Ammonium octamolybdate - ≥99.9% metals basis , CAS No.12411-64-2

CAS: 12411-64-2 Cat. No.: A302284 Formula: H₁₆Mo₈N₄O₂₆ Molecular Weight: 1255.66 EC Number: 235-650-6

GRADE & PURITY ≥99.9% metals basis

Storage

Room temperature

Shipped In

Normal

Overview

The product is a white powder, soluble in ammonia and alkaline solutions. Dissolve 0.4g in 100 milliliters of water at 25 ℃. The density is 3.18g/cm2. Industrial use. Plastic flame retardant, used for nylon and rubber.

Specifications

Specifications & Purity

≥99.9% metals basis

Storage

Room temperature

Shipped In

Normal

Purity

≥99.9% metals basis

Names and Identifiers

Molecular Weight

1255.66

Chemical and Physical Properties

• Melt Point(°C): >360° C

Application Protocols

No manufacturer-validated biological assay protocols are provided for this item. The following guidance points are general, literature-driven starting points and should be adapted to your system.

• Preparing a stock solution (generic):
  • Dissolve the required mass in deionized water to a defined Mo concentration (e.g., 0.05–0.5 M as total Mo). Adjust pH with dilute NH4OH or acid depending on the desired speciation.
  • Filter (0.2 µm) if particulate-free solutions are required for coatings or kinetic studies.
• Catalyst setup (generic):
  • For peroxo oxidations, mix the aqueous AOM solution with H2O2 under cooling; then add to a stirred solution of substrate in a miscible organic solvent (e.g., MeCN, EtOH) or operate under biphasic conditions with vigorous mixing.
• Coating workflow (generic):
  • Clean substrate, apply AOM solution by spin/dip/spray, dry below 120°C to remove water, then calcine in air to form MoO3.
• Analytical assay component (generic):
  • Prepare fresh acidic reagent containing molybdate when forming heteropoly complexes for phosphate/silicate colorimetry; follow your validated method for reagent ratios and reduction steps.

Item-specific, validated protocols (e.g., WB, IHC, IF, FC) are not applicable for this inorganic salt. Always consult primary literature or internal SOPs for tuned conditions.

Biological Roles

This product is intended for research use only. Any discussion below reflects general biochemical knowledge about molybdate species and polyoxometalates; it is not a medical or clinical claim.

• Molybdenum in biology (literature/generic):
  • Molybdenum is an essential trace element incorporated as the molybdenum cofactor (Moco) in enzymes such as xanthine oxidoreductase, aldehyde oxidase, and sulfite oxidase.
  • In aqueous media, molybdenum(VI) is present as molybdate (MoO4^2−) at physiological pH; at lower pH it can form polymolybdates (e.g., heptamolybdate, octamolybdate). Transport into cells typically involves sulfate/molybdate transporters.
• Laboratory relevance (literature):
  • Molybdate ions can inhibit certain phosphatases and interact with phosphate-dependent pathways, used experimentally to probe enzyme mechanisms.
  • Polyoxometalates (POMs) display diverse interactions with biomolecules via electrostatics and hydrogen bonding; they are used as crystallographic additives and in protein surface engineering studies.
• Practical notes for life-science workflows:
  • Buffer composition and ionic strength dramatically affect molybdate speciation; maintain consistent pH/ionic background to ensure reproducibility.
  • Avoid reducing environments if Mo(VI) integrity is required; reductants can convert to lower-valent Mo species.

No item-specific biological specifications are provided here; consult the literature for experimental design and the SDS for toxicological information.

Buffer Applications

Ammonium octamolybdate itself is not a buffering agent. However, it is frequently employed in buffered aqueous systems where pH governs molybdate speciation and performance.

• Use within buffers (literature/generic):
  • Common matrices: Acetate (pH 4–5.5), citrate (pH 3–6), phosphate (pH 6–7.5), and ammonium-based buffers (to keep the counterion consistent) are used depending on the desired polyoxomolybdate distribution.
  • Colorimetric assays: In phosphate determination (molybdenum blue), acidic media (e.g., sulfuric acid) and appropriate reductants are used to form heteropolyacids and their reduced blue complexes.
• Practical guidance:
  • If maintaining the [Mo8O26]4− species is crucial, operate near mildly acidic to neutral pH and moderate ionic strength; avoid strong acids that favor heteropolyacid formation unless that is the goal.
  • Match counterions to avoid precipitation (e.g., high concentrations of multivalent cations can cause insoluble molybdates).

Item-specific buffer recommendations and concentrations are not specified; design conditions empirically for your assay or synthesis.

Green Alternatives

Evaluating greener choices focuses on counterion selection, solvent systems, and process integration rather than changing the Mo(VI) center.

• Counterion considerations (literature/generic):
  • Ammonium vs. sodium/potassium molybdate: Ammonium salts avoid introduction of persistent alkali metals, facilitating closed-loop recovery and cleaner calcination to MoO3 with volatile byproducts (NH3/H2O). This can simplify waste streams and reduce metal contamination.
• Solvent footprint:
  • Favor water or water–bioalcohol (EtOH) mixtures for catalytic oxidations with H2O2 as the terminal oxidant. These combinations minimize VOCs and hazardous oxidants compared with peracids or chlorinated systems.
• Process intensification options:
  • Use of aqueous biphasic systems or micellar catalysis to keep the molybdate phase aqueous and recyclable while processing hydrophobic substrates.
• Comparison snapshot (literature/generic):
  • AOM + H2O2 in H2O/EtOH: Low hazard oxidant, benign solvents; good for epoxidations and sulfide oxidations.
  • Sodium molybdate + organic peracids in chlorinated solvents: Higher hazard profile and waste burden; avoid when possible.
  • Heterogeneous MoOx/SiO2 catalysts prepared from AOM: Enable catalyst recovery/reuse, reducing dissolved metal discharge.
• Trade-offs:
  • H2O2 systems require careful control to prevent overoxidation and can present safety risks at high concentration.
  • Aqueous systems may limit substrate scope; phase-transfer strategies may be necessary.

Item-specific environmental metrics are not specified; practitioners should perform E-factor and PMI assessments for their process.

Pharmaceutical Uses

No therapeutic applications are claimed. The following reflects general, non-clinical, manufacturing-oriented uses reported in the literature for molybdate salts.

• Role in process chemistry (literature/generic):
  • Catalyst precursor for selective oxidations and oxidative workups in API intermediate synthesis when aqueous, low-residue systems are desired.
  • Source of Mo for preparing supported MoOx catalysts used in fine-chemical manufacturing steps.
• Excipients and pharmacopeia:
  • Ammonium octamolybdate is not a common pharmacopeial excipient. No item-specific pharmacopeial status is provided here; refer to regulatory guidance if considering use in GMP contexts.
• Advantages of ammonium counterion (manufacturing):
  • Volatile upon calcination, reducing risk of alkali contamination in products and processing equipment.
• Handling in GMP settings (general):
  • Control of trace metals and hydration level may be critical; specify via ICP and TGA on the CoA.

Item-specific regulatory grade, residual solvent limits, and compendial compliance are not specified for this product; consult the CoA/Spec Sheet and your quality unit.

Physical Properties

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet. (Common literature form: (NH4)4Mo8O26·4H2O.)
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet. (Literature for tetrahydrate ~1235 g/mol; varies with hydration.)
• Melting point / thermal behavior (literature): Polyoxomolybdate salts generally do not show a sharp melting point; they dehydrate upon heating and then decompose to MoO3/MoOx at elevated temperature rather than melt.
• Boiling point: Not applicable (inorganic salt; decomposes before boiling; literature/generic).
• Density: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility (literature/generic):
  • Water: Readily soluble; solubility and speciation depend strongly on pH and ionic strength. At neutral to slightly basic pH the octamolybdate anion is favored; at higher dilution or higher pH monomeric/dimeric molybdate can predominate.
  • Alcohols: Sparingly soluble in lower alcohols; dissolution typically requires some water.
  • Nonpolar solvents: Insoluble.
• pKa/logP/refractive index: Not applicable or not typically reported for inorganic polyoxoanions; Not specified for this item; refer to CoA/Spec Sheet.
• Hygroscopicity (literature/generic): Hydrated salts can slowly lose/gain water with ambient humidity; maintain closed containers to minimize hydration changes.

All quantitative specifications (e.g., exact hydration level, assay, trace metals, water) are not specified for this item here; consult the CoA/Spec Sheet for definitive values.

Quality & Grades

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• What “grade” implies (general guidance):
  • For inorganic salts used in catalysis and analytical chemistry, common grades include technical, reagent grade (AR), and high-purity/trace-metal grades. Higher grades specify tighter limits on metallic impurities (e.g., alkali/alkaline earth, transition metals), moisture, ignition residue, and assay by TGA or ICP-OES.
  • Chromatography-grade designations are uncommon for polyoxometalates; instead, trace-metal content and hydration consistency are often the critical parameters.
• Stabilizers: Not applicable; ammonium octamolybdate is typically supplied neat without organic stabilizers. If any stabilizer or anti-caking agent is present, it will be listed on the CoA/Spec Sheet (not specified here).
• What to check on receipt (practical tips):
  • Hydration state by TGA or Karl Fischer (if moisture-sensitive workflow).
  • Assay (as Mo or as AOM), insoluble matter, and pH of a defined aqueous solution to confirm speciation.
  • Trace metals by ICP, especially if used as a catalyst precursor for sensitive transformations.
• Documentation: For item-specific specifications (assay, water, residual metals, particle size), see the CoA/Spec Sheet accompanying the batch.

Reaction & Applications

Ammonium octamolybdate (AOM) is a versatile, water-compatible molybdenum(VI) source and polyoxometalate precursor used across catalysis, materials, and analysis.

• Catalysis and oxidation chemistry (literature):
  • Precursor to peroxomolybdate catalysts upon treatment with H2O2 for selective oxidations (alkene epoxidation, sulfide → sulfoxide/sulfone, alcohol → carbonyl under appropriate co-catalysts).
  • Forms active species for oxidative desulfurization of fuels in biphasic media with phase-transfer promoters.
  • Supports heterogeneous catalyst preparation: impregnation/calcination on oxides (SiO2, Al2O3, TiO2) to give MoOx domains for olefin metathesis (after activation with W/Co/Ni promoters as appropriate) and selective oxidations.
• Materials synthesis (literature):
  • Solution precursor to MoO3 thin films and nanostructures via spin/dip coating and thermal conversion.
  • Starting reagent for mixed molybdate ceramics and polyoxometalate assemblies.
• Analytical chemistry (literature):
  • Component in formation of phosphomolybdate/silicomolybdate complexes; used in colorimetric assays for phosphate and silicate (molybdenum blue method with reduction step).
• Advantages of the ammonium counterion (literature/generic):
  • Volatile upon heating (NH3/N2), facilitating clean conversion to oxide without residual alkali contamination—important for electronic/optical materials.
• Practical tips:
  • Control pH (typically 4–7) to maintain desired polymolybdate speciation; use ammonium buffers or dilute NH4OH.
  • For peroxo systems, add H2O2 slowly at low–moderate temperatures in water or water–alcohol mixtures; monitor by UV–vis (peroxo bands) when needed.

Manufacturer application text: Not provided; the above expands on commonly reported uses in the literature.

Reaction Conditions

The following are literature-reported, general conditions where ammonium octamolybdate (AOM) or molybdate derived from it is effective. They are guidelines only; optimize for your substrates.

• Peroxomolybdate oxidations (literature):
  • Formation: Combine AOM with 30–50% H2O2 in water or water–alcohol at 0–25°C; yellow to orange peroxo complexes form. Maintain pH near neutral to slightly acidic.
  • Alkene epoxidation: Substrate in CH3CN/H2O or EtOH/H2O (1:1 to 4:1 v/v), catalytic Mo (0.1–2 mol%), H2O2 (1.1–1.5 equiv per alkene O), 0–40°C, 0.5–6 h. Typical reported isolated yields: good to excellent for electron-rich alkenes; allylic oxidation can compete in some cases.
  • Sulfide oxidation: Similar media with 1.0–1.2 equiv H2O2 per S→O step, ambient temperature, minutes to hours; high selectivity to sulfoxide at low oxidant equivalents.
• Oxidative desulfurization (literature):
  • Biphasic model fuels with AOM/H2O2 in aqueous phase; phase-transfer agent (e.g., quaternary ammonium salt) and 30–60°C often used to accelerate mass transfer.
• Material preparation (literature):
  • MoO3 films: Spin/dip coat aqueous AOM solution onto substrate; dry at 80–120°C; calcine 350–500°C in air to convert to MoO3 (ramp rates 1–5°C/min to avoid cracking).
• Speciation control:
  • Buffer near pH 4–7 to favor polymolybdate; add NH4OH to prevent over-depolymerization at high dilution.

These are representative literature conditions; no item-specific process validation is provided. Always perform small-scale trials and safety assessments (especially when using concentrated H2O2).

Safety & Handling

• GHS classification: Not specified for this item; refer to SDS.
• Signal word / H-statements / pictograms: Not specified for this item; refer to SDS.
• General hazards (literature/generic for molybdate salts):
  • May cause irritation to skin, eyes, and respiratory tract upon contact or inhalation of dust.
  • Ingestion or chronic overexposure to soluble molybdenum compounds can have systemic effects; handle to minimize exposure.
  • Aquatic toxicity is possible for molybdate species; avoid environmental release.
• PPE recommendations (good laboratory practice):
  • Wear lab coat, safety glasses/goggles, and appropriate chemical-resistant gloves (e.g., nitrile).
  • Use dust control and local exhaust; avoid generating aerosols or dust.
• Handling notes:
  • Keep container tightly closed to limit moisture exchange that can alter hydration state.
  • Avoid contact with strong acids that can transform molybdate into heteropolyacids, and with strong reducing agents that can reduce Mo(VI) to lower oxidation states.
• First aid overview (consult SDS for details):
  • Eye/skin contact: Rinse with water for several minutes; remove contaminated clothing; seek medical attention if irritation persists.
  • Inhalation: Move to fresh air; seek medical attention for symptoms.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical advice.
• Fire and reactivity (literature/generic):
  • Nonflammable inorganic salt; use extinguishing media suitable for surrounding materials.
  • Thermal decomposition may release nitrogen oxides and molybdenum oxides.

Always consult the product SDS for authoritative, item-specific safety information and regulatory classifications.

Solvent Selection

This product is an inorganic polyoxometalate salt primarily used in aqueous media.

• Polarity and miscibility (literature/generic):
  • Best solvent: Water. Ammonium octamolybdate dissolves to give molybdate species whose distribution depends on pH and concentration.
  • Alcohols (MeOH, EtOH): Low to modest solubility; often require a water co-solvent to fully dissolve.
  • Acetonitrile, acetone: Limited direct solubility; use aqueous mixtures if needed.
  • Nonpolar solvents (ethers, hydrocarbons, chlorinated solvents): Insoluble.
• pH dependence (literature):
  • Slightly acidic to near-neutral aqueous solutions favor higher nuclearity species (octamolybdate and related isopolymolybdates).
  • At higher pH and/or low total Mo concentration, monomeric/dimeric molybdate prevail; adding NH4OH can shift equilibria.
• Practical selection tips:
  • For catalytic peroxomolybdate systems, water–alcohol or water–acetonitrile blends often balance solubility of substrate and catalyst.
  • For material preparation (e.g., MoO3 deposition), purely aqueous solutions are preferred for clean thermal conversion.
  • Maintain controlled ionic strength; ammonium as the counterion minimizes introduction of extraneous alkali metals compared with sodium/potassium molybdate.
• Alternatives:
  • If nonaqueous processing is mandatory, consider generating a peroxomolybdate complex in situ (with H2O2) that can be transferred into polar organics, or employ phase-transfer strategies.

Item-specific solubility numbers are not specified; consult the CoA/Spec Sheet and verify empirically for your matrix.

Storage & Reconstitution

• Storage conditions (item-specific):
  • Storage: Room temperature (per product data).
  • Shipped: Normal (per product data).
• Container and environment (general best practice):
  • Keep tightly closed in a dry place to minimize changes in hydration state. Protect from strong acids, bases (if not intended), and reducing agents.
• Stability (literature/generic):
  • Stable as a solid under ambient conditions. On prolonged exposure to humidity, the hydration level can drift; on heating, dehydration and conversion to MoO3 occur.
• Reconstitution/dissolution (general guidance):
  • Add the desired amount to deionized water with stirring. Typical working concentrations range from millimolar to molar in terms of total Mo, depending on the application.
  • Adjust pH with dilute NH4OH or buffer to maintain the desired polyoxomolybdate speciation; avoid strong acids unless heteropolyacid formation is desired.
  • For sterile applications (e.g., biological studies), sterile-filter through 0.2 µm after dissolution.
• Freeze–thaw: Not applicable to the dry solid. For aqueous solutions, store refrigerated for short periods and avoid repeated freeze–thaw to limit speciation changes and precipitation; prepare fresh when critical.

All item-specific specifications beyond storage/shipping (e.g., assay, water content, stabilizers) are not specified for this item; refer to the CoA/Spec Sheet. Research use only.

Structure & Identity

Ammonium octamolybdate is a polyoxometalate salt commonly supplied as the tetrahydrate and used as a source of molybdate clusters in aqueous and catalytic chemistry.

• Item-specific identifiers:
  • CAS: 12411-64-2
  • SKU: A302284
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Composition (literature):
  • Common empirical formula: (NH4)4Mo8O26·4H2O (tetrahydrate; literature)
  • Alternative way to view: 4 NH4+ countercations with an [Mo8O26]4− polyoxoanion (literature)
  • Molecular weight: Literature values for the tetrahydrate are ~1235 g/mol; exact value depends on hydration state (literature).
• Structural features (general description):
  • The anion is a polyoxomolybdate cluster built from corner- and edge-sharing MoO6 octahedra, forming the [Mo8O26]4− framework (literature).
  • Counterions: Four ammonium cations (NH4+) balance the 4− charge of the octamolybdate cluster (literature).
  • Hydration: Frequently isolated with coordinated/entrained water (commonly 4 H2O; literature).
• 2D structure in words (literature/generic):
  • Central motif: an assembly of eight Mo(VI) centers each in octahedral MoO6 environments linked via shared oxo bridges (μ2-O, μ3-O), yielding a compact, oxygen-rich anion.
  • Peripheral ammonium ions hydrogen-bond to terminal and bridging oxo ligands; lattice waters further stabilize the network.

Note: Exact hydration state, formula rendering, and any structure identifiers for this catalog item are not specified here; consult the CoA/Spec Sheet for definitive item-specific identity details.

Synthetic Utility

As a polyoxomolybdate source, ammonium octamolybdate provides Mo(VI) in a form that is easy to dissolve, transform, and deposit, enabling both homogeneous and heterogeneous transformations.

• Functional reactivity (literature):
  • Oxidation chemistry: In situ formation of peroxomolybdate with H2O2 catalyzes alkene epoxidation, sulfide oxidation, and alcohol oxidation (with cocatalysts such as quaternary ammonium salts or phase-transfer agents).
  • Heteropoly/iso-poly equilibria: pH-controlled assembly/disassembly allows access to different nuclearities, tuning redox potential and acidity for specific transformations.
  • Precursor utility: Impregnation of supports with AOM solutions followed by drying/calcination generates MoOx domains for selective oxidation and metathesis catalysts.
• Retrosynthetic value (literature/generic):
  • Provides a clean, ammonium-based Mo source to avoid sodium/potassium residues in sensitive downstream steps (e.g., materials or catalytic systems where alkali poisons activity).
• Named/representative systems:
  • Venturello (peroxophosphotungstate/molybdate-type) systems adapted with AOM to generate active peroxo species in biphasic oxidations.
  • Aqueous H2O2–AOM epoxidations of allylic/isolated alkenes at ambient temperature with appropriate surfactants or co-solvents.
• Practical notes:
  • Control water content and pH for reproducible speciation.
  • Remove ammonium residues by gentle calcination or vacuum drying if preparing oxide materials.

No item-specific catalytic activity metrics, surface areas, or impurity profiles are provided; confirm performance under your conditions.

Target Specificity

Not applicable. This product is a small-molecule inorganic salt, not an antibody, enzyme, or targeted biological reagent.

• Antigen/epitope, species reactivity, clone, and isotype: Not relevant.

For application-focused details, see Reaction & Applications, Synthetic Utility, and Reaction Conditions.