Palladium

• CAS: 7440-05-3
• Catalog Number: ACM7440053-27
• Category: Main Products
• Molecular Weight: 106.42
• Molecular Formula: Pd
• Description: Palladium on carbon, often referred to as Pd/C, is a form of palladium used as a catalyst. The metal is supported on activated carbon in order to maximize its surface area and activity.
• Synonyms: ESCAT 1391;ESCAT 1371;ESCAT 1351;Paladium;PALLIDIUM
• IUPAC Name: palladium
• Canonical SMILES: [Pd]
• InChI: 1S/Pd
• InChI Key: KDLHZDBZIXYQEI-UHFFFAOYSA-N
• Boiling Point: 2963 °C
• Melting Point: 1555ºC
• Density: 1.025 g/mL at 25ºC
• Solubility: Soluble in aqua regia and fused alkalies; insoluble in organic acids
• Appearance: Powder
• Application: Among the platinum group metals, palladium is the least noble metal, exhibiting greater reactivity than other metals of the group. The metal forms mostly bivalent compounds, although a small number of tetravalent and a fewer trivalent compounds are known. Palladium exhibits a strong tendency to form complexes, most of which are four-coordinated square planar complexes of the metal in +2 oxidation state. When heated in air or oxygen above 350°C, palladium forms a black oxide, PdO coated over its surface. On further heating to over 790°C, the oxide decomposes back to the metal. Palladium dissolves more oxygen in molten state than in solid form.; ; Palladium reacts with fluorine and chlorine at 500°C forming its halides, the black PdF3 and the red deliquescent solid PdCl2.; ; Palladium is attacked by concentrated nitric acid, particularly in the presence of nitrogen oxides. The reaction is slow in dilute nitric acid. Finely divided palladium metal reacts with warm nitric acid forming palladium(II) nitrate, Pd(NO3)2. Hydrochloric acid has no affect on the metal. Reaction with boiling sulfuric acid yields palladium sulfate, PdSO4, and sulfur dioxide.; ; Palladium readily dissolves in aqua regia forming chloropalladic acid, H2PdCl6. Evaporation of this solution yields palladium(II) chloride, PdCl2.; ; Palladium absorbs hydrogen over 800 times its own volume over a range of temperature. By doing so, the metal swells, becoming brittle and cracked. Such absorption of hydrogen decreases the electrical conductivity of the metal. Also, such absorption activates molecular hydrogen, dissociating it to atomic hydrogen.
• Storage: room temp
• Assay: 99.995% trace metals basis
• Color/Form: Silver-white, ductile metal;Steel white;Silver-white metal; cubic
• Complexity: 0
• Covalently-Bonded Unit Count: 1
• Decomposition: No decomposition. /from table/
• EC Number: 231-115-6
• Exact Mass: 105.90348g/mol
• Form: powder
• Formal Charge: 0
• Hazard Codes: Xn
• H-Bond Acceptor: 0
• H-Bond Donor: 0
• Heavy Atom Count: 1
• HS Code: 7110210000
• MDL Number: MFCD00011167
• Monoisotopic Mass: 105.90348g/mol
• Other Experimental: Palladium is the lightest of the platinum group and very malleable and ductile when pure. It resists oxidation at ordinary temperatures. It absorbs a considerable amount of hydrogen gas. It is appreciably volatile at high temperatures. At red heat it is converted to the oxide.;Stable isotopes: (102)Pd, 1.02%; (1.4)Pd, 11.14%; (105)Pd, 22.23%; (106)Pd, 27.33%; (108)Pd, 26.46%; (110)Pd, 11.72%;Usual valency, 2,4; ionic radius, 65 pm, crystal structure, face-centered cubic; lattice constant, 389 pm; reflectance, 54%; thermal expansion, 11.11X10+6 °C-1; magnetic susceptibility, 5.23X10-6 cu cm/g; work function, 4.99 eV; Young's modulus, 1.24X10+8 kN/sq m; ultimate tensile strength, 180-200 MPa; Poisson's ratio, 0.39; Vicker's hardness, 40; temperature coefficient of resistance 3.8X10-3 K-1; electrical resistivity at 0 °C, 9.93 microohm-cm; thermal conductivity, 75 W/m K;Palladium is stable in air, even at elevated temperatures; shows no corrosion or tarnishing in hydrogen sulfide atmospheres.;Enthalpy of formation at 298.15 K: 378.2 kJ/mol (gas); molar heat capacity at 298.15 K: 26.0 J/mol K (crystal), 20.8 J/mol K (gas);Enthalpy of fusion: 16.74 kJ/mol at 1554.9 °C
• Packaging: 1 g in glass bottle
• Quality Level: 100
• RIDADR: UN 3089 4.1/PG 2
• Rotatable Bond Count: 0
• Stability: Stable. Flammable - fine powder may cause fire or explosion in air. Incompatible with ozone, sodium tetrahydroborate, sulphur, arsenic.
• Storage Conditions: Store at RT.
• UNII: 5TWQ1V240M
• Vapor Pressure: 3.47 Pa (0.0260 mm Hg) at 1552 °C
• WGK Germany: -

Case Study

Biomedical Applications of Palladium Nanoparticles

Phan, Thi Tuong Vy, et al. Nanomaterials 10.1 (2019): 66.

Palladium nanoparticles (PdNPs) have intrinsic properties such as excellent catalytic, electronic, physical, mechanical and optical properties and a variety of shapes and sizes. Preliminary studies have shown that PdNPs have great potential in the development of novel photothermal agents, photoacoustic agents, antibacterial/antitumor agents, gene/drug carriers, prodrug activators and biosensors.
PdNPs have currently attracted considerable interest in the field of photothermal therapy (PTT) due to their high thermal stability and optical properties. PTT is a novel therapy that uses near-infrared (NIR) laser light absorbers to generate heat under NIR laser irradiation. The strong absorption of PdNPs in the NIR region maximizes the penetration of light into tissues. Taking advantage of the optical properties of the material, photoacoustic imaging (PAI) has also been recently developed as a new promising imaging technique for early tumor diagnosis and management. In order to enhance the photoacoustic signal from tissues, photoacoustic agents are usually required. With their inherent optical properties, PdNPs have recently been investigated as photoacoustic agents. The obtained results indicate the great potential of PdNPs as effective photoacoustic agents for PAI. Another major application of PdNPs in biomedicine is gene/drug delivery. The high surface area of PdNPs can load a large amount of drugs, stability and non-toxicity make them effective nanocarriers for genes/drugs or other small molecules. With their excellent photocatalytic properties, PdNPs have been found to act as prodrug activators.

Palladium-catalyzed cross-coupling in aqueous media

Shaughnessy, Kevin H., and Rebecca B. DeVasher. Current Organic Chemistry 9.7 (2005): 585-604.

Palladium-catalyzed cross-coupling reactions can occur using water as a solvent. Palladium-catalyzed coupling reactions are an efficient method for forming carbon-carbon and carbon-heteroatom bonds under mild conditions. Isolation of the catalyst from the organic product can be very difficult; however, confining the catalyst to the aqueous phase of an aqueous biphasic solvent system can potentially simplify catalyst recovery. A variety of new hydrophilic ligand structures have recently been introduced that are industrially relevant aryl bromides and chlorides.
Using palladium on carbon as the best catalyst, lithium in the presence of zinc as a reducing agent is able to achieve self-coupling of aryl iodides in air at room temperature in a water/acetone solvent mixture in good yields (80%). Aryl bromides and chlorides do not react under these conditions, although it was subsequently discovered that 18-crown-6 aryl bromide can achieve modest coupling yields. Self-coupling of aryl chlorides using palladium on carbon in the presence of formate or hydrogen as a reducing agent is performed in pure water at 100 °C. To achieve the best yields in pure water systems, surfactants such as polyethylene glycol (PEG) or cetyltrimethylammonium bromide (CTAB) are required. The aqueous catalyst solution can be reused three times without loss of activity. Kinetic studies of the self-coupling systems were performed using formic acid, hydrogen, or zinc as reducing agents in an attempt to determine the possible mechanism. A similar mechanism was proposed for all three systems involving single electron transfer (SET) from a palladium cluster to convert the aryl chloride to a radical anion. When the radical anion is located on the palladium surface, it dissociates the chloride to give an aryl radical, which self-couples with another aryl radical. The Pd(I) site is not proportional to Pd(0) and Pd(II).

Custom Q&A

What is the molecular formula of palladium?

The molecular formula of palladium is Pd.

What is the atomic number of palladium?

The atomic number of palladium is 46.

What is the atomic weight of palladium?

The atomic weight of palladium is 106.42 g/mol.

What are some synonyms for palladium?

Some synonyms for palladium are Palladium Black and Palladium on carbon.

What is the IUPAC name of palladium?

The IUPAC name of palladium is palladium.

What is the InChIKey of palladium?

The InChIKey of palladium is KDLHZDBZIXYQEI-UHFFFAOYSA-N.

What is the CAS number of palladium?

The CAS number of palladium is 7440-05-3.

What is the boiling point of palladium?

The boiling point of palladium is 2963 °C.

What is the melting point of palladium?

The melting point of palladium is 1554.9 °C.

What is the physical description of palladium?

Palladium can exist in the form of dry powder, liquid, pellets or large crystals, and other solid forms.