Cadmium bromide , CAS No.9816930

CAS: 9816930 Cat. No.: C965977 Fórmula: Br₂Cd Peso molecular: 272.220

Storage

Room temperature

Specifications

Condiciones de almacenamiento de almacenamiento

Room temperature

Nombres e identificadores

• Sonrisas canónicas: [Br-].[Br-].[Cd+2]
• IUPAC Name: cadmium(2+);dibromide
• InChIKey: KPWJBEFBFLRCLH-UHFFFAOYSA-L
• INCHI: 1S/2BrH.Cd/h2*1H;/q;;+2/p-2
• Peso molecular: 272.220

Taxonomic Classification

Taxonomy Tree

• Kingdom Inorganic compounds
  • Superclass Mixed metal/non-metal compounds
    • Clase Transition metal salts
      • Subclass Transition metal bromides

• Kingdom: Inorganic compounds
• Superclass: Mixed metal/non-metal compounds
• Clase: Transition metal salts
• Subclass: Transition metal bromides
• Intermediate Tree Nodes: Not available
• Direct Parent: Transition metal bromides
• Alternative Parents: Inorganic cadmium salts
• Molecular Framework: Not available
• Substituents: Transition metal bromide - Inorganic cadmium salt - Inorganic salt
• Descripción: This compound belongs to the class of inorganic compounds known as transition metal bromides. These are inorganic compounds in which the largest halogen atom is Bromine, and the heaviest metal atom a transition metal.
• External Descriptors: Not available

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

Propiedades químicas y físicas

• Peso molecular: 272.220 g/mol
• Hydrogen Bond Donor Count: 0
• Hydrogen Bond Acceptor Count: 2
• Rotatable Bond Count: 0
• Exact Mass: 273.738 Da
• Monoisotopic Mass: 271.74 Da
• Topological Polar Surface Area: 0.000 Ų
• Heavy Atom Count: 3
• Formal Charge: 0
• Complexity: 0.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 0
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 3

XLogP3

Application Protocols

Not applicable.

• No immunoassay or bioanalytical kit protocols are associated with this inorganic salt. For synthetic or materials workflows, refer to the Reaction Conditions tab for generalized procedural guidance and adjust to your system and scale.

Biological Roles

Applicability

• Cadmium bromide has no beneficial biological role. Cadmium is a non-essential, highly toxic metal ion in biological systems.

Literature overview (not a clinical claim)

• Mechanistic toxicology: Cd2+ can displace essential divalent cations (e.g., Zn2+, Ca2+), bind thiol-rich sites in proteins, and disrupt redox homeostasis. It accumulates in tissues due to slow excretion and binding to metallothioneins.
• Enzyme interactions: Inhibits numerous metalloenzymes by mismetallation; may induce oxidative stress pathways and unfolded protein responses.
• Cellular handling: Cells sequester Cd2+ via metallothionein induction and vacuolar/lysosomal compartmentalization; bromide acts primarily as a counterion and is not considered the toxic driver.

Practical guidance

• Use only for in vitro or ex vivo research where cadmium exposure is controlled. Do not use for any clinical or diagnostic applications.
• When studying metal–protein interactions or toxicology, rigorously quantify free Cd2+ using appropriate chelators/buffers and account for complexation by medium components.

Buffer Applications

Not typically applicable.

• Cadmium bromide is not used as a buffering agent. In aqueous solutions it behaves as a simple electrolyte and may acidify/basicify only through minor hydrolysis under extreme pH.
• If present in buffered systems (e.g., for controlled precipitation or coordination studies), select buffers without strong chelating groups that would sequester Cd2+ (avoid citrate, EDTA). Use acetate or chloride media when free Cd2+ is required, and verify speciation by calculation.

Green Alternatives

Context

• Cadmium compounds pose significant health and environmental hazards. Substitution and process intensification should be prioritized where performance allows.

Potential alternatives (literature comparison)

• Zinc or magnesium halides (e.g., ZnBr2, MgBr2): Often serve similar Lewis-acid or halide-source roles with substantially lower toxicity. In acylation chemistry, organozinc reagents can substitute for organocadmiums, albeit sometimes with different chemoselectivity.
• Copper or nickel catalysts: In cross-coupling and halide exchange, modern catalysts may obviate the need for cadmium salts.
• For semiconductor/perovskite research: Where Cd-based optoelectronic properties are not essential, consider Pb-free, Cd-free systems (e.g., Zn, In, Sn halides) or I–III–VI materials. Note, however, that cadmium imparts unique electronic structures not trivially replicated.

Trade-offs

• Performance: Organocadmium reagents offer high selectivity for ketone synthesis from acyl chlorides; organozinc reagents can be less reactive and may require catalysts or elevated temperatures.
• Materials properties: Cd-based II–VI semiconductors exhibit specific band gaps and high-quality emission; replacing Cd typically alters optoelectronic performance and may require process redevelopment.

Process improvements if substitution is not feasible

• Minimize inventory and scale; enclose operations.
• Switch from aqueous to ligand-assisted nonaqueous processing to reduce effluent volumes.
• Implement closed-loop solvent recovery and dedicated heavy-metal waste capture.
• Document and follow a cadmium exposure control plan per institutional EHS.

Pharmaceutical Uses

Not typically applicable.

• Cadmium salts are generally prohibited in pharmaceutical formulations owing to toxicity and strict ICH/USP elemental impurity limits. Cadmium bromide is not used as an excipient.
• If handled in pharmaceutical research environments, it would be limited to analytical standards or process development studies under containment, with validated decontamination and waste procedures. No pharmacopeial monograph context is provided for this item.

Physical Properties

Item-specific (from Product Data)

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.

Literature/General properties (not item specifications; hydrate state dependent)

• Phase: Solid, inorganic salt.
• Melting point (anhydrous, literature): ~567 °C; hydrates decompose on heating.
• Boiling/sublimation (literature): Decomposes before boiling; halide loss at elevated T.
• Density (anhydrous, literature): ~5.2 g/cm³ at 25 °C.
• Solubility (literature): Highly soluble in water; soluble in alcohols; limited solubility in nonpolar solvents. Hydrates are very water-soluble.
• Hygroscopicity: Tends to absorb moisture and form hydrates in humid air.
• Conductivity: Aqueous solutions conduct via Cd2+ and Br−.
• Refractive index: Not typically reported for bulk solid; solutions follow electrolyte behavior.
• pKa: Not applicable (salt of strong acid/base); hydrolysis negligible in neutral media but increases in basic solutions due to Cd(OH)2 formation.
• Partitioning: Not applicable (ionic). LogP not meaningful; use distribution in aqueous phases.

Practical notes

• Because properties vary with hydration state and impurity profile, verify exact values for your lot on the CoA/Spec Sheet before designing processes with tight thermal or solubility constraints.

Quality and Grades

Item-specific (from Product Data)

• Grade/purity: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/additives: Not specified for this item; refer to CoA/Spec Sheet.
• Shipped in: Not specified for this item; refer to CoA/Spec Sheet.

General guidance for this compound class

• Cadmium bromide is an inorganic salt; typical catalog offerings include technical-grade (suitable for general synthesis), analytical-reagent grade (tight metal impurity and halide assay specifications), and electronic/materials grades (trace-metal basis for optoelectronic precursors). UV cutoff and HPLC absorbance specifications are generally not relevant unless intended for photophysical studies.
• Hydration state matters: Anhydrous vs. hydrates (e.g., tetrahydrate) influence assay by mass and solubility. Verify hydration on the CoA; calculations for stoichiometry and solution prep should account for waters of crystallization.
• Trace metals: For materials chemistry (e.g., perovskites, QDs), low alkali/transition-metal contamination can be critical; seek “trace metals basis” specs where needed. Since no item-specific impurity data are provided here, confirm limits on the Spec Sheet.
• Lot-specific documentation: Always defer to the item’s CoA for assay (%), halide content, loss on drying, and hydration state before quantitative work.

Reaction and Applications

Representative uses (literature; for research use only)

• Precursor to organocadmium reagents: CdBr2 reacts with organolithium or Grignard reagents to generate R–Cd–Br or R2Cd species, which can acylate acid chlorides to give ketones with reduced over-addition compared to Grignards. Due to toxicity, this chemistry has largely been superseded but remains a benchmark transformation in synthesis methodology.
• Lewis acid/promoter: Cadmium(II) halides can function as soft Lewis acids, activating substrates (e.g., acylations, halide exchange) and facilitating coupling/condensation in select contexts.
• Materials chemistry: Widely used as a cadmium source where bromide is desired or tolerated—synthesis of II–VI semiconductors (e.g., CdSe/CdS systems with bromide ligands), layered halide perovskites, and in the preparation of cadmium bromide complexes for optoelectronic precursor inks. Bromide counterions assist in surface passivation and halide stoichiometry control.
• Analytical chemistry: Standard for halide/cadmium precipitation reactions (e.g., formation of CdS) and complexometric/ligand screening studies due to predictable Cd2+ coordination chemistry.
• Historical photographic processes: Cadmium bromide served as a component in certain emulsion preparations; modern use is limited by hazard regulations.

Practical considerations

• Anhydrous handling: For organometallic applications, rigorously dry solvents and apparatus; exclude moisture/air. Hydrates will quench reactive carbanions.
• pH control: In aqueous media, maintain acidic to neutral pH to avoid Cd(OH)2 precipitation.
• Waste: Capture all cadmium-containing residues for hazardous disposal; avoid sulfide releases unless in controlled waste treatment.

Reaction Conditions

General guidance from literature (not item specifications)

• Formation of organocadmium reagents: Combine CdBr2 (anhydrous) with 2 equivalents of RLi or RMgX in dry THF or Et2O at −78 to 0 °C under inert atmosphere; then add acyl chloride at low temperature and warm to 0–25 °C. Typical reaction times range from 0.5–3 h after acyl chloride addition. Workups must quench residual organometallics carefully and collect cadmium wastes.
• Salt metathesis to CdS/CdSe nanomaterials: Dissolve/complex CdBr2 in coordinating solvent (e.g., oleylamine, TOP/TOPO, or octadecene with ligands) at 120–250 °C, inject chalcogen precursor (e.g., TOP–Se or H2S surrogate) and grow nanocrystals by temperature/time control. Bromide can influence surface states; ligand ratios control size/dispersity.
• Coordination complex synthesis: Reflux CdBr2 with neutral ligands (bipyridine, phen, amines) in ethanol/DMF; crystallize complexes by slow diffusion or vapor layering. Stoichiometry (1:2 or 1:3 ligand:Cd) determines geometry.
• Aqueous precipitation: For analytical or materials precursors, add sulfide/selenide source to acidic CdBr2 solution at room temperature to form CdX (X = S, Se) precipitates; control pH and nucleation with surfactants if nanoscale products are desired.

Key variables

• Exclude moisture for organometallic steps; deliberately include coordinating ligands for materials routes.
• Manage pH to avoid Cd(OH)2 in basic media.
• Always use inert atmosphere where air/moisture sensitivity or oxidation state control is required.

Safety and Handling

Item-specific (from Product Data)

• GHS Classification / Signal word / H-statements / Pictograms: Not specified for this item; refer to the SDS.
• Storage conditions: Room temperature (per Product Data).

Literature/General safety guidance (consult SDS for authoritative details)

• Hazard profile: Cadmium compounds are highly toxic, carcinogenic, and environmentally hazardous. Expected GHS elements typically include Acute Tox., Carc., Repr. Tox., STOT-RE, and Aquatic Chronic; handle as a severe toxicant even if not item-listed.
• Exposure routes: Inhalation of dust, ingestion, and skin contact. Avoid aerosolization and dust generation; use closed handling where possible.
• PPE: Laboratory coat, chemical-resistant gloves (e.g., nitrile), splash goggles; work in a certified chemical fume hood. For weighing, use antistatic measures and local exhaust.
• Incompatibilities: Strong bases (precipitation of Cd(OH)2), sulfide sources (formation of CdS), strong oxidizers (bromine release possible under extreme conditions). Avoid contact with acids that release HBr in confined spaces.
• Environmental controls: Prevent release to the environment. Collect aqueous wastes containing Cd2+ for regulated hazardous waste disposal; chelation or sulfide precipitation may be used in treatment under permit.
• First aid (overview): If inhaled—move to fresh air, seek medical attention. Skin/eye contact—immediately flush with water for 15 minutes; remove contaminated clothing. If ingested—rinse mouth, seek urgent medical attention. Do not induce vomiting unless instructed by medical personnel.
• Fire: Not combustible; in fire conditions, cadmium/halide fumes may form—firefighters should use self-contained breathing apparatus.

Solvent Selection

Applicability

• As an ionic cadmium(II) salt, cadmium bromide is primarily used in aqueous or polar donor solvents; solvent choice drives solubility and coordination chemistry.

General solvent behavior (literature)

• Water: High solubility; enables straightforward preparation of Cd2+ solutions for analytical or precipitation chemistry.
• Alcohols (MeOH, EtOH, i-PrOH): Generally soluble; donor ability supports Cd2+ coordination.
• Polar aprotics (DMSO, DMF, NMP): Very good solubility; strong coordination can alter reactivity and spectroscopic signatures.
• Ethers (THF, dioxane): Limited to moderate solubility; improved in presence of co-ligands (e.g., amines) that solvate Cd2+.
• Nonpolar solvents (hexanes, toluene): Insoluble; use phase transfer or convert to organometallic/ligated forms.

Selection guidance

• For salt metathesis and precipitation studies: Use water or alcohols; control ionic strength and pH to manage Cd(OH)2 formation in basic media.
• For organocadmium reagent preparation: Ethereal solvents (THF/Et2O) under anhydrous conditions are common, with CdBr2 serving as Cd2+ source in situ with RLi/RMgX.
• For materials synthesis (e.g., perovskites, QDs): Coordinating, high-boiling media (oleylamine, trioctylphosphine, octadecene mixtures) are used; pre-solubilization of CdBr2 may require ligands (amines, carboxylates) to form soluble complexes.

Comparison snapshot (literature)

• Water vs. DMF/DMSO: Water maximizes ionic mobility; DMF/DMSO provide stronger coordination, suppressing hydrolysis and enabling nonaqueous processing.

Storage and Reconstitution

Item-specific (from Product Data)

• Storage conditions: Room temperature.

General best practices for this compound class

• Moisture sensitivity: Cadmium bromide forms hydrates; keep container tightly closed in a dry place. Consider desiccation (P2O5 or silica gel) to maintain anhydrous state if required by your application.
• Light/air: Stable to air and ambient light as a solid; avoid prolonged exposure to humid air.
• Container: Store in chemically resistant, well-sealed bottles; segregate from foods and incompatible chemicals.
• Spill control: Handle powders over trays; clean with HEPA-filtered vacuum or wet methods to avoid dust.

Reconstitution guidance (literature)

• Aqueous stock solutions: Prepare in deionized water to desired molarity; mildly acidic conditions (e.g., 0.01–0.1 M HCl) can suppress hydrolysis/precipitation in long-term stocks. Filter through 0.2 µm if particulate is present.
• Organic solutions: To solubilize in polar aprotics (DMF/DMSO) or with ligand assistance (amines, carboxylates). For air-sensitive uses, prepare under inert gas with anhydrous solvents.
• Storage of solutions: Use glass or compatible plastics; store at ambient temperature or 2–8 °C depending on matrix. Clearly label as cadmium-containing hazardous solution and assign limited shelf-life.

Always consult the product’s CoA and SDS for lot-specific guidance on hydration state, solubility, and safe handling during storage and use.

Structure and Identity

Item-specific (from Product Data)

• Product name: Cadmium bromide (SKU: C965977)
• CAS: 9816930
• InChIKey: 186447
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.

Literature/General identity (for reference; not item specifications)

• Common formula: CdBr2 (anhydrous); hydrates are known (e.g., CdBr2·4H2O).
• Typical structure: Cadmium(II) bromide is an ionic cadmium(II) halide. The solid commonly adopts a layered CdCl2-type lattice in which each Cd2+ is octahedrally coordinated by six bromide ions in edge-sharing sheets; Br− is three-coordinate within the layer. Hydrates feature aquo-coordination at Cd2+.
• 2D description in words: A central divalent cadmium cation charge-balanced by two bromide anions; as a solid, repeating CdBr6 octahedra form sheets (…Br–Cd–Br…) with van der Waals gaps between layers.

Notes

• This product is listed under Life Science category but is an inorganic salt typically used in synthesis, materials, and analytical workflows.
• Where exact identifiers (SMILES, precise InChIKey variant, hydrate state) are required for regulatory or analytical purposes, consult the specific CoA/SDS for this lot.

Synthetic Utility

Functional profile (literature)

• Soft Lewis acid: Cd2+ coordinates to soft donor atoms (S, N, π-systems), enabling activation in select condensations and rearrangements.
• Halide source and counterion: Br− can participate in halide exchange, crystal engineering, and lattice templating for halide perovskites or coordination polymers.
• Organocadmium chemistry: Reaction of CdBr2 with RLi/RMgX affords organocadmium intermediates that acylate acid chlorides to ketones with high selectivity and reduced addition to aldehydes/ketones compared to Grignards.
• Salt metathesis: Useful in preparing cadmium chalcogenides (e.g., CdS, CdSe) via reaction with sulfide/selenide sources from solution or solvothermal conditions; bromide aids in solubility and surface passivation.

Retrosynthetic value

• For ketone synthesis from carboxylic acid derivatives where over-addition is problematic, a retrosynthetic disconnection via acid chloride + organocadmium is classical (now often replaced by organozinc/copper-catalyzed variants due to EHS concerns).

Practical notes

• Hydration state control is critical: Water bound to Cd2+ will quench organometallics and alter coordination equilibria. Drying under vacuum at moderate temperature or purchasing anhydrous grades is standard for air-sensitive applications.
• Ligand design: Amines, phosphines, and carboxylates form defined Cd(II) complexes from CdBr2, enabling solubilization in organic media for materials precursor routes.

Target Specificity

Not applicable.

• This product is an inorganic salt, not an antibody, enzyme, or affinity reagent. No antigen/epitope or species reactivity is relevant to cadmium bromide.