
• 7647-14-5 sodium chloride 
• 7704-34-9 sulfur 
• 10108-64-2 cadmium(II) chloride 
• 7440-43-9 cadmium 

Relevant articles and documents

Collision energy dependence of the O(1D) + HCl -OH + Cl( 2P) reaction studied by crossed beam scattering and quasiclassical trajectory calculations on ab initio potential energy surfaces

The dynamics of the O(1D) + HCl → OH + Cl(2P) reaction are investigated by a crossed molecular beam ion-imaging method and quasiclassical trajectory calculations on the three ab initio potential energy surfaces, the ground 11A′ and two excited (1 1A″ and 21A′) states. The scattering experiment was carried out at collision energies of 4.2, 4.5, and 6.4 kcal/mol. The observed doubly differential cross sections (DCSs) for the Cl(2P) product exhibit almost no collision energy dependence over this inspected energy range. The nearly forward-backward symmetric DCS indicates that the reaction proceeds predominantly on the ground-state potential energy surface at these energies. Variation of the forward-backward asymmetry with collision energy is interpreted using an osculating complex model. Although the potential energy surfaces obtained by CASSCF-MRCI ab initio calculations exhibit relatively low potential barriers of 1.6 and 6.5 kcal/mol for 1 1A″ and 21A′, respectively, the dynamics calculations indicate that contributions of these excited states are small at the collision energies lower than 15.0 kcal/mol. Theoretical DCSs calculated for the ground-state reaction pathway agree well with the observed ones. These experimental and theoretical results suggest that the titled reaction at collision energies less than 6.5 kcal/mol is predominantly via the ground electronic state.

Photodissociation dynamics of phosgene: New observations by applying a three-dimensional imaging technique

The three-dimensional (3D) momentum vector of single Cl atoms in the uv photodissociation of phosgene was directly observed using the recently developed 3D imaging technique. The previous results as there is the generation of chlorine in the 2P/3/2 electronic ground state as well as in the electronically excited 2P1/2 state, the highly spin selective process with bimodal kinetic energy distribution and the overall decay mechanism as well as the branching ratios were confirmed. The anisotropy parameter β and its speed dependence were observed for the first time.

Primary and secondary dissociation pathways in the ultraviolet photolysis of Cl2O

The photodissociation of dichlorine monoxide (Cl2O) at 308, 248, and 193 nm was studied by photofragment translational energy spectroscopy.The primary channel upon excitation at 308 and 248 nm was Cl-O bond fission with production of ClO + Cl.A fraction of the ClO photoproducts also underwent spontaneous secondary dissociation at 248 nm.The center-of-mass translational energy distribution for the ClO + Cl channel at 248 nm appeared to be bimodal with a high energy component that was similar in shape to the 308 nm distribution and a second, low energy component with a maximum close to the threshold for the 2Cl + O(3P) channel.Observation of a bimodal distribution suggests that two pathways with different dissociation dynamics lead to ClO + Cl products.The high product internal energy of the second component raises the possibility that ClO is formed in a previously unobserved spin-excited state a 4Σ-.Following excitation at 193 nm, a concerted dissociation pathway leading to Cl2 + O was observed in addition to primary Cl-O bond breakage.In both processes, most of the diatomic photofragments were formed with sufficient internal energy that they spontaneously dissociated.The time-of-flight distributions of the Cl2 + O products suggest that these fragments are formed in two different channels Cl2(3Π) + O(3P) and Cl2(X 1Σ) + O(1D).

Measuring gas-phase chlorine atom concentrations: Rate constants for Cl + HN3, CF3I, and C2F5I

A convenient method is reported for the measurement of gas-phase Cl atom concentrations in the 1011-1013 atoms cm-3 range in a flow reactor. The titration reaction with vinyl bromide is used to measure the absolute Cl atom concentration, and the relative Cl atom concentration is monitored by the HCl(ν) infrared emission intensity produced by the reaction of Cl atoms with hydrogen sulfide. A microwave discharge through dilute flows of Cl2, CCl4, CFCl3, and CF2Cl2 in Ar were characterized as sources of Cl atoms in the flow reactor. The elementary rate constants for reaction of Cl atoms with HN3, CF3I, and C2F5I were measured as (1.1 ± 0.3) × 10-12, (5.1 ± 1.5) × 10-13, and (3.9 ± 0.8) × 10-12 cm3 molecule-1 s-1, respectively, at 300 K. These rate constants were obtained after adjustment of the apparent rate constants for secondary reactions.

A laser flash photolysis-resonance fluorescence kinetics study of the reaction Cl(2P) + CH4 -> CH3 + HCl

The technique of laser flash photolysis-resonance fluorescence is employed to study the kinetics of the reaction Cl(2P) + CH4 -> CH3 + HCl over the temperature range 221-375 K.Chlorine atoms are produced by photolysis of Cl2 at 355 nm.At temperatures =1L) and high (klH) methane concentrations.For Cl2/CH4/CCl4/He and Cl2/CH4/Ar reaction mixtures, the bimolecular rate constant (k1) is independet of methane concentration with k1 ca. k1L. k1 and k1L are in good agreement with previous results obtained using the flash photolysis-resonance fluorescence technique while k1H is in good agreement with previous results obtained using the didcharge flow-resonance fluorescence and competitive chlorination techniques.At 298 K the measured bimolecular rate constant is independet of the identity of the chemically inert gases in the reaction mixture and in good agreement with all previous investigations.The low temperature results obtained in this investigation and all previous investigations can be rationalized in terms of a model which assumes that the Cl(2P1/2) state reacts with CH4 much faster than the Cl(2P3/2) state.Extrapolation of this model to higher temperatures, however, is not straightforward.

The photodissociation of ClNO2 in argon and water clusters studied at 235 nm by the REMPI-TOF method

The photodissociation of ClNO2 embedded in argon and water clusters was investigated at 235 nm by detecting the Cl(2P3/2) photofragments with resonance enhanced multiphoton ionization time-of-flight spectroscopy (REMPI-TOF). Under various cluster formation conditions the speed distributions of Cl(2P3/2) were recorded. In contrast to the monomer photolysis only one decay channel was found to be active showing the fragments to be Boltzmann distributed and isotropic. In view of atmospheric chemistry, CINO2 in water clusters is a photolytical source of Cl and NO2 radicals with low translational and internal energy. They are thus less favorable for consecutive reactions than the monomer products.

ESR of matrix isolated bromine atoms produced in the H + Br2 reaction

The products of the H(D) + X2 reaction, where X is Br, Cl, or F, have been trapped in solid argon at 4 K and observed via ESR.With Br2 as reactant the observed spectra are attributed to Br atoms electronically quenched in an axial crystal field.The spectra obtained using the other halogens were not clearly attributable to quenched atoms.The ESR of matrix-isolated Br atoms has not been observed previousls, > but their magnetic properties are similar to those recently observed by Iwasaki, Toriyama, and Muto for I atoms queched in solid xenon.For Br: g = 2.646(1),g = 1.55(1),/A/ = 1937(20)MHz, /A/ = 423(10) MHz, and Q = 100(10) MHz.Comparison was made with crude axial crystal field predictions derived using the magnetic parameters of the gas-phase atoms.

ON THE DECAY OF THE DICHLORIDE ANION Cl2 - IN AQUEOUS SOLUTION.

The decay kinetics of Cl//2** minus , produced by photolysis of chloride ions, has been studied using a flash photolysis technique with conductometric detection. Flash photolysis of Cl** minus ions in acid solutions eventually yields H//2O//2, Cl//2, HClO and H//2. A mechanism is proposed (Fig. 6) consistent with the experimental observations.

Competing dissociation channels in the photolysis of S2Cl2 at 235 nm

The photodissociation of disulfur dichloride at 235 nm was investigated by three-dimensional (3D) imaging of the chlorine product recoil in its ground state and excited spin-orbit state. The resonance increasing muliphoton ionization and time-of-flight techniques were used. The dependence of anisotropy parameter on the fragment recoil velocity was determined due to the technique where the 3D momentum vector of a single reaction product was found.

Kinetics, mechanism, and thermochemistry of the gas phase reaction of atomic chlorine with dimethyl sulfoxide

A laser flash photolysis-resonance fluorescence technique has been employed to study the kinetics of the reaction of chlorine atoms with dimethyl sulfoxide (CH3S(O)CH3; DMSO) as a function of temperature (270-571 K) and pressure (5-500 Torr) in nitrogen bath gas. At T = 296 K and P ≥ 5 Torr, measured rate coefficients increase with increasing pressure. Combining our data with literature values for low-pressure rate coefficients (0.5-3 Torr He) leads to a rate coefficient for the pressure independent H-transfer channel of k1a = 1.45 × 10-11 cm3 molecule -1 s-1 and the following falloff parameters for the pressure-dependent addition channel in N2 bath gas: k1b,0 = 2.53 × 10-28 cm6 molecule-2 s -1; k1b,∞ = 1.17 × 10-10 cm 3 molecule-1 s-1, Fc = 0.503. At the 95% confidence level, both k1a and k1b(P) have estimated accuracies of ±30%. At T > 430 K, where adduct decomposition is fast enough that only the H-transfer pathway is important, measured rate coefficients are independent of pressure (30-100 Torr N2) and increase with increasing temperature. The following Arrhenius expression adequately describes the temperature dependence of the rate coefficients measured at over the range 438-571 K: k1a, = (4.6 ±0.4) × 10-11 exp[-(472 ± 40)/T) cm3 molecule-1 s-1 (uncertainties are 2σ, precision only). When our data at T > 430 K are combined with values for k1a at temperatures of 273-335 K that are obtained by correcting reported low-pressure rate coefficients from discharge flow studies to remove the contribution from the pressure-dependent channel, the following modified Arrhenius expression best describes the derived temperature dependence: k1a = 1.34 × 10-15T1.40 exp(+383/T) cm3 molecule-1 s-1 (273 K ≤ T ≤ 571 K). At temperatures around 330 K, reversible addition is observed, thus allowing equilibrium constants for Cl-DMSO formation and dissociation to be determined. A third-law analysis of the equilibrium data using structural information obtained from electronic structure calculations leads to the following thermochemical parameters for the association reaction: ΔrH298o = -72.8 ±2.9 kJ mol -1, ΔHo0 = -71.5 ±3.3 kJ mol -1, and ΔrS298o = -110.6 ±4.0 J K-1 mol-1. In conjunction with standard enthalpies of formation of Cl and DMSO taken from the literature, the above values for Δrffo lead to the following values for the standard enthalpy of formation of Cl-DMSO: ΔfH298 o = -102.7 ± 4.9 kJ mol-1 and Δ rHo0 = -84.4 ±5.8 kJ mol-1. Uncertainties in the above thermochemical parameters represent estimated accuracy at the 95% confidence level. In agreement with one published theoretical study, electronic structure calculations using density functional theory and G3B3 theory reproduce the experimental adduct bond strength quite well.

Photodissociation of Phosgene on Pd(111) at 193 nm

The UV photodissociation of phosgene (Cl2CO) on Pd(111) has been studied by isothermal mass spectrometry during irradiation and by temperature-programmed desorption and X-ray photoelectron spectroscopy following irradiation.Phosgene, which adsorbs reversibly on Pd(111) at 110 K, undergoes photodissociation when irradiated with 6.4-eV photons, resulting in the evolution of CO and retention of chlorine adatoms.Photolysis rates have been monitored as a function of photon flux and, using polarized light, as a function of incident angle.The initial photodissociation crosssection is (5.3 +/- 0.8) x 10-18 cm2, higher than the gas-phase absorption cross section.The angular response of the photolysis yield is interpreted using a mechanism driven by photoexcited substrate electrons.

Kinetics of the reactions of chlorine atoms with a series of acetates

The kinetics of the reactions of Cl atoms with a series of alkyl acetates were investigated using relative and absolute rate methods in 2-700 Torr of N2 at room temperature. Consistent results were obtained using the two methods. The data from

UV Photolysis of ClOOCl

ClOOCl (ClO dimer) photolysis is believed to dominate the catalytic destruction of polar stratospheric ozone during springtime through the production of atomic chlorine. Decomposition by an alternate pathway to form ClO would not catalyze ozone loss. Molecular beam experiments have demonstrated that photoexcitation of ClOOCl at both 248 and 308 nm leads to dissociation via multiple dynamical pathways, producing ClO + ClO and 2Cl + O2. At 248 nm, both concerted and sequential dissociation to 2Cl + O2 were observed. The primary dissociation channels occurred within a rotational period at both excitation wavelengths. The relative Cl:ClO product yields are 0.88:0.12 and 0.90:0.10 at 248 and 308 nm, respectively. Lower limits on these ratios were determined. These results substantially confirm the importance of ClOOCl photolysis in catalyzing springtime polar ozone depletion.

Kinetics of the Reaction of Cl with ClNO and ClNO2 and the Photochemistry of ClNO2

The room temperature rate constants for the reactions Cl+ClNO (2) and Cl+ClNO2 (4) have been measured by the method of laser flash photolysis/resonance fluorescence.The rate constants obtained are (k2+/-2?)=(1.65+/-0.32)E-11 cm3ssup

Some complexities in the reaction of hydrogen atoms generated in H2 discharge with molecular chlorine

The kinetics of the reaction H + Cl2 → HCl + Cl was studied in the very low-pressure reactor system at 298 K using two different H atom generation sources. No traces of HCl(v) excited product side reaction could be found in the system due to th

Photochemistry of phosgene in the solid phase: State-resolved dissociation dynamics

The translational, rotational, and vibrational state distributions of CO (g) resulting from the single photon photodissociation of Cl2CO in the condensed phase at ～90 K have been determined by time-of-flight (TOF) distribution measurement and resonance-enhanced multiphoton ionization (REMPI) spectroscopy. The TOF distribution of CO (g) is bimodal. Internal state characterization of the slow channel reveals a completely thermalized origin, with a rotational temperature of Trot=88±5 K, which is equal to the translational temperature as well as the substrate temperature. We believe these slow CO molecules originate from photodissociation below the topmost surface of the molecular film and achieve thermal equilibrium with the substrate before escaping into the gas phase. Internal state characterization of the fast channel shows, on the other hand, an energetic origin: at hv=5.0 eV, the rotational distribution, with an overall flux-weighted mean rotational energy of 〈Erot〉=0.12±0.01 eV, is non-Boltzmann and can be approximated by a bimodal distribution with rotational temperatures of 210±40 K at low J″(s) and 2200±300 K at high J″(s); the relative vibrational population is Nv=1/Nv=0=0.33±0.05. Both rotational and translational distributions of fast CO show positive correlation with photon energy. These CO molecules must be promptly ejected into the gas phase, carrying nascent energetic information from the photodissociation reaction on the surface of the molecular film. For electronic excitation events that result in photodissociation, 74% of the excess excitation energy is distributed in the translational and internal motions of products (CO and Cl); only 26% of the available energy is converted to motions of surrounding molecules.

Selective C-H halogenation over hydroxylation by non-heme iron(iv)-oxo

Non-heme iron based halogenase enzymes promote selective halogenation of the sp3-C-H bond through iron(iv)-oxo-halide active species. During halogenation, competitive hydroxylation can be prevented completely in enzymatic systems. However, synthetic iron(iv)-oxo-halide intermediates often result in a mixture of halogenation and hydroxylation products. In this report, we have developed a new synthetic strategy by employing non-heme iron based complexes for selective sp3-C-H halogenation by overriding hydroxylation. A room temperature stable, iron(iv)-oxo complex, [Fe(2PyN2Q)(O)]2+ was directed for hydrogen atom abstraction (HAA) from aliphatic substrates and the iron(ii)-halide [FeII(2PyN2Q)(X)]+ (X, halogen) was exploited in conjunction to deliver the halogen atom to the ensuing carbon centered radical. Despite iron(iv)-oxo being an effective promoter of hydroxylation of aliphatic substrates, the perfect interplay of HAA and halogen atom transfer in this work leads to the halogenation product selectively by diverting the hydroxylation pathway. Experimental studies outline the mechanistic details of the iron(iv)-oxo mediated halogenation reactions. A kinetic isotope study between PhCH3 and C6D5CD3 showed a value of 13.5 that supports the initial HAA step as the RDS during halogenation. Successful implementation of this new strategy led to the establishment of a functional mimic of non-heme halogenase enzymes with an excellent selectivity for halogenation over hydroxylation. Detailed theoretical studies based on density functional methods reveal how the small difference in the ligand design leads to a large difference in the electronic structure of the [Fe(2PyN2Q)(O)]2+ species. Both experimental and computational studies suggest that the halide rebound process of the cage escaped radical with iron(iii)-halide is energetically favorable compared to iron(iii)-hydroxide and it brings in selective formation of halogenation products over hydroxylation.

Measuring the rate constant of the reaction between chlorine atoms and CHF2Br by Cl atom resonance fluorescence

The rate constant of the reaction between Cl atoms and CHF2Br has been measured by chlorine atom resonance fluorescence in a flow reactor at temperatures of 295–368 K and a pressure of ~1.5 Torr. Lining the inner surface of the reactor with F-32L fluoroplastic makes the rate of the heterogeneous loss of chlorine atoms very low (khet ≤ 5 s–1). The rate constant of the reaction is given by the formula k = (4.23 ± 0.13) × 10–12e(–15.56 ± 1.58)/RT cm3 molecule–1 s–1 (with the activation energy in kJ/mol units). The possible role of this reaction in the extinguishing of fires producing high concentrations of chlorine atoms is discussed.

Atmospheric chemistry of CF3CH2OCH3: Reaction with chlorine atoms and OH radicals, kinetics, degradation mechanism and global warming potential

FTIR smog chamber techniques were used to measure k(Cl + CF 3CH2OCH3) = (2.28 ± 0.44) × 10-11 and k(OH + CF3CH2OCH3) = (4.9 ± 1.3) × 10-13 cm3 molecule-1 s-1 in 700 Torr total pressure of air at 296 ± 2 K. The atmospheric lifetime of CF3CH2OCH3 is estimated at 25 days. Reaction of Cl atoms with CF3CH2OCH 3 proceeds 79 ± 4% at the CH3 group and 22 ± 2% at the CH2 group. Reaction with OH radicals proceeds 55 ± 5% at the CH3 group yielding CF3CH2OCHO and 45 ± 5% at the CH2 group yielding COF2 and CH 3OCHO as primary oxidation products. The infrared spectrum of CF 3CH(O)OCH3 was measured and a global warming potential GWP100 = 8 was estimated. The atmospheric chemistry and environmental impact of CF3CH2OCH3 is discussed in context of the use of hydrofluoroethers as CFC substitutes.