Ammonium fluoride - UPSSS grade,Single metal impurity ≤ 0.01ppb, 40wt.% in H2O , CAS No.12125-01-8

CAS: 12125-01-8 Cat. No.: A1524117 Formula: H₄FN Molecular Weight: 37.04 EC Number: 235-185-9 PubChem CID: 25516

GRADE & PURITY UPSSS grade, Single metal impurity ≤ 0.01ppb, 40wt.% in H2O

Storage

Room temperature

Shipped In

Normal

Specifications

Specifications & Purity

UPSSS grade,Single metal impurity ≤ 0.01ppb, 40wt.% in H2O

Storage

Room temperature

Shipped In

Normal

Grade

UPSSS grade

Names and Identifiers

Isomeric SMILES

[NH4+].[F-]

WGK Germany

1

RTECS

BQ6300000

PubChem CID

25516

UN Number

2505

Packing Group

III

Molecular Weight

37.04

Chemical and Physical Properties

• Solubility: Soluble in cold water, slightly soluble in alcohol, insoluble in ammonia

Application Protocols

No antibody- or assay-specific protocols are associated with this inorganic salt. For general laboratory use:

• Solution preparation: dissolve the required mass of ammonium fluoride in deionized water or methanol/water mixtures using plastic (HDPE/PTFE) vessels. Stir until fully dissolved. Avoid glass containers to prevent etching and silicate contamination.
• Materials etching (BOE): follow institutional SOPs for HF-containing baths; prepare compositions by volume or mass per validated procedures; use secondary containment and dedicated plasticware.
• Desilylation screens: prepare stock NH4F solutions in MeOH (e.g., 1–5 M), dispense into reaction vials, add substrate, and monitor by TLC/LC–MS. Quench and neutralize fluoride before workup.

All uses are for research/laboratory purposes only. Refer to method-specific literature or internal SOPs for detailed parameters.

Biological Roles

Ammonium fluoride is not a biomolecule and has no native role in physiology. The following points are general/literature context for laboratory biochemists; they are not product specifications and do not imply suitability for clinical/diagnostic use.

• Fluoride ion effects: F− can inhibit metalloenzymes and phosphatases by forming metal–fluoride complexes that mimic phosphate in transition states. These interactions are widely used in mechanistic enzymology to trap GDP•AlF4− or BeF3− analogs (prepared in situ with separate reagents) to study GTPase and ATPase catalytic cycles.
• Ammonium ion effects: NH4+ can participate in nitrogen assimilation pathways as an inorganic nitrogen source in some microorganisms. In vitro, elevated ammonium levels can alter enzyme kinetics or protein conformation via ionic strength and pH effects.
• Cytotoxicity: fluoride salts can be cytotoxic at modest millimolar concentrations, compromising membrane integrity and enzyme function; effects are highly cell-type and medium dependent (literature).

Practical implications:

• If using NH4F in biochemical experiments, carefully control concentration, pH, and counterions; account for the acidity of fluoride solutions and potential HF formation.
• Avoid glass containers for stock solutions to prevent fluoride loss via etching and silicate contamination. Use plastic consumables.

Note: This product is provided “For research use only,” not for diagnostic or therapeutic applications.

Buffer Applications

Ammonium fluoride is not a standard biological buffering agent. Its aqueous solutions are acidic due to equilibria involving HF and NH4+, and they lack a well-defined, narrow buffering range suitable for routine biochemical assays.

• Not typically applicable: For pH-controlled biological work, use established buffers (e.g., phosphate, Tris, HEPES, MOPS) designed for specific pH windows.
• Materials science context: Ammonium fluoride is deliberately combined with HF to make “buffered oxide etch” (BOE) for silicon dioxide etching; this is an industrial/materials buffer system, not a biological one.

If an ammonium-based buffer is desired for analytical chemistry, ammonium acetate or ammonium formate are more appropriate volatile buffers for LC–MS workflows.

Green Alternatives

Perspective on greener or safer choices depends on the intended task.

• Etching SiO2 (BOE-type processes):

  • NH4F + HF (BOE) vs anhydrous HF: BOE offers improved handling and etch-rate control but still involves HF hazards. Engineering controls (closed baths, fume hoods, plasticware) and waste neutralization to CaF2 are key to risk mitigation.
  • Alternative chemistries: dry plasma (CF4/CxFy/H2/Ar) or vapor-phase HF processes can reduce aqueous fluoride waste but introduce greenhouse gases or specialized equipment; trade-off between GHG impact and aqueous HF handling.

• Fluoride source in organic synthesis:

  • NH4F in MeOH/H2O can be a simpler, salt-based alternative to tetrabutylammonium fluoride (TBAF), avoiding quaternary ammonium waste and THF stabilizers. However, water content and glass etching remain concerns.
  • KF or CsF in polar aprotic solvents (sometimes with 18-crown-6) avoid HF liberation in protic media and reduce corrosivity toward glassware, but crown ethers are not green and CsF has higher resource intensity.

Comparison highlights (literature):

• NH4F(aq): inexpensive, effective, but HF-related corrosivity/toxicity; plastic equipment required.
• KF/CsF: lower volatility/toxicity profile than HF systems; may require phase-transfer agents and higher temperatures.
• Solid-supported fluoride (resins): facilitate separation and potential recyclability; capacity and cost can be limiting.

Green practice tips:

• Minimize fluoride excess; capture/neutralize effluents to insoluble CaF2.
• Prefer closed systems and inline monitoring to reduce exposures and emissions.

Pharmaceutical Uses

Ammonium fluoride is not commonly used as a pharmaceutical excipient. The following notes are general context and do not constitute medical or clinical claims.

• Formulation relevance: Fluoride salts are generally avoided in conventional dosage forms due to toxicity and corrosivity concerns. Ammonium fluoride does not have a recognized pharmacopeial excipient monograph comparable to common ammonium salts like ammonium acetate or ammonium bicarbonate.
• Manufacturing/analytical context: In specialized materials handling (e.g., etching/cleaning of silica-based components), ammonium fluoride solutions may appear in device or equipment preparation workflows, but such uses are strictly industrial and tightly controlled due to HF-related hazards.

Conclusion: For pharmaceutical development, consider alternative ammonium salts when volatile buffers or leavening agents are needed (e.g., ammonium acetate/formate/bicarbonate). Any use of fluoride salts must undergo rigorous risk assessment and compatibility studies.

Physical Properties

Item-specific specifications for the following are Not specified for this item; refer to CoA/Spec Sheet.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Density, refractive index, trace-metal content, water/peroxide content: Not specified for this item; refer to CoA/Spec Sheet.

General/literature properties (for context only; not vendor specifications):

• Physical form: typically a white, odorless, hygroscopic crystalline solid (literature).
• Thermal behavior: ammonium fluoride can melt and/or decompose on heating; at elevated temperatures it can release HF and NH3 (literature). Avoid heating in glass due to potential etching by released HF.
• Solubility: highly soluble in water; solubility increases with temperature (literature). Sparingly soluble to moderately soluble in lower alcohols; essentially insoluble in nonpolar solvents (literature).
• Aqueous solution character: aqueous solutions are mildly acidic due to HF formation from F− + H2O ⇌ HF + OH− and the conjugate acid-base equilibria with NH4+ (literature). Buffering with HF (buffered oxide etch) is used in materials processing, not in biological buffering.
• Hygroscopicity: absorbs moisture and may cake on exposure to humid air (literature). Store tightly closed.

Notes for practitioners:

• Preparing solutions in plastic (HDPE or PTFE) vessels is recommended; fluoride-containing solutions can attack silicate glass over time (literature).
• Drying: avoid high-temperature drying; if drying is required, use mild vacuum at ambient or slightly elevated temperature with care (literature guidance).

Quality and Grades

• Supplied grade: UPSSS grade (as listed in Product Data).
• What this means: UPSSS is a supplier/brand-specific grade designation. Exact acceptance criteria (e.g., assay, metals profile, moisture limits, particle size) are Not specified for this item; refer to CoA/Spec Sheet for definitive specifications and analytical methods.

Considerations for selecting this item/grade:

• Fluoride chemistry is sensitive to trace metal impurities and silica contamination. If you intend to use ammonium fluoride in microfabrication (e.g., buffered oxide etch) or high-purity materials synthesis, consult the CoA for trace-metal analysis and particle contamination limits.
• For synthetic applications (e.g., desilylation), water content and residual ammonium salts can influence reaction rates and selectivity. Verify Karl Fischer moisture or LOI data if your process is water sensitive; Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/additives: none indicated. If any anti-caking agents or stabilizers are present, they would be listed on the CoA; Not specified for this item; refer to CoA/Spec Sheet.

Quality control documentation:

• Request batch-specific CoA including assay (wt%), ICP-MS metals, anions/cations by IC, pH of standard solution, and particle analysis when relevant to your application.

Reaction and Applications

Materials science and synthesis roles (literature; expand from catalog category “Materials Science”):

• Silicon dioxide and oxide-ceramic processing: aqueous ammonium fluoride forms buffered oxide etch (BOE) when combined with HF, widely used for isotropic etching of SiO2, PSG/BSG, and cleaning native oxides from silicon and glass. Ammonium cation moderates free HF activity, improving etch rate control compared with anhydrous HF alone.
• Surface preparation: removes metal oxides and passivation layers prior to deposition (CVD/ALD), improving adhesion and electrical properties; typically employed as controlled, dilute solutions in plastic equipment.
• Fluoride source in synthesis: provides F− to cleave Si–O and Si–C bonds in organosilicon chemistry. Examples include desilylation of silyl ethers and deprotection of silyl-enol ethers under protic conditions (e.g., NH4F/MeOH), serving as a milder alternative to TBAF.
• Zeolite/sol–gel roles: used as a mineralizer/fluoride source to direct framework formation in certain silica-rich materials, impacting pore topology and crystallinity.
• Inorganic transformations: precipitation of metal fluorides (e.g., CaF2) from solutions during waste treatment or material synthesis, leveraging the low solubility of many MFx phases.

Practical tips (literature):

• Use plastic (HDPE/PTFE) for solution preparation and storage; avoid prolonged contact with glass.
• Control pH and NH4F:HF ratio in etching baths to tune etch rates/selectivity; maintain temperature consistency.
• For organic desilylations, protic solvents (MeOH, EtOH) and ambient to mild heating often suffice; monitor closely to avoid over-deprotection.

Reaction Conditions

General literature guidance (not product specifications; optimize for each substrate/process):

• Desilylation of silyl ethers:

  • Reagents/solvent: NH4F (2–10 equiv) in MeOH or MeOH/H2O (typically 0.1–1 M with respect to substrate).
  • Temperature/time: ambient to 50 °C; minutes to a few hours depending on steric bulk (TMS > TBDMS > TBDPS) and electronic factors.
  • Workup: dilute with water, extract with suitable organic solvent; or neutralize F− as CaF2 using aqueous CaCl2 before disposal.

• Buffered oxide etch (BOE) for SiO2 (materials processing):

  • Composition: aqueous NH4F combined with HF to achieve defined ratios (e.g., “7:1” or similar formulations in the literature). Selection controls free HF activity and etch rate/selectivity for different oxides.
  • Equipment: plastic tanks (HDPE/PP/PTFE), Teflon wafer holders, temperature control (often 20–25 °C). Continuous monitoring of bath age and etch rate is standard practice.
  • Safety: HF protocols, PPE, and calcium-based neutralization are mandatory; follow institutional SOPs.

• Precipitation of metal fluorides:

  • Mix metal salt solution with stoichiometric/excess NH4F under stirring (aqueous); adjust pH as required; isolate precipitated MFx by filtration and wash thoroughly.

Notes:

• Aprotic nucleophilic fluorination typically prefers CsF/KF or TBAF; NH4F is more effective in protic or mixed media.
• Always verify compatibility of substrates with acidic/protic conditions introduced by NH4F solutions.

Safety and Handling

Hazard classification (GHS) and H-statements: Not specified for this item; consult the product SDS for authoritative classification.

General safety considerations (literature/prudent practice):

• Corrosivity/toxicity: fluoride salts can be harmful if swallowed or inhaled and can cause severe skin and eye irritation or burns, especially in the presence of moisture, due to HF generation. Treat with the same respect as other fluoride sources.
• Special risk: aqueous solutions and damp solid can liberate HF, which penetrates tissue and binds calcium and magnesium. Ensure calcium gluconate gel is available in HF-handling laboratories. For exposure management, follow institutional protocols and SDS guidance.
• PPE: wear chemical-resistant gloves (e.g., nitrile; consider double-gloving for wet work), lab coat, eye protection (chemical splash goggles), and use a face shield for bulk solution handling. Use in a fume hood to avoid inhalation of dust or aerosols.
• Incompatibilities: acids (increase HF liberation), strong bases (vigorous neutralization and ammonia release), glass/silicates in solution (etching), and reactive metals in the presence of moisture. Avoid contact with oxidizers until compatibility is verified.
• First aid (overview; defer to SDS):
  • Skin/eye contact: immediate copious water rinse; remove contaminated clothing; seek medical attention. For suspected HF exposure, apply calcium gluconate gel per protocol.
  • Inhalation: move to fresh air; medical evaluation is essential.
  • Ingestion: do not induce vomiting; seek urgent medical care.
• Spill response: avoid dust; carefully collect solid or neutralize solutions with appropriate calcium salts to precipitate CaF2; dispose per regulations.

Solvent Selection

Ammonium fluoride is an inorganic salt; solvent choice is primarily dictated by intended application and required ion availability.

• Polarity/miscibility (literature):
  • Water: highly soluble; complete dissociation to NH4+ and F− provides maximum fluoride activity.
  • Alcohols (MeOH, EtOH): limited to moderate solubility; may suffice for certain desilylation protocols where protic, less aqueous media are preferred.
  • Polar aprotic solvents (MeCN, DMF, DMSO): solubility is variable and generally lower than in water; using phase-transfer strategies or alternative fluoride sources (e.g., TBAF) is often more effective for strictly aprotic conditions.
  • Nonpolar solvents (hexanes, toluene): essentially insoluble; not recommended.

Selection guidance:

• For materials etching (BOE), aqueous NH4F is combined with HF; prepare and store in plastic apparatus.
• For hydrolysis/desilylation in organic synthesis, MeOH or MeOH/H2O systems balance solubility with substrate compatibility; consider temperature to increase dissolution but avoid glassware for prolonged contact.
• For water-sensitive substrates, alternative fluoride sources (TBAF in THF, CsF in DMF) may be preferable despite their own hazards.

Quick comparison (literature trends):

• NH4F(aq): high fluoride activity, acidic medium, glass-etching risk.
• NH4F in MeOH: milder, useful for certain silyl ether cleavages.
• CsF/KF (crown): basic, good in polar aprotics; stronger nucleophilicity of F−.
• TBAF: highly soluble in organics; strong, but may contain water and decompose on storage.

Storage and Reconstitution

• Storage temperature (from Product Data): Room temperature.
• Shipping (from Product Data): Shipped under normal conditions.
• Container/materials: store in tightly closed containers made of plastic (HDPE, PP, or PTFE). Avoid glass for solutions due to etching by fluoride; the solid is also best kept in plastic to minimize contact with silicates.
• Atmosphere/humidity: protect from moisture; ammonium fluoride is hygroscopic and may cake upon exposure to humid air. Store in a desiccator or with desiccant if ambient humidity is high.
• Segregation: keep away from acids (to limit HF liberation), strong bases, and oxidizers until compatibility is confirmed. Avoid storing near materials sensitive to corrosion by fluoride-containing vapors.
• Reconstitution/solution preparation: prepare solutions using deionized water or suitable alcohol/water mixtures in plasticware. Add solid slowly with stirring; cooling may be beneficial for concentrated solutions. Label solutions clearly as fluoride-containing and date them; replace periodically as needed.
• Freeze–thaw: not typically applicable to inorganic salts. If preparing concentrated stock solutions, room-temperature storage in plastic is typical; refrigerate if required by your SOPs, but avoid freezing containers that may become brittle.
• Stability: Item-specific stability data are Not specified for this item; refer to CoA/Spec Sheet. As a general precaution, avoid elevated temperatures and prolonged storage of solutions to limit container attack and compositional drift.

Research Use Note: For research use only.

Structure and Identity

Ammonium fluoride is an inorganic ionic salt composed of the ammonium cation and fluoride anion.

• Item-specific identifiers (from Product Data):

  • SKU: A1524117
  • Product name: Ammonium fluoride
  • CAS: 12125-01-8
  • Grade: UPSSS grade
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.

• Computed/literature identity data (general information):

  • Molecular formula: NH4F
  • Molecular weight: ~37.04 g/mol (literature)
  • Preferred SMILES (ionic): [NH4+].[F-] (literature)
  • Structure description: a discrete tetrahedral ammonium cation (N center with four equivalent N–H bonds) electrostatically paired with a spherical fluoride anion. In the solid state, ions arrange in a hydrogen-bonded lattice; in water, complete dissociation yields NH4+ and F−.
  • Functional groups/structural features: inorganic salt; hydrogen-bond donor (NH4+); strong hydrogen-bond acceptor (F−); no stereocenters; no covalent heterocycles.

• Category context: Listed under Materials Science, consistent with its common use in microfabrication/etching chemistry and as a fluoride source in inorganic/organic synthesis.

Synthetic Utility

Ammonium fluoride serves as a convenient inorganic source of fluoride ion under protic conditions and plays distinctive roles in both materials processing and organic/inorganic synthesis (literature context).

• Desilylation and silicon chemistry:
  • Cleavage of silyl ethers (e.g., TMS-, TBDMS-, TBDPS-protected alcohols) and silyl enol ethers using NH4F in MeOH or MeOH/H2O, often at ambient temperature. Compared to TBAF, the medium is more protic/acidic, which can offer complementary selectivity and minimize base-sensitive side reactions.
  • Hydrolysis of Si–O–Si linkages in silicones/siloxanes; controlled depolymerization or surface activation.
• Formation of metal fluorides:
  • Precipitation of sparingly soluble MFx salts for purification, separation, or as precursors to advanced materials (e.g., CaF2, MgF2 thin films by subsequent processing).
• Mineralizer in sol–gel/zeolite synthesis: Fluoride assists in building highly ordered silica-rich frameworks, influencing morphology and defect densities.
• Halogen exchange and activation: While CsF/KF are typical for nucleophilic fluorination in aprotic media, NH4F can assist in certain hydrofluorinolysis or acidic fluorination steps where protic conditions are beneficial.

Practical guidance:

• Choose solvent to balance solubility and substrate stability (water/MeOH commonly used).
• Avoid prolonged contact with glass; use plastic or PTFE-lined equipment.
• Monitor for ammonolysis or hydrolysis side reactions due to NH4+/protic medium.

Target Specificity

Not applicable. This product is an inorganic salt, not a biological affinity reagent or antibody. No antigen/epitope specificity, clone, isotype, or species reactivity apply.