Dibromochloromethane (124-48-1) Physical and Chemical Properties
Dibromochloromethane
Dense halogenated methan e used as a reagent and analytical reference in specialty synthesis and laboratory workflows.
| CAS Number | 124-48-1 |
| Family | Halogenated aliphatics |
| Typical Form | Colorless to pale yellow liquid |
| Common Grades | EP, JP, USP |
Dibromochloromethane is a halogenated aliphatic (haloform) of the general structural class of trihalomethanes. Its molecular formula is \( \ce{CHBr2Cl} \), a single-carbon, tetrahalogenated methane derivative in which two bromine atoms and one chlorine atom are bound to the central carbon. Electronic structure is dominated by the large, polarizable halogen substituents; the molecule lacks heteroatom lone-pair donors or acceptors suitable for classical hydrogen bonding and has a calculated topological polar surface area of 0, consistent with low polarity but substantial polarizability and density arising from heavy halogen atoms.
Physicochemical behavior is typical of small haloforms: low aqueous polarity and modest lipophilicity (see logP), volatility sufficient to partition into air from water and soils, substantial density relative to water and limited chemical reactivity under neutral conditions. The compound is chemically stable toward neutral hydrolysis but can undergo oxidation and metabolic activation to reactive dihalocarbonyl species under strong oxidative or metabolic conditions. Its volatility and low aqueous sorption favor removal by volatilization from surface waters; anaerobic biodegradation can be significant whereas aerobic biodegradation is slow.
From an applied perspective, dibromochloromethane is encountered both as a synthetic intermediate and as an unintended disinfection by‑product of chlorination processes in water treatment. Occupational exposures occur in industrial settings where it is manufactured or used as an intermediate; environmental exposure pathways include inhalation of volatilized material and ingestion of contaminated water. Common commercial grades reported for this substance include: EP, JP, USP.
Basic Physical Properties
Density
Reported experimental values indicate a very high liquid density for a small organics: \(2.451\ \mathrm{g}\,\mathrm{cm}^{-3}\) at \(68\ ^\circ\mathrm{F}\) (reported), noted as denser than water and therefore likely to sink in aqueous matrices. A reported specific gravity value is \(2.38\) (dimensionless).
Melting Point
Two experimental values are reported: \(-8\ ^\circ\mathrm{F}\) (reported) and \(-20\ ^\circ\mathrm{C}\). If precise freezing behavior is required for processing or low-temperature storage, confirm the applicable value with batch-specific analytical data.
Boiling Point
Multiple experimental boiling point reports appear: \(246\)–\(248\ ^\circ\mathrm{F}\) at \(748\ \mathrm{mmHg}\) (reported), and \(121.3\)–\(121.8\ ^\circ\mathrm{C}\); alternate literature reports \(123\)–\(125\ ^\circ\mathrm{C}\). The compound is therefore a moderately volatile liquid at ambient temperature with a normal-boiling-range near \(121\)–\(125\ ^\circ\mathrm{C}\).
Vapor Pressure
Vapor-pressure data are reported as \(45.7\ \mathrm{mmHg}\) at \(63\ ^\circ\mathrm{F}\) and \(54.9\ \mathrm{mmHg}\) at \(75\ ^\circ\mathrm{F}\) (reported). An additional value is listed as \(5.54\ [\mathrm{mmHg}]\). These values indicate appreciable vapor pressure at ambient temperatures and support significant volatilization from aqueous or soil surfaces.
Flash Point
Conflicting reports appear in available experimental notes: an early summary states "No flash point." A later experimental note reports a flash point "greater than \(200\ ^\circ\mathrm{F}\)". For fire-hazard assessment treat the material as having low flammability under normal handling conditions but consult the product Safety Data Sheet for batch-specific flash-point determinations and emergency response.
Chemical Properties
Solubility and Phase Behavior
Reported solubility descriptors include: "less than 1 mg/mL at \(68\ ^\circ\mathrm{F}\)" (reported), and separately "In water, 2.70X10+3 mg/L at \(20\ ^\circ\mathrm{C}\)". The compound is described as "soluble in ethanol, ethyl ether, benzene, carbon tetrachloride, organic solvents, and acetone" and "Miscible in organic solvents." Several specific statements list solubility greater than \(10\%\) in acetone, benzene, ethyl ether and ethanol. Practically, dibromochloromethane is sparingly soluble to moderately soluble in water depending on measurement/report format but is readily miscible with most nonpolar and moderately polar organic solvents; it will partition strongly into organic phases and air.
Partitioning and volatility parameters: reported log Kow (log Kow) \(= 2.16\) and computed XLogP \(= 2.6\); Henry's Law and vapor-pressure numbers (see below) indicate a propensity to volatilize from aqueous systems.
Reactivity and Stability
The substance is chemically stable under neutral conditions but is incompatible with strong bases and strong oxidizing agents and with magnesium metal. Thermal decomposition and oxidative degradation produce hydrogen chloride, hydrogen bromide, carbon monoxide, carbon dioxide and reactive dihalocarbonyl (phosgene-analog) species; such degradation products are toxic and corrosive. Under basic conditions hydrolysis is negligible on short timescales, but a base-catalyzed second-order hydrolysis rate constant is reported as 3.1X10-4 L/mole-sec with estimated half-lives of centuries at neutral pH (e.g., 700 years at pH 7) and decades at elevated pH (e.g., 70 years at pH 8) (reported estimates). Metabolic activation in biological systems proceeds via mixed-function oxidases to reactive intermediates and can yield carbon monoxide and other products.
Thermodynamic Data
Standard Enthalpies and Heat Capacity
Available standard thermochemical data for the gas phase at \(25\ ^\circ\mathrm{C}\) include an enthalpy of formation of \(-5.0\) kcal/mole (gas), a Gibbs (free) energy of formation of \(-4.50\) kcal/mole (gas), and an entropy of \(78.31\) cal/deg·mole (gas). No experimental constant-pressure heat-capacity values are available in the current data context.
Molecular Parameters
Molecular Weight and Formula
- Molecular formula: \( \ce{CHBr2Cl} \)
- Molecular weight: \(208.28\) (reported)
- Exact mass: \(207.81130\) (reported)
- Monoisotopic mass: \(205.81335\) (reported)
- Heavy atom count: \(4\) These parameters reflect a single-carbon molecule bearing three heavy halogen substituents and one hydrogen.
LogP and Polarity
- Computed XLogP3-AA: \(2.6\) (reported)
- Experimental log Kow: \(2.16\) (reported)
- Topological polar surface area (TPSA): \(0\)
- Hydrogen-bond donor count: \(0\)
- Hydrogen-bond acceptor count: \(0\) The modest positive logP values indicate moderate lipophilicity consistent with phase-partitioning into organic phases and biological membranes, while the TPSA and hydrogen-bond metrics indicate minimal polar surface features.
Structural Features
Structurally the molecule is tetrahedral about carbon with no rotatable bonds beyond the symmetry-permitted orientations around C–X bonds; the reported rotatable-bond count is \(0\). The absence of H-bond functionality, combined with heavy halogens, results in low classical polarity but high polarizability, high molecular density, and significant refractive index (reported index of refraction \(= 1.5482\) at \(20\ ^\circ\mathrm{C}\)/D). Chemical complexity is reported as \(13.5\) (computed metric). The small size and lack of functional groups that undergo rapid hydrolysis explain the chemical persistence under aerobic conditions and the susceptibility to biotic anaerobic degradation pathways.
Identifiers and Synonyms
Registry Numbers and Codes
- CAS Registry Number: 124-48-1
- European Community (EC) Number: 204-704-0
- UNII: 3T4AJR1H24
- UN Number: 2810 (CHLORODIBROMOMETHANE)
- ChEBI: CHEBI:34627
- ChEMBL: CHEMBL157093
- DSSTox Substance ID: DTXSID1020300 (and DTXSID30188461)
- HMDB: HMDB0059903
- KEGG: C14692
Also associated identifiers and registry labels are reported in supplier and regulatory listings; confirm specific identifier usage for procurement and regulatory filings.
Synonyms and Structural Names
Common synonyms and alternative names reported for the substance include: chlorodibromomethane; dibromochloromethane; dibromo(chloro)methane; Monochlorodibromomethane; Chlorobromoform; CDBM; Dibromomonochloromethane; CHBr2Cl; CHClBr2; Methane, chlorodibromo-; Dibromochloromethane (stabilized with Ethanol). For analytical and procurement tasks, cross-check the synonym used by the supplier against the CAS number.
Also available molecular identifiers:
- SMILES: C(Cl)(Br)Br
- InChI: InChI=1S/CHBr2Cl/c2-1(3)4/h1H
- InChIKey: GATVIKZLVQHOMN-UHFFFAOYSA-N
(Above SMILES/InChI/InChIKey are provided as inline machine identifiers for structure matching and spectral database searches.)
Industrial and Commercial Applications
Representative Uses and Industry Sectors
Dibromochloromethane has been used as a chemical intermediate in the manufacture of other organic chemicals, including agents for fire extinguishing, aerosol propellants, refrigerants and certain pesticides. It is also encountered as a minor disinfection by‑product formed when chlorine reacts with natural organic matter during water treatment; consequently it is monitored in drinking-water quality programs. Environmental and occupational exposure routes therefore include industrial handling, use as an intermediate, and involuntary exposure through chlorinated water and swimming pools.
Role in Synthesis or Formulations
In synthesis it has been used as a reagent/intermediate, for example in the preparation of organomercury derivatives and in reactions that generate halocarbene intermediates (bromochlorocarbene). Its utility is principally as a halogenated building block or solvent-like reagent for nonpolar reaction media; it is not typically used where polar reactivity or hydrogen-bonding is required.
Reported commercial purities and formulations include analytical and stabilized solutions and common purity grades (e.g., 98% and 99% grade, and solution standards). For formulation development, consider the compound’s volatility, high density, and solvent miscibility when selecting co-solvents and stabilizers.
Safety and Handling Overview
Acute and Occupational Toxicity
Dibromochloromethane is an acute toxicant by multiple routes (oral, inhalation, dermal uptake) and produces central nervous system depression at high exposures. Target organs in animal studies include liver and kidney; hepatotoxicity and nephrotoxicity have been observed in repeated-dose studies. Reported acute median lethal doses include LD50 values such as rat oral LD50 \(= 370\ \mathrm{mg}\,\mathrm{kg}^{-1}\) (male) and higher values for female rats and mice (reported ranges available). The compound is metabolized via mixed-function oxidases to reactive intermediates capable of forming covalent adducts and yielding carbon monoxide as a metabolic product.
Hazard categorization reports include acute toxicity and specific-target-organ toxicity (narcotic effects), reproductive and genotoxicity flags in some notifications, and aquatic toxicity. Reported hazard statement codes include H302 (harmful if swallowed), H336 (may cause drowsiness or dizziness), H341 (suspected of causing genetic defects), H361 (suspected of damaging fertility or the unborn child), H373 (may cause damage to organs through prolonged or repeated exposure), and aquatic hazard statements (e.g., H401/H410/H411) depending on the specific classification set reported. The substance has shown limited evidence of carcinogenicity in some animal studies, while overall classification is "not classifiable as to carcinogenicity to humans (Group 3)" in available evaluations.
Occupational-control measures should emphasize minimizing inhalation and dermal exposure: engineering controls (local exhaust ventilation), appropriate respiratory protection when vapor concentrations exceed occupational limits, chemical‑resistant gloves (materials such as Viton or butyl rubber are commonly recommended), splash goggles or face shield, and protective clothing. In emergency rescue scenarios, use a self-contained breathing apparatus. Work practices should prevent skin contact and ingestion.
Storage and Handling Considerations
Store the material in a cool, well‑ventilated area, protected from light and heat. Maintain containers tightly closed under an inert atmosphere if stated by the supplier; avoid storage with strong oxidizers, strong bases, and reactive metals. Because thermal or oxidative decomposition can generate corrosive and toxic gases (HCl, HBr, CO, CO2 and reactive dihalocarbonyl species), control sources of ignition and heat and ensure appropriate gas‑phase and liquid‑phase fire suppression options are available.
For spills and releases, ventilate the area and use absorbent media; collect for recovery or disposal and avoid discharge to drains. Do not touch spilled material without appropriate PPE. For firefighting, use dry chemical, CO2 or other suitable extinguishing agents; avoid direct contact with decomposition products. For waste handling and disposal consult local regulation and the product-specific safety documentation.
For detailed hazard, transport and regulatory information, users should refer to the product-specific Safety Data Sheet (SDS) and local legislation.
