7440-43-9 Usage
Description
Cadmium is a grey-white, soft, blue-white malleable, lustrous metal. It is insoluble in cold water, hot water, methanol, diethyl ether, and n-octanol. It is stable and incompatible with strong oxidising agents, nitrates, nitric acid, selenium, and zinc, and the powdered metal may be pyrophoric and flammable.
Cadmium is associated with occupations such as industrial processes, metal plating, and production of nickel– cadmium batteries, pigments, plastics, and other synthetics. Cadmium metal is produced as a by-product from the extraction, smelting, and refining of the non-ferrous metals zinc, lead, and copper. In view of the unique properties, cadmium metal and cadmium compounds are used as pigments, stabilisers, coatings, specialty alloys, and electronic compounds.
Chemical Properties
Different sources of media describe the Chemical Properties of 7440-43-9 differently. You can refer to the following data:
1. Calmium is an odorless, silver-white lustrous metal with a bluish tinge, which is ductile and highly malleable with a melting point of 321 °C. The metal is soft enough to cut with a knife and will tarnish in air; as a powder, cadmium is flammable. Burning cadmium results in an odorless yellowbrown cadmium fume (cadmium monoxide or cadmium oxide fume) composed of finely divided particles dispersed in air. Both cadmium and cadmium oxide are insoluble in water and have a vapor pressure of approximately 0 mmHg. Cadmium is insoluble in water but can be solubilized in acid. Cadmium salts (e.g., cadmium sulfate and cadmium chloride) are soluble in water.
2. Elemental cadmium has a hexagonal crystal structure. Cadmium is a silver-white metal, malleable and ductile, but at 80 C becomes brittle. It remains lustrous in dry air and is only slightly tarnished by air or H2O at standard conditions. The element may be sublimed in a vacuum at a temperature of about 300 C, and when heated in air burns to form the oxide. Cadmium dissolves slowly in hot dilute HCl or H2SO4 and more readily in HNO3. Naturally occurring isotopes 106, 108, 110 114, 116. 113Cd is unstable with respect to beta decay (0.3 MeV) into 113In (t1/2 1013 years).In virtually all of its compounds, cadmium exhibits the +2 oxidation state, although compounds of cadmium(I) containing the ionCd2 2+, have occasionally been reported. Cadmium hydroxide is more basic than zinc hydroxide, and only slightly amphiprotic, requiring very strong alkali to dissolve it, and forming Cd(OH)3 or Cd(OH)4 2 depending upon the pH.
Physical properties
Cadmium is a soft, blue-white metal that is malleable and ductile although it becomesbrittle at about 80°C. It is also found as a grayish-white powder. It is considered rare and isseldom found by itself as an ore. Its melting point at 320.9°C is considered low. Its boilingpoint is 765°C, and its density is 8.65 g/cm3. Certain alloys of cadmium have extremely lowmelting points at about 70°C.
Isotopes
There are 52 isotopes of cadmium. Forty-four are radioactive and artificiallyproduced, ranging from Cd-96 to Cd-131. Of these 52 isotopes, there are five stableisotopes plus three naturally occurring radioactive isotopes with extremely long half-livesthat are considered as contributing to the element’s natural occurrence in the Earth’scrust. The three naturally radioactive isotopes (Cd-106, Cd-113, and Cd-116) are thelongest known beta emitters. They are two million years older than when the solar systemwas formed about 4.5 billion years ago. The five stable isotopes and their proportionalcontributions to the element’s existence on Earth are as follows: Cd-108 = 0.89%,Cd-110 = 12.49%, Cd-111= 12.80%, Cd-112 = 24.13%, and Cd-114 = 28.73%.
Origin of Name
The word cadmium is from the Latin word cadmia or the Greek word
kadmeia, meaning the zinc oxide ore “calamine” that contains the element cadmium.
Occurrence
Cadmium is considered a rare element even though it is widely distributed over the Earth’scrust. Its estimated abundance in the Earth’s crust is 1.10-1 milligrams per kilogram. It is consideredthe 65th most abundant element, but it does not occur as a free metal in nature. It isusually found in relationship with other metallic ores. Its abundance is only about 1/1000ththat of zinc. It is found in an ore called greenockite, which is cadmium sulfite (CdS). This oredoes not have a high enough concentration of cadmium to be mined profitably. Cadmiumis found along with zinc, lead, and copper ores. Today, most cadmium is obtained as a byproductfrom the processing and refining of zinc ores. In addition, dust and fumes from roastingzinc ores are collected by an electrostatic precipitator and mixed with carbon (coke) andsodium or zinc chloride. This residue is then treated to recover the cadmium. Other refiningprocesses can obtain up to 40% recovery of cadmium from zinc ores.Greenockite ore, as well as zinc and other ores, which produce cadmium as a by-product,are found in many countries, including Australia, Mexico, Peru, Zaire, Canada, Korea, andBelgium-Luxembourg and in the central and western United States.
Characteristics
Although cadmium is not considered a transition element in some periodic tables, it is thecentral element of the triad with zinc and mercury. Zinc is just above it and mercury is below itin group 12 of the periodic table. Cadmium’s chemical and physical properties are similar to itsgroup 12 mates. Their electronegativity is very similar: Zn = 1.6, Cd = 1.7, and Hg = 1.9.Cadmium is resistant to alkalis, but is soluble in acids, mainly nitric acid. Although it isused to electroplate steel to prevent corrosion, it will tarnish in moist air.
History
Cadmium was discovered by Stromeyer in 1817 from an impurity in zinc carbonate.
Cadmium most often occurs in small quantities associated with
zinc ores, such as sphalerite (ZnS). Greenockite (CdS) is the
only mineral of any consequence bearing cadmium. Almost all
cadmium is obtained as a by-product in the treatment of zinc,
copper, and lead ores. Cadmium is a soft, bluish-white metal which is
easily cut with a knife. It is similar in many respects to zinc. It
is a component of some of the lowest melting alloys; it is used
in bearing alloys with low coefficients of friction and great
resistance to fatigue; it is used extensively in electroplating,
which accounts for about 60% of its use. Cadmium is also used in many
types of solder, for standard E.M.F. cells, for Ni-Cd batteries,
and as a barrier to control atomic fission. The market for Ni-
Cd batteries is expected to grow significantly. Cadmium compounds
are used in black and white television phosphors and
in blue and green phosphors for color TV tubes. It forms a
number of salts, of which the sulfate is most common; the sulfide
is used as a yellow pigment. Cadmium and solutions of its
compounds are toxic. Failure to appreciate the toxic properties
of cadmium may cause workers to be unwittingly exposed
to dangerous fumes. Some silver solders, for example, contain
cadmium and should be handled with care. Serious toxicity
problems have been found from long-term exposure and work
with cadmium plating baths. Cadmium is present in certain
phosphate rocks. This has raised concerns that the long-term
use of certain phosphate fertilizers might pose a health hazard
from levels of cadmium that might enter the food chain. In
1927 the International Conference on Weights and Measures
redefined the meter in terms of the wavelength of the red cadmium
spectral line (i.e., 1 m = 1,553,164.13 wavelengths). This
definition has been changed (see under Krypton). The current
price of cadmium is about 50￠/g (99.5%). It is available in
high purity form for about $550/kg. Natural cadmium is made
of eight isotopes. Thirty-four other isotopes and isomers are
now known and recognized.
Uses
Different sources of media describe the Uses of 7440-43-9 differently. You can refer to the following data:
1. Batteries, including Ni-Cd storage batteries; coating and electroplating steel and cast iron; pigments; plastic stabilizers; constituent of low melting or easily fusible alloys, e.g., Lichtenberg's, Abel's, Lipowitz', Newton's, and Wood's metal; electronics and optics; soft solder and solder for aluminum; reactor control rods; hardener for copper; catalytsts.
2. A soft bluish metal, cadmium is extremely toxic, particularly in the compounds used for photography. It is found in zinc ores and in the mineral greenockite (CdS).
3. Cadmium is used in electroplating, in nickelcadmiumstorage batteries, as a coating forother metals, in bearing and low-meltingalloys, and as control rods in nuclear reactors.Cadmium compounds have numerousapplications, including dyeing and printingtextiles, as TV phosphors, as pigments andenamels, and in semiconductors and solarcells.Vegetables and cereals are the main sourcesof dietary Cd while meat and fish contain themetal to a lesser extent..
4. Cadmium alloyed with silver forms a type of solder with a low melting point. It is used tojoin electrical junctions and other specialized metallic components. Precautions are required since it is a toxic substance. (Note: This is not the same as common solder used to join metals,which is relatively safe.) Other cadmium alloys are used to manufacture long-wearing bearingsand as thin coatings for steel to prevent corrosion.Cadmium is a neutron absorber, making it useful as control rods in nuclear reactors. Therods are raised to activate the reactor and then lowered into the reactor to absorb neutronsthat halt the fission reaction.Cadmium, along with nickel, forms a nickel-cadmium alloy used to manufacture “nicadbatteries” that are shaped the same as regular small dry-cell batteries. .
5. cadmium is highly toxic elements. Cadmium can often be found in batteries.cadmium form the corresponding oxide when heated under oxygen. cadmium follow the general formula MX2 and are either insoluble (X=F) in water or show a low aqueous solubility.
Production Methods
Two major processes are used for producing cadmium: (1) pyro-hydro-metallurgical and (2) electrolytic. Zinc blende is roasted to eliminate sulfur and to produce a zinc oxide calcine. The latter is the starting material for both processes. In the pyro-hydro-metallurgical process, the zinc oxide calcine is mixed with coal, pelletized, and sintered. This procedure removes volatile elements such as lead, arsenic, and the desired cadmium. From 92 94% of the cadmium is removed in this manner, the vapors being condensed and collected in an electrostatic precipitator. The fumes are leached in H2SO4 to which iron sulfate is added to control the arsenic content. The slurry then is oxidized, normally with sodium chlorate, after which it is neutralized with zinc oxide and filtered. The cake goes to a lead smelter, while the filtrate is charged with highpurity zinc dust to form zinc sulfate or zinc carbonate and cadmium sponge. The latter is briquetted to remove excess H2O and melted under caustic to remove any zinc. The molten metal then is treated with zinc ammonium chloride to remove thallium, after which it is cast into various cadmium metal shapes. The process just described is known as the melting under caustic process. In a distillation process, regular rather than high-purity zinc is used to make the sponge. Then, after washing and centrifuging to remove excess H2O, the sponge is charged to a retort. The heating and distillation process is under a reducing atmosphere. Lead and zinc present in the vapors contaminate about the last 15% of the distillate. Thus, a redistillation is required. The cadmium vapors produced are collected and handled as previously described.
Definition
cadmium: Symbol Cd. A soft bluishmetal belonging to group 12 (formerlyIIB) of the periodic table; a.n.48; r.a.m. 112.41; r.d. 8.65; m.p.320.9°C; b.p. 765°C. The element’sname is derived from the ancientname for calamine, zinc carbonateZnCO3, and it is usually found associatedwith zinc ores, such as sphalerite(ZnS), but does occur as themineral greenockite (CdS). Cadmiumis usually produced as an associateproduct when zinc, copper, and leadores are reduced. Cadmium is used inlow-melting-point alloys to make solders,in Ni–Cd batteries, in bearingalloys, and in electroplating (over50%). Cadmium compounds are usedas phosphorescent coatings in TVtubes. Cadmium and its compoundsare extremely toxic at low concentrations;great care is essential wheresolders are used or where fumes areemitted. It has similar chemical propertiesto zinc but shows a greater tendencytowards complex formation.The element was discovered in 1817by F. Stromeyer.
General Description
Silver-white blue tinged lustrous metallic solid.
Air & Water Reactions
The finely divided metal is pyrophoric. Slowly oxidized by moist air to form CADMIUM oxide. Insoluble in water.
Reactivity Profile
A violent explosion occurred 30 minutes after placement of a CADMIUM rod into hydrazoic acid [Mellor 8 Supp. 2:50 1967]. Fused ammonium nitrate with powdered metal often produces a violent explosive reaction. Reactivity similar to zinc. May be incompatible with oxidants.
Hazard
Cadmium powder, dust, and fumes are all flammable and toxic if inhaled or ingested.Cadmium and many of its compounds are carcinogenic.Severe illness and death can occur from exposure to many cadmium compounds. It isabsorbed in the gastrointestinal tract. However, it can be eliminated in the urine and fecesin young, healthy people.
Health Hazard
There are several reports of cadmium poisoningand human death. Cadmium can enterthe body by inhalation of its dusts or fumes,or by ingestion. In humans the acute toxicsymptoms are nausea, vomiting, diarrhea,headache, abdominal pain, muscular ache,salivation, and shock. In addition, inhalationof its fumes or dusts can cause cough,tightness of chest, respiratory distress, congestionin lungs, and bronchopneumonia. A30-minute exposure to about 50 mg/m3 of itsfumes or dusts can be fatal to humans. Theoral LD50 value in rats is within the range of250 mg/kg.Cadmium is a poison that is accumulatedin the liver and kidneys. Thus, chronicpoisoning leads to liver and kidney damage.It is very slowly excreted. Its biologicalhalf-life in humans is estimated atabout 20–30 years (Manahan 1989). Cadmiumlevel in the kidney at 200 μg/g,can damage proximal tubules, resulting intheir inability to reabsorb small-moleculeproteins, such as β2-microglobulin (Luand Kacey 2003). Cigarette smoking andcalcium-deficient diet enhance its toxicity.Renal toxicity may occur in human subjectsas a result of chronic ingestion of low-leveldietary Cd. The absorption of this metal,however, through the GI tract is low. Cadmiumis also known to produce the so-calleditai-itai disease, which is a chronic renaldisease, producing bone deformity and kidneymalfunction. Cadmium, similar to otherheavy meals, binds to the sulfhydryl (-SH)groups in enzymes, thus inhibiting enzymaticacitivity. Intramuscular administrationof cadmium produced tumors in the lungs and blood in rats. There is sufficient evidenceof its carcinogenicity in animals.Data on accumulation of Cd in human kidneyand liver have been reviewed by Sataruget al. (2000). Epidemiological and autopsystudies have shown a relationship betweenthe tubular dysfunction and kidney Cd burden.A maximum tolerable level of kidneyCd has been suggested as 50 μg/g (wetweight) corresponding to a urinary excretionof 2 μg Cd per day. Safe daily levels of Cdintake in humans have been recommended tobe kept below 30 μg per day.
Fire Hazard
Flammable in powder form. Combustible.
Industrial uses
Cadmium (symbol Cd) is a silvery-white crystallinemetal that has a specific gravity of 8.6,is very ductile, and can be rolled or beaten intothin sheets. It resembles tin and gives the samecharacteristic cry when bent, but is harder thantin. A small addition of zinc makes it very brittle.It melts at 320°C and boils at 765°C. Cadmiumis employed as an alloying element insoft solders and in fusible alloys, for hardeningcopper, as a white corrosion-resistant platingmetal, and in its compounds for pigments andchemicals. It is also used for Ni–Cd batteriesand to shield against neutrons in atomic equipment;but gamma rays are emitted when theneutrons are absorbed, and these rays requirean additional shielding of lead.Most of the consumption of cadmium is forelectroplating. For a corrosion-resistant coatingfor iron or steel a cadmium plate of 0.008 mmis equal in effect to a zinc coat of 0.025 mm.The plated metal has a silvery-white color witha bluish tinge, is denser than zinc, and harderthan tin, but electroplated coatings are subjectto H2 embrittlement, and aircraft parts are usuallycoated by the vacuum process. Cadmiumplating is not normally used on copper or brasssince copper is electronegative to it, but whenthese metals are employed next to cadmium-plated steel a plate of cadmium may beused on the copper to lessen deterioration.
Safety Profile
Confirmed human
carcinogen with experimental carcinogenic,
tumorigenic, and neoplastigenic data. A
human poison by inhalation and possibly
other routes. Poison experimentally by
ingestion, inhalation, intraperitoneal,
Potential Exposure
Cadmium is a highly corrosion resistant and is used as a protective coating for iron, steel, and
copper; it is generally applied by electroplating, but hot
dipping and spraying are possible. Cadmium may be
alloyed with copper, nickel, gold, silver, bismuth, and aluminum to form easily fusible compounds. These alloys
may be used as coatings for other materials; welding electrodes, solders, etc. It is also utilized in electrodes of alkaline storage batteries, as a neutron absorber in nuclear
reactors, a stabilizer for polyvinyl chloride plastics, a deoxidizer in nickel plating; an amalgam in dentistry; in the
manufacture of fluorescent lamps, semiconductors,photocells, and jewelry, in process engraving, in the automobile and aircraft industries; and to charge Jones
reductors. Various cadmium compounds find use as fungicides, insecticides, nematocides, polymerization catalysts,
pigments, paints, and glass; they are used in the photographic industry and in glazes. Cadmium is also a contaminant of superphosphate fertilizers. Human exposure to
cadmium and certain cadmium compounds occurs through
inhalation and ingestion. The entire population is exposed
to low levels of cadmium in the diet because of the entry
of cadmium into the food chain as a result of its natural
occurrence. Tobacco smokers are exposed to an estimated
17 μg/cigarette. Cadmium is present in relatively low
amounts in the earth’s crust; as a component of zinc ores,
cadmium may be released into the environment around
smelters
Carcinogenicity
Cadmium and cadmium compounds are known to be human carcinogens based on sufficient evidence of carcinogenicity from studies in humans, including epidemiological and mechanistic studies. Cadmium and cadmium compounds were first listed as reasonably anticipated to be human carcinogens in the First Annual Report on Carcinogens in 1980, based on sufficient evidence of carcinogenicity from studies in experimental animals. The listing was revised to known to be human carcinogens in the Ninth Report on Carcinogens in 2000.
Environmental Fate
Cadmium inhibits plasma membrane calcium channels and
Ca2t-ATPases. It also inhibits repair of DNA damaged by
various chemicals, an effect which is believed to be associated
with the induction of tumors. Although cadmium forms
a metallothionein, the preformed cadmium metallothionein is
nephrotoxic (toxic to the kidneys); it is suggested that effects
occur when, at some stage in the kidney, the cadmium is
dissociated from the metallothionein. In Itai-Itai disease (see
Human under Chronic Toxicity section), patients were found
to have chromosome abnormalities.
Cadmium has an affinity for sulfhydryl groups, and hence
can inhibit enzymes; however, cells treated with cadmium
showed proliferation of peroxisomes, which contain catalase,
an enzyme. It appears that cadmium at first inhibits catalase
activity and then, after a time, enhances that activity. In addition,
cadmium inhibits enzymes involved in gluconeogenesis
(the generation of glycogen for energy production from noncarbohydrate
precursors). It also inhibits oxidative phosphorylation
(energy production) and depresses trypsin inhibitor
capacity.
storage
Cadmium should be kept stored in a tightly closed container in a cool place. It should be
kept stored in a separate locked safety storage cabinet
Purification Methods
Any oxide contaminant is removed by filtering the molten metal, under vacuum, through quartz wool. Its solubility in Hg is 5.2% (18o), and it is soluble in mineral acids. [Wagenknecht & Juza in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol II p 1092 1965.]
Toxicity evaluation
As indicated in the Exposure and Exposure Monitoring section,
cadmium is widely distributed in the environment from
a variety of natural and anthropogenic sources. Cadmium
emitted into the air is often found bound to small particulates
and can travel with these particulates over long distances. As
a result, cadmium can remain in the atmosphere for long
periods of time until it is deposited by gravitational settling or
in rain and snow. Cadmium tends to be more mobile in water
than other heavy metals although it will complex with humic
substances and can precipitate out under certain conditions.
Cadmium can bioaccumulate in aquatic organisms; the degree
of accumulation is associated with the pH and humic content
of the water. It can also bioaccumulate in plants and in the
animals that feed on these plants; for example, cattle and
wildlife. However, terrestrial bioaccumulation is much lower
than that in water and cadmium concentrations at the top of
the terrestrial food chain are not much higher than those at the
lower end of the chain.
Incompatibilities
Air exposure with cadmium powder may
cause self-ignition. Moist air slowly oxidizes cadmium
forming cadmium oxide. Cadmium dust is incompatible
with strong oxidizers, ammonium nitrate; elemental sulfur;
hydrazoic acid; selenium, zinc, tellurium. Contact with
acids cause a violent reaction, forming flammable hydrogen
gas.
Waste Disposal
With cadmium compounds in
general, precipitation from solution as sulfides, drying and
return of the material to suppliers for recovery is recommended. Cadmium may be recovered from battery scrap as
an alternative to disposal. In accordance with
40CFR165, follow recommendations for the disposal of
pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting
your local or federal environmental control agency, or by
contacting your regional EPA office.
Precautions
On exposures to cadmium, wash the skin immediately with plenty of water and a nonabrasive soap. Workers should cover the exposed skin with an emollient.
Check Digit Verification of cas no
The CAS Registry Mumber 7440-43-9 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,4,4 and 0 respectively; the second part has 2 digits, 4 and 3 respectively.
Calculate Digit Verification of CAS Registry Number 7440-43:
(6*7)+(5*4)+(4*4)+(3*0)+(2*4)+(1*3)=89
89 % 10 = 9
So 7440-43-9 is a valid CAS Registry Number.
InChI:InChI=1/Cd/q+2
7440-43-9Relevant articles and documents
Synthesis and characterisation of zinc gallyl complexes: First structural elucidations of Zn-Ga bonds
Jones, Cameron,Rose, Richard P.,Stasch, Andreas
, p. 2997 - 2999 (2007)
Reactions of the anionic gallium(i) heterocycle, [:Ga{[N(Ar)C(H)] 2}]- (Ar = C6H3Pri 2-2,6), with two N,N-chelated zinc chloride complexes have yielded the compounds, [{Pri2
Synthesis, characterization and photoelectrochemical properties of poly(3,4-dioctyloxythiophene)-CdS hybrid electrodes
Refczynska, Monika,Mieczkowski, Józef,Skompska, Magdalena
, p. 2984 - 2993 (2008)
CdS-poly(3,4-dioctyloxythiophene) (CdS-PDOT) hybrid electrode has been prepared by electrosynthesis of PDOT on Au substrate followed by electrodeposition of Cd and its chemical transformation into CdS. The polymer and semiconductor obtained by this method form hemispherical structures dispersed on the substrate. The synthesized composites were characterized by UV-vis absorption spectra and energy dispersive X-ray spectra (EDS). The AFM images of the electrodes covered with different amounts of each component were correlated with photoactivity of the hybrid electrodes. Photoresponses of Au/PDOT-CdS electrodes under illumination in aqueous solution of Na2S were also compared with those of CdS without polymer. Enhancement of the photocurrent achieved for some polymer-to-semiconductor ratio is discussed in terms of the hybrid electrode morphology and hole-mediating properties of PDOT. The power conversion efficiency of the device based on CdS-PDOT hybrid electrode was determined from photocurrent-potential behavior of two electrode system, Au/CdS-PDOT/0.1 M Na2S/Pt with a variable resistance in series in the external circuit.
Denham
, p. 556 - 556 (1919)
Electrodeposition of cadmium from a sulfate electrolyte in the presence of a fixative
Medvedev,Makrushin
, p. 62 - 64 (2010)
Electrodeposition of cadmium from a sulfate electrolyte containing CdSO4 · 8/3H2O, H2SO4, and a fixative was studied.
Qian, Y.-T.,Kershaw, R.,Soled, S.,Dwight, K.,Wold, A.
, p. 211 - 216 (1984)
Yntema, L. F.,Audrieth, L. F.
, p. 2693 - 2698 (1930)
Radiation Electrochemistry of the Colloidal Cadmium Microelectrode. Catalysis of Hydrogen Formation by Organic Free Radicals
Henglein, A.,Lilie, J.
, p. 1246 - 1251 (1981)
Cadmium sols with a mean particle size of 11 nm or less were obtained in the radiolytic reduction of Cd2+ ions in the presence of 1E-4 - 1E-3 base-M sodium polyvinyl sulfate.These sols which contained small concentrations of residual Cd2+ were found to catalyze the formation of hydrogen by 1-hydroxy-1-methylethyl radicals, (CH3)2COH, as efficiently as the sols of the previously studied noble metals.The organic radicals transfer electrons to the colloidal particles at a practically diffusion-controlled rate.The cathodically charged colloidal particles first reduce and deposit residual cadmium ions and then store excess electrons.Both the stored electrons and the deposited cadmium atoms are able to produce H2 from water.The reduction of water by deposited cadmium atoms is explained by a two-step mechanism: (1) dissolution of an atom as Cd2+ to leave negative charges on the colloidal particle and (2) transfer of these charges to water.The mechanism of catalysis is also described in terms of an equivalent electrical circuit, in which the colloidal microelectrode appears as a capacitance for the storage of reduction equivalents.A 3E-4 M cadmium solution (containing ca. 3E-5 M residual Cd2+ ions) was found to have a capacity of 0.98 F/L for the storage of excess electrons.
Synthesis, structural characterization, and spectroscopy of the cadmium-cadmium bonded molecular species Ar′CdCdAr′ (Ar′ = C6H3-2,6-(C6H3-2,6-Pr i2)2)
Zhu, Zhongliang,Fischer, Roland C.,Fettinger, James C.,Rivard, Eric,Brynda, Marcin,Power, Philip P.
, p. 15068 - 15069 (2006)
The synthesis and first structural characterization of a cadmium-cadmium bonded molecular compound Ar-CdCdAr- (Ar- = C6H3-2,6-(C6H3-2,6-Pri2)2) are reported. The existence of the Cd-Cd bond was established by 113Cd NMR spectroscopy and X-ray diffraction (Cd-Cd = 2.6257(5) A). Like its group 12 analogue Ar-ZnZnAr-, DFT calculations showed that Ar-CdCdAr- had significant p-character in the Cd-Cd σ-bonding HOMO. Copyright
House, J. E. Jr.,Marquardt, Lois A.
, p. 277 - 282 (1989)
∞1[M(μ-O2C-C6H 4-CO2)(NH3)2] (M = Cu, Cd; O 2C-C6H4-CO2 = benzene-1,4- dicarboxylate, terephthalate): ID coordination polymers with strong inter-chain hydrogen bonding
Paul, Barbara,Zimmermann, Boris,Fromm, Katharina M.,Janiak, Christoph
, p. 1650 - 1654 (2004)
Compounds ∞1[M(μ-O2C-C 6H4-CO2)(NH3)2] crystallize as straight- (M = Cu) and kinked-chain (M = Cd) coordination polymers through the bridging action of the bis-mono (Cu) and bisbidentate (Cd) benzene-1,4-dicarboxylate (terephthalate) ligand. N-H...O hydrogen bonding connects the chains to a three-dimensional supramolecular network. Thermogravimetry shows the compounds to be stable up to 255°C (M = Cu) and 70°C (M = Cd) where decomposition starts with the loss of one ammin ligand. ∞1[(Cd(μ-O2C-C6H 4-CO2)(NH3)2] exhibits a luminescence with λem,max = 392 nm (λex = 240 nm) on the same order of magnitude as Na2(O2C-C 6H4-CO2).
ENHANCED MASS TRANSPORT IN ELECTROGALVANIZING SYSTEMS BY HYDROGEN EVOLUTION.
Chen,O'Keefe
, p. 789 - 794 (1988)
The effect of hydrogen evolution on mass transport during electrogalvanizing was evaluated for a vertical electrode by using a electrochemical tracer. The potentiodynamically measured limiting current of a petroleum tracer was compared with those obtained by the codeposition method at various current densities. The effects of pH on the hydrogen evolution and the mass transfer rate during electrogalvanizing were also determined. The Sherwood number was calculated and compared with that predicted by natural convection. It has been found that the mass transport was mainly enhanced by natural convection at current densities less than 25 mA cm** minus **2 and by simultaneous hydrogen evolution at relatively higher current densities.
Kinetics and mechanism of free-surface vaporization of zinc, cadmium and mercury oxides analyzed by the third-law method
L'vov, Boris V.,Ugolkov, Valery L.,Grekov, Fedor F.
, p. 187 - 193 (2004)
On the basis of critical comparison of experimental and theoretical values of the E parameter and investigation of the retardation effect of oxygen on the evaporation rate of ZnO, CdO and HgO, it was concluded that the dissociative evaporation of ZnO and HgO proceeds with releasing of atomic oxygen (O) as a primary product of decomposition. By contrast, the mechanism of dissociative evaporation of CdO corresponds to the equilibrium reaction with releasing of molecular oxygen (O2) as a primary product of decomposition. As was shown, this difference in mechanisms is not related with interatomic O-O distances in these oxides. From the analysis of crystal structure for 12 different oxides, which evaporate with releasing of atomic oxygen, and for 13 compounds, which evaporate with releasing of molecular oxygen, it was revealed that the first mechanism is observed for all oxides with the cubic crystal structure. It was proposed that a decisive role in this difference belongs to a local symmetry in the position of O atoms.
A new binuclear Cd(II)-containing ionic liquid: Preparation and electrocatalytic activities
Zhuang, RuiRui,Jian, FangFang,Wang, KeFei
, p. 3614 - 3618 (2009)
The present work reports on the synthesis, characterization and performance of a new metal-containing ionic liquid [(C10H21)2-bim]2[Cd2Cl6] (bim = benzimidazole) as an electrocatalyst of hy
Fabrication of metal cadmium nanowires by an assistant thermal decomposition method
Zhao, Jian-Wei,Ye, Chang-Hui,Fang, Xiao-Sheng,Yan, Peng,Zhang, Li-De
, p. 1482 - 1483 (2005)
Using a simple assistant thermal decomposition method, metal cadmium nanowires were large-scale fabricated from CdS powders in an argon atmosphere. Investigation results demonstrate that the Cd nanowires have lengths of several microns and diameter of about 70-150 nm. Copyright
Metal azelate coordination polymers containing a kinked dipyridyl tether: CdSO4 topology and "ligand vacancy" primitive cubic three-dimensional networks
Shyu, Eric,Krishnan, Subhashree Mallika,Supkowski, Ronald M.,LaDuca, Robert L.
, p. 1437 - 1446 (2009)
Hydrothermal self-assembly has generated three coordination polymers incorporating the kinked hydrogen-bonding capable tethering ligand 4,4′-dipyridylamine (dpa) and the long flexible aliphatic dicarboxylate azelate dianion (-O2C(CH
ON THE MECHANISM OF GROWTH OF CdTe BY ORGANOMETALLIC VAPOR-PHASE EPITAXY.
Bhat,Taskar,Ghandhi
, p. 195 - 198 (1987)
In this paper are presented some experimental results to explain mechanisms involved in the growth of CdTe by organometallic vapor-phase epitaxy (OMVPE). A pyrolysis study of dimethylcadmium (DMCd) was conducted in an OMVPE reactor, in the temperature range 230 degree -400 degree C. It was found that dimethylcadmium decomposes above approximately 230 degree C and the reaction is heterogeneous from 230 degree to 370 degree C. CdTe growth was also studied over a range of temperature from 300 degree to 375 degree C and for various reactor parameters. In all cases, the CdTe deposition rate was found to be closely related to the decomposition of dimethylcadmium.
Precursor synthesis and magnetic properties of Cd1?xFexO (0 ? x ? 0.07)
Krasil'nikov, Vladimir N.,Dyachkova, Tatyana V.,Tyutyunnik, Alexander P.,Gyrdasova, Olga I.,Perevozchikova, Yuliya A.,Marchenkov, Vyacheslav V.,Weber, Harald W.
, p. 456 - 458 (2017)
The polycrystalline solid solutions Cd1 – xFexO (0 ? x ? 0.07) possessing ferromagnetic properties at 5 K and room temperature have been synthesized by a precursor method using the formate Cd1 – xFex(HCOO)2 ·2H2O.
Underpotential deposition of cadmium adatoms on Te and CdTe
Osipovich,Poznyak
, p. 996 - 1002 (2006)
Underpotential deposition (UPD) of Cd adatoms onto the surface of Te and CdTe films in Cd2+-containing solutions has been studied using electrochemical methods and AFM. The electrochemical deposition of Cd adatoms on Te and CdTe begins at potentials 400 mV more positive than the reversible potential of Cd2+/Cd couple and proceeds irreversibly. A strong chemical interaction of Cd adatoms with the surface Te atoms is the driving force of the UPD process. The deposition of Cd adatoms on the tellurium surface is accompanied by their stepwise interaction with tellurium to give CdTe nanophase.
Multipulse electrochemical/chemical synthesis of CdS/S core/shell nanocrystals exhibiting ultranarrow photoluminescence emission lines
Gorer,Penner
, p. 5750 - 5753 (1999)
Ensembles of sulfur capped, cadmium sulfide nanocrystals (CdS/S NCs) which exhibit photoluminescence (PL) emission line widths of 15-35 meV at 20 K have been obtained. These CdS/S NCs were synthesized using a new variant of the electrochemical/chemical (E/C) method: Cadmium (Cd°) NCs were first electrodeposited from an aqueous Cd2+ plating solution using a train of 8-10 ms plating pulses separated by ≈1.0 s mixing segments at the open circuit potential. These Cd° nanoparticles were then oxidized to Cd-(OH)2, and CdS/S NCs were obtained by exposure of Cd(OH)2 nanoparticles to H2S at 300°C. Ensembles of 200 000-400 000 CdS/S NCs prepared using this multipulse technique exhibited PL emission lines narrower than 35 meV. CdS/S NCs were also synthesized using the same E/C method except that a single Cd° plating pulse was employed, and these CdS/S NCs exhibited PL emission line widths of 125-180 meV. TEM analysis of Cd(OH)2 precursor particles confirms that the narrower lines obtained using multipulse Cd° electrodeposition result from improved size monodispersity of the CdS core, which is attributed to the diffusional decoupling of Cd° nanoparticles during growth.
METALLAVIOLENES. AN ESR STUDY
Kaim, Wolfgang
, p. 157 - 170 (1983)
The preparation and ESR-spectroscopic characterization of radical complexes cation radical with L=4,4'-bipyridine is described, where MRn=BePh, MgPh, ZnPh, -BEt3, GaMe2, InMe2 and SiMe3.While the bis(trimethylsilyl) derivative could be obtained via one-electron oxidation of the corresponding 4,4'-(1H, 1'H)-bipyridinylidene, the other complexes were prepared by the reaction of 4,4'-bipyridine with potassium and the organometal MRn+1 or the halide XMRn in THF.Use of organo-cadmium or -thallium compounds in such a procedure leads to deposition of the metals.The Grignard reagents MgPh2 and BrMgPh reduce 4,4'-bipyridine in an electron transfer process to yield an unsymmetrical complex.The new organometallic 4,4'-bipyridinium ( violene ) radical complexes can be incorporated into a series of related radicals which exhibits the sensitivity of the unpaired electron distribution towards metal coordination.
Preparation, characterization and catalytic behavior of CdFe 2O4 and Cd nanocrystals on AP, HTPB and composite solid propellants, Part: 79
Singh,Kapoor,Dubey, Reena,Srivastava, Pratibha
, p. 112 - 118 (2010)
CdFe2O4 and Cd nanocrystals were synthesized by wet chemical and hydrazine reduction methods, respectively. These nanocrystals were characterized by XRD and TEM. Their catalytic activity was investigated on the thermal decomposition
Cadmium electroextraction from alkali oxide melts
Barbin,Kazantsev,Vatolin
, p. 576 - 579 (2005)
A method is proposed for cadmium electroextraction from alkali oxide melts, suitable for CdO-containing waste processing. A bench-top electrolyzer design is described, and the process parameters are optimized.
Harrison, J. A.,Sandbach, D. R.,Stronach, P. J.
, p. 179 - 190 (1979)
Kersten, H.
, p. 649 - 653 (1931)
Synthesis, dft calculations, antiproliferative, bactericidal activity and molecular docking of novel mixed-ligand salen/8-hydroxyquinoline metal complexes
Abdalla, Ehab M.,Abdel Rahman, Laila H.,Al-Farhan, Badriah Saad,Basha, Maram T.,El-Ezz, Doaa Abou,El-Saghier, Ahmed M. M.,Marzouk, Adel A.,Shehata, Mohamed R.
, (2021/08/13)
Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive agents, their metal complexes are still under development. Here, we report the synthesis of novel mixed-ligand metal complexes (MSQ) comprising salen (S), derived from (2,2′-{1,2-ethanediylbis [nitrilo(E) methylylidene]}diphenol, and 8-hydroxyquinoline (Q) with Co(II), Ni(II), Cd(II), Al(III), and La(III). The structures and properties of these MSQ metal complexes were investigated using molar conductivity, melting point, FTIR,1H NMR,13C NMR, UV–VIS, mass spectra, and thermal analysis. Quantum calculation, analytical, and experimental measurements seem to suggest the proposed structure of the compounds and its uncommon monobasic tridentate binding mode of salen via phenolic oxygen, azomethine group, and the NH group. The general molecular formula of MSQ metal complexes is [M(S)(Q)(H2O)] for M (II) = Co, Ni, and Cd or [M(S)(Q)(Cl)] and [M(S)(Q)(H2O)]Cl for M(III) = La and Al, respectively. Importantly, all prepared metal complexes were evaluated for their antimicrobial and anticancer activities. The metal complexes exhibited high cytotoxic potency against human breast cancer (MDA-MB231) and liver cancer (Hep-G2) cell lines. Among all MSQ metal complexes, CoSQ and LaSQ produced IC50 values (1.49 and 1.95 μM, respectively) that were comparable to that of cisplatin (1.55 μM) against Hep-G2 cells, whereas CdSQ and LaSQ had best potency against MDA-MB231 with IC50 values of 1.95 and 1.43 μM, respectively. Furthermore, the metal complexes exhibited significant antimicrobial activities against a wide spectrum of both Gram-positive and-negative bacterial and fungal strains. The antibacterial and antifungal efficacies for the MSQ metal complexes, the free S and Q ligands, and the standard drugs gentamycin and ketoconazole decreased in the order AlSQ > LaSQ > CdSQ > gentamycin > NiSQ > CoSQ > Q > S for antibacterial activity, and for antifungal activity followed the trend of LaSQ > AlSQ > CdSQ > ketoconazole > NiSQ > CoSQ > Q > S. Molecular docking studies were performed to investigate the binding of the synthesized compounds with breast cancer oxidoreductase (PDB ID: 3HB5). According to the data obtained, the most probable coordination geometry is octahedral for all the metal complexes. The molecular and electronic structures of the metal complexes were optimized theoretically, and their quantum chemical parameters were calculated. PXRD results for the Cd(II) and La(III) metal complexes indicated that they were crystalline in nature.
Anti-hepatocellular carcinoma, antioxidant, anti-inflammation and antimicrobial investigation of some novel first and second transition metal complexes
Hassan, Safaa S.,Khalf-Alla, Perihan A.
, (2020/02/05)
New coordination compounds of some selected metal ions from the first and second transition metals series with a Schiff base were synthesized and characterized. The Schiff base is derived from 4-Aminoantipyrine and 3-(hydroxyimino) butan-2-one. The compounds were characterized by different analysis tools like; elemental analysis, mass spectra, Fourier transform infrared (FTIR) as well as electronic spectra, magnetic measurements, molar conductance and thermal analysis technique. All complexes were formed with 1:1 (metal: ligand) stoichiometry except Mn (II) where 1:2 (Mn: ligand) is formed. Schiff base ligand interacted as a tridentate ligand by using the nitrogen atoms of the imine and the oximato groups and the carbonyl oxygen atom as donor groups with all studied metal ions except copper (II) and manganese (II) where the carbonyl oxygen is not shared in the coordination. These complexes show various physicochemical properties. X-ray powder diffraction shows different crystal systems; Cd (II) complex: hexagonal, Cu (II) complex: orthorhombic; and [Ni (II), Mn (II), Rh (III) & Pd (II)] complexes: monoclinic. All compounds showed potent cytotoxicity against the growth of human liver cancer cell lines. The square planar Pd (II) complex was more active than those of octahedral geometries of all other synthesized complexes. Cd (II) complex has the highest microbial growth inhibition than the rest of the prepared complexes. The docking active sites interactions were evaluated using the selected proteins EGFR tyrosine kinase and protein crystal structure of GlcN-O-P synthase. in vitro antioxidant assay revealed potent free radical scavenging activity of the three synthesized Cu (II), Pd (II) and Rh (III) complexes that exceeded the standard ascorbic acid. Pd (II) complex shows the most significant inhibition denaturation percent.
![6Hg(2+)*4As(2-)*CdBr6(4-)=[Hg6As4][CdBr6]](http://file1.lookchem.com/cas/reactions/2021/08/20/16684518.svg+xml_ms)
![6Hg(2+)*4Sb(2-)*CdI6(4-)*0.6Hg=[Hg6Sb4][CdI6]Hg0.6](http://file1.lookchem.com/cas/reactions/2021/08/20/18017943.svg+xml_ms)
2]](http://file1.lookchem.com/cas/reactions/2021/08/20/18147823.svg+xml_ms)
![[Cd(C5H3N(C(CH3)NC6H4NSO2C6H4CH3)2)(H2O)]*H2O](http://file1.lookchem.com/cas/reactions/2021/08/20/17764806.svg+xml_ms)
