1,2-Dimethoxyethane (110-71-4) Physical and Chemical Properties

Chemical Profile

1,2-Dimethoxyethane

Low‑molecular-weight glycol ether used as a polar, aprotic solvent in industrial synthesis and analytical workflows.

CAS Number	110-71-4
Family	Glycol ethers (dialkyl ether)
Typical Form	Colorless liquid
Common Grades	EP, JP, USP

Commonly employed in organic synthesis, extraction and as a solvent for electrolytes and reagents where moderate polarity and water miscibility are required. Procurement and quality control typically specify grade and water/impurity limits (for example anhydrous or reagent grades) to support formulation, R&D and manufacturing processes.

1,2-Dimethoxyethane is a small aliphatic diether (glyme family) with the empirical formula C4H10O2 and molecular weight 90.12. Structurally it is the 1,2-dimethyl ether of ethylene glycol (CH3OCH2CH2OCH3); the molecule consists of an ethylene backbone bearing two terminal methoxy groups. Electronically it is a neutral, aprotic ether with two lone‑pair‑bearing oxygen atoms (hydrogen bond acceptor count = 2, donor count = 0) and a modest topological polar surface area (TPSA = 18.5 Å^2). The solvent shows low intrinsic lipophilicity (reported XLogP ≈ −0.2, Log Kow ≈ −0.21) and behaves as a polar aprotic medium that solvates cations and polar reagents while remaining miscible with many organic solvents.

Acid–base behavior is negligible (no acidic protons), and the substance does not form strong hydrogen bonds as a donor; solvation of ionic species arises from coordination to ether oxygens. It is readily volatilized (measured vapor pressure ~48 mmHg at \(20\,^\circ\mathrm{C}\)) and produces vapors heavier than air (vapor density ≈ 3.1 relative to air). The ether functionality is relatively resistant to hydrolysis under neutral conditions but is susceptible to oxidation and peroxide formation on prolonged exposure to air and especially upon concentration or distillation; contact with strong oxidizers should be avoided. The compound is highly flammable and exhibits narcotic effects at elevated vapor concentrations; repeated exposures are associated with reproductive toxicity in animal studies.

Common commercial grades reported for this substance include: EP, JP, USP.

Basic Physical Properties

Density

Reported values: 0.868 at \(68\,^\circ\mathrm{F}\) (USCG, 1999); 0.86285 @ \(20\,^\circ\mathrm{C}/4\,^\circ\mathrm{C}\); relative density (water = 1): 0.86.
Interpretation: the liquid is less dense than water and will float on aqueous layers. Reported densities are consistent with small, oxygen‑containing ethers and are relevant for spill containment and phase‑separation behavior in formulations.

Melting Point

Reported values: −72 \(^{\circ}\mathrm{F}\) (NTP, 1992); −58 \(^{\circ}\mathrm{C}\) (also reported −71 \(^{\circ}\mathrm{C}\)).
Interpretation: very low melting point (well below ambient) — the compound exists as a liquid under standard storage and handling temperatures.

Boiling Point

Reported values: 185 \(^{\circ}\mathrm{F}\) at \(760\,\mathrm{mmHg}\) (NTP, 1992); 82–83 \(^{\circ}\mathrm{C}\) @ \(760\,\mathrm{mmHg}\).
Interpretation: moderate boiling point typical of low‑molecular‑weight glyme solvents; compatible with common distillation and solvent‑recovery operations but care is required because of flammability and peroxide risk on concentration.

Vapor Pressure

Reported values: 40 mmHg at \(51.3\,^\circ\mathrm{F}\); 60 mmHg at \(67.5\,^\circ\mathrm{F}\) (NTP, 1992); 48.0 mmHg (reported); 48 mmHg @ \(20\,^\circ\mathrm{C}\); vapor pressure \(= 6.4\,\mathrm{kPa}\) at \(20\,^\circ\mathrm{C}\).
Interpretation: substantial vapor pressure at ambient temperatures — the solvent produces significant vapor concentrations and requires ventilation and airborne exposure control in industrial use.

Flash Point

Reported values: 32 \(^{\circ}\mathrm{F}\) (NTP, 1992); −2 \(^{\circ}\mathrm{C}\) (closed cup: 29 \(^{\circ}\mathrm{F}\) / −2 \(^{\circ}\mathrm{C}\)).
Interpretation: low flash point; the material is classified as highly flammable and requires ignition‑source control, grounding/bonding during transfer, and appropriate flammable storage.

Chemical Properties

Solubility and Phase Behavior

Reported solubility: miscible with water and alcohols; solubility in water reported as ≥100 mg/mL at \(72\,^\circ\mathrm{F}\) and as 1.00×10^6 mg·L^-1 at \(25\,^\circ\mathrm{C}\); soluble in chloroform, diethyl ether, acetone and benzene.
Molecular descriptors: hydrogen bond acceptor count = 2; donor count = 0; TPSA = 18.5; Log Kow ≈ −0.21.
Interpretation: despite a net non‑ionic character, the two ether oxygens impart polarity sufficient for full miscibility with water and polar protic solvents. The solvent is well suited to dissolve both polar and some nonpolar organic substrates; miscibility with water influences extraction, phase‑separation, and formulation strategies in process chemistry. Vapor is heavier than air (vapor density ≈ 3.1), so vapors may accumulate in low‑lying areas.

Reactivity and Stability

Key reactivity notes: classified among ethers and flagged as a peroxide‑forming compound (class B*: peroxides form on concentration/distillation). Samples aged for years can accumulate peroxides; incidents including detonation during distillation of peroxidized samples have been reported. The compound is highly flammable and reacts vigorously with strong oxidizers.
Practical implications: avoid prolonged storage of bulk solvent in open containers; use peroxide inhibitors where specified, test for peroxide content before concentration or distillation, and discard or treat peroxide‑containing material per established safety procedures. Keep away from strong oxidizing agents and reactive metals (e.g., alkali metals in inappropriate solvent conditions) unless procedures account for reactivity.

Thermodynamic Data

Standard Enthalpies and Heat Capacity

Reported heats: heat of combustion values given as −12,020 BTU·lb^-1 = −6680 CAL·g^-1 = −279.7X10+5 J·kg^-1 (reported formatting retained); heat of vaporization reported as 134 BTU·lb^-1 = 74.6 CAL·g^-1 = 3.12X10+5 J (reported). Heat of solution (estimated) ≈ −9 BTU·lb^-1 = −5 CAL·g^-1 = −0.2X10+5 J·kg^-1 (reported). Ratio of specific heats of vapor (gas): 1.071. Surface tension: 0.02461 N·m^-1 at \(20\,^\circ\mathrm{C}\). Refractive index: 1.3813 @ \(20\,^\circ\mathrm{C}\)/D; 1.3739 @ \(24\,^\circ\mathrm{C}\)/D. Reported pH (aqueous) ≈ 8.2.
Interpretation: the thermochemical values reflect typical energy content for combustible organic ethers and are relevant for fire hazard assessment and thermal calculations in process safety analysis. Surface tension and refractive index are useful for liquid handling, quality control, and optical measurements.

Molecular Parameters

Molecular Weight and Formula

Molecular formula: C4H10O2.
Molecular weight: 90.12.
Exact/monoisotopic mass: 90.068079557.

LogP and Polarity

Reported partitioning metrics: XLogP = −0.2 (computed); Log Kow ≈ −0.21 (experimental estimates).
Interpretation: negative LogP indicates preferential partitioning into aqueous phase versus nonpolar phases; this correlates with the reported miscibility with water and low bioconcentration potential.

Structural Features

SMILES: COCCOC
InChI: InChI=1S/C4H10O2/c1-5-3-4-6-2/h3-4H2,1-2H3
InChIKey: XTHFKEDIFFGKHM-UHFFFAOYSA-N
Counts and descriptors: heavy atom count = 6; rotatable bond count = 3; complexity ≈ 17–17.5; formal charge = 0; hydrogen bond acceptor count = 2; donor count = 0.
Interpretation: compact, flexible ether chain with three rotatable bonds and two lone‑pair‑bearing oxygens; the molecular architecture supports coordination to cations and solvation of polar reagents while maintaining low steric hindrance.

Identifiers and Synonyms

Registry Numbers and Codes

CAS number: 110-71-4
EC number: 203-794-9
UN number (shipping): 2252
UN/NA/DOT shipping designation present as: UN 2252; 1,2‑Dimethoxyethane
Other identifiers appearing in source material: UNII = GXS24JF5IW; ChEBI = CHEBI:42263; DrugBank = DB01749; various internal registry codes.
Note: these identifiers are widely used for procurement, regulatory filing and transport documentation.

Synonyms and Structural Names

Common synonyms appearing in source information include: 1,2-dimethoxyethane; dimethoxyethane; ethylene glycol dimethyl ether; glyme; monoglyme; ethylene dimethyl ether; dimethyl cellosolve; DME; glycol dimethyl ether; monoethylene glycol dimethyl ether.
IUPAC name: 1,2-dimethoxyethane.

Industrial and Commercial Applications

Representative Uses and Industry Sectors

Representative uses: specialty solvent and reagent in chemical synthesis, processing aid, functional fluid in closed systems, solvent in battery manufacturing and industrial coatings, and as a component in formulations where polar aprotic properties are required. Listed uses include solvent to facilitate formation of alkali metal–hydrocarbon adducts and as a medium in Reformatsky‑type reactions.
Industry sectors: fine chemical and pharmaceutical manufacturing, battery and coatings industries, and specialty solvent supply chains. The compound has historical and ongoing use as a process solvent and formulation ingredient owing to its polarity and miscibility profile.

Role in Synthesis or Formulations

Functional role: polar aprotic solvent that solvates cations and dissolves many organic substrates; useful for reactions requiring coordination to oxygen donors without proton donation (e.g., organometallic chemistry, alkali metal dispersions). Its miscibility with polar solvents and ability to stabilize ionic intermediates make it a reagent‑grade solvent for selected synthetic procedures.
Practical considerations: selection for synthesis balances solvent performance against toxicity and peroxide‑formation hazards; use in battery electrolytes leverages coordinating ability but requires rigorous control of water and impurities.

Safety and Handling Overview

Acute and Occupational Toxicity

Acute toxicity data: LCLo (rat, inhalation) = 17,096 ppm/6 h (reported). Reported human and animal effects include dizziness, narcosis, respiratory irritation at elevated vapor exposures, nausea and central nervous system depression on ingestion, and severe eye/skin irritation on contact in some reports. Animal reproductive and developmental toxicity has been observed (maternal/fetal effects and increased fetal mortality in rodent studies at experimental doses). Reported TLV: 0.5 ppm (threshold limit value).
Hazard classifications and statements (reported): H225 — Highly flammable liquid and vapor; H332/H336 — harmful if inhaled / may cause drowsiness or dizziness; H360/H360FD — may damage fertility; may damage the unborn child; H315 — causes skin irritation (reported in some notifications). Users should treat the material as a flammable solvent with potential neurotoxic and reproductive hazards under repeated or high exposures.

Storage and Handling Considerations

Storage: store in a cool, well‑ventilated, fireproof area, separated from strong oxidizing agents; containers should be tightly closed and grounded/bonded during transfer. Avoid storage in containers or systems where peroxide concentration could increase (do not distil aged samples without peroxide testing).
Handling: eliminate ignition sources; use explosion‑proof electrical equipment and instrumentation; ensure local exhaust ventilation or closed‑system handling to limit vapor concentrations; use appropriate bonding and grounding for transfers of bulk volumes. For spill response, isolate area, eliminate ignition sources, use vapor suppression if available, absorb with inert material and collect with non‑sparking tools.
Personal protective equipment: chemical splash goggles, chemical‑resistant gloves (vinyl has been cited as acceptable in some guidance), and protective clothing; for potential high‑concentration exposures, use appropriate respiratory protection (e.g., supplied‑air or positive‑pressure respirator) and follow industrial hygiene monitoring.
Special hazards: peroxide formation on prolonged storage and during concentration/distillation — test for peroxides before distillation or evaporation and manage per established peroxide‑control procedures. Vapors are heavier than air and may collect in low areas; use caution for vapor migration and flashback. Lower explosive limit and upper explosive limit reported as 1.6% and 10.4% (v/v) respectively. Autoignition temperature reported as 202 \(^{\circ}\mathrm{C}\) (395 \(^{\circ}\mathrm{F}\)).
Emergency advice: in case of fire use dry chemical, carbon dioxide, alcohol‑resistant foam or water spray as appropriate; cool exposed containers with water. First aid: remove to fresh air for inhalation exposure; flush eyes and skin with water for contact; do not induce vomiting for ingestion — seek immediate medical attention. For detailed hazard, transport and regulatory information, users should refer to the product‑specific Safety Data Sheet (SDS) and local legislation.