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Journal of Inorganic Biochemistry
Volume 100, Issue 9,
September 2006
, Pages 1462-1469
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Abstract
The reaction of chromium(III) chloride, salicylic acid (SA) and ethylenediamine (en) led to the formation of chromium complex [Cr(SA)(en)2]Cl·2H2O(1). The crystal structure belongs to monoclinic system with the space group P2(1), R1=0.0358. In this compound, Cr(III) atom is six-coordinated in octahedral coordination geometry by one phenolic hydroxyl oxygen, one carboxylate oxygen from the salicylic acid and four nitrogen atoms from two ethylenediamine molecules, respectively. The transfer manners of Cr(III) from the title compound to the low-molecular-mass chelator, ethylenediamine-N,N,N′,N′-tetraacetic acid (EDTA) and the iron-binding protein apoovotransferrin (apoOTf) were followed by a combination of UV–visible (UV–Vis) and fluorescence spectra in 0.01M Hepes at pH 7.4. The results show that Cr(III) can be transferred from the complex to apoovotransferrin with the retention of the salicylate acted as a synergistic anion.
Introduction
In the last 15 years, nutritional studies have suggested that chromium(III) may have an essential role in mammals. Chromium is known to activate enzymes, maintain protein stability and enhance carbohydrate metabolism [1], [2], [3], [4], [5]. Chromium(III) picolinate, Cr(pic)3, has been the most thoroughly studied of these synthetic products and has become a very popular nutritional supplement [6]. However, the effect of Cr(pic)3 has been extremely contentious. Of particular concern are recent reports that the complex can efficiently cleave DNA in the presence of biological reducing agents and can induce strand breaks in chromosomes of intact cells [7], [8], [9], [10]. Hence, a search has been underway to identify the biologically active form of chromium, that is, the biomolecule that binds chromium(III) and possesses an intrinsic function associated with insulin action in mammals [11], [12].
Up to date, the mechanisms of absorption of chromic ions are uncertain. Little is known of the fate of Cr(III) intaken orally. Essentially no data exist on the forms of chromium(III) in food as a result of its very low concentration [13]. The fate of chromium(III) once it enters the bloodstream is better elucidated. The iron-transport protein transferrin has been proposed to serve as the major chromium transport agent [6]. Vincent has studied the interaction of Cr(pic)3 with transferrin by UV–Vis spectrum [14], [15]. In order to explore the mechanism of chromium(III) absorption, one novel chromium(III) complex [Cr(SA)(en)2]Cl·2H2O was synthesized, and then the manner, in which chromium is transferred from the complex to apoovotransferrin (apoOTf), was followed by a combination of UV–visible (UV–Vis) and fluorescence spectra. As a control experiment, EDTA was employed first as a simple competition agent at different temperature. The ligand salicylic acid was chosen originally because of its low toxicity and the similar structure with that of aspirin.
Section snippets
Materials and physical measurements
All manipulations were performed under aerobic conditions, and all chemicals were all analytical grade reagents and were used without further purification. Apoovotransferrin was obtained from Sigma (Lot 115H7080). Deionized water was used throughout. All glassware, including absorption and fluorescence cuvettes (1×1cm), were routinely soaked in 1M HNO3 and then rinsed with deionized water.
UV–visible (UV–Vis) spectra were measured with a HP8453 UV–Vis spectrophotometer. Fluorescence spectra were
Description of the structure of [Cr(SA)(en)2]Cl·2H2O
The structure of [Cr(SA)(en)2]Cl·2H2O was determined by X-ray crystallography. The perspective structure and the atomic numbering schemes for the chromium complex are shown in Fig. 1. Selected bond lengths and angles are given in Table 2.
The main structure of the title compound is made up of one [Cr(SA)(en)2]+ complex cation, one Cl− and two water solvate molecules. The chromium(III) center is a octahedron with four nitrogen atoms (Cr–N, 2.064–2.095Å) from two en molecules, one phenolic
Conclusions
This paper describes the synthesis and characterization of the complex [Cr(SA)(en)2]Cl·2H2O and the reaction with apoovotransferrin. The mechanisms of transfer of chromium from the complex to EDTA and apoOTf are different. Competition studies show that Cr(III) can be transferred from the complex to apoovotransferrin, with the retention of the salicylate, it is inferred first by the author that a very stable ternary complex salicylate–Cr(III)–transferrin was formed. The use of salicylic acid is
Abbreviations
- Hepes
N-2-hydroxyethyl-piperazine-N′-2-ethansulfonic acid
- EDTA
ethylenediamine-N,N,N′,N′-tetraacetic acid
- apoOTf
apoovotransferrin
- SA
salicylic acid
- en
ethylenediamine
Supplementary materials
Crystallographic data for the compound has been deposited with the Cambridge Crystallographic Data Centre, CCDC Nos. 289525. Copies of this information may be obtained free of charge from The Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK, fax: +44 1223 336 033, e-mail: [emailprotected] or http://www.ccdc.cam.ac.uk.
Acknowledgements
This work was supported by the National Natural Science Foundation of PR China (No. 20371031) and the Natural Science Foundation of Shanxi Province (No. 20031017).
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Cited by (20)
A couple of antitumor Pd(II) complexes make DNA-refolding and HSA-unfolding: Experimental and docking studies
2022, Journal of Molecular Liquids
Citation Excerpt :
1H NMR (250 MHz, DMSO‑d6, ppm, s = singlet, sb = singlet broad, d = doublet, t = triplet, m = multiplet); 1.64-(sb, 2H, Ha), 2.84-(s, 4H, Hb), 4.36-(m, 4H, Hc), 6.75-(m, 1H, Hg), 6.91-(d, 1H, Hh), 7.35-(m, 1H, Hi), 8.81-ppm (d, 1H, Hj) [43–45] (Fig. 1). Electronic absorption spectrum of complex in water exhibit three bands at 215-(logε = 4.20), 240-(logε = 4.30) and 310-nm (logε = 3.96) which may be assigned to intraligand n → σ*, π → π* and n → π* transitions of propylenediamine and salicylate ligands [46–48]. Sulfosalicylic acid was converted here to its tri-sodium salt and [Pd(pn)Cl2] to [Pd(pn)(H2O)](NO3)2 as defined in the [Pd(pn)(SA)] procedure above.
Two novel Pd(II) complexes, [Pd(pn)(SA)] (I) and [Pd(pn)(SSA)] (II)) pn=propylenediamine, SA=salicylate and SSA=sulfosalicylate (were made and characterized by spectroscopic techniques (UV–Vis, FT-IR and 1H NMR), elemental analysis (CHNS) and molar conductivity measurements. They are Pd(II) analogs of the well-known anticancer drugs viz carboplatin and oxaliplatin, where two cis donor atoms are nitrogen and the other two are oxygen in a near square planar array. In-vitro antitumor activity of these compounds against K562 cancer cell line were evaluated via MTT assay and showed promising activities. Their interaction with calf thymus DNA (CT-DNA) and human serum albumin (HSA) was assessed by electronic absorption, fluorescence, gel electrophoresis and circular dichroism techniques. For both biomolecules, the fluorescence quenching occurs through static procedure. CT-DNA- and HSA-binding affinities of the complexes is in the order of (I) < (II) and they effectively interact with these biomolecules at very low concentrations. The negative sign of ΔS° and ΔH° calculated from the fluorescence studies indicated that van der Waals and hydrogen-bond forces hold the complexes in the grooves of CT-DNA and or possibly in the main binding pocket of HSA. In-silico molecular docking calculation revealed the minor groove binding of both complexes with DNA and supported the higher binding affinity of complex (II) towards DNA. It also confirmed the insertion of both complexes in the site I of HSA.
Chromium(III) complexes
2021, Comprehensive Coordination Chemistry III
During the period of 2003–19, the chemistry of trivalent chromium has garnered significant research effort, gathering over 1100 publications on the matter. This research is driven predominantly by interest in catalytic transformations, molecular magnetism, and novel stoichiometric reactivity. CrIII complexes are overwhelmingly dominated by octahedral environments, with some rare instances of this ion displaying seven-, five-, four-, three-, and two-coordinate geometries. Consequently, forcing CrIII to adopt differential coordination numbers often results in interesting coordination chemistry, such as the isolation of rare CrIII-CO complexes, which are typically only observed in low-valent Cr chemistry. The vast majority of ligands coordinating to CrIII are bound through 1–4 donor atoms (denoted η1–η4 here), though examples of ligands with 5, 6, 7, and 10 donor atoms have been reported as well (η5, η6, η7, and η10).
Probing Cr(III) from Cr(pic)<inf>3</inf> derivatives in living cell by two rhodamine B-based AIEgens
2021, Inorganic Chemistry Communications
Citation Excerpt :
Even some research figured out that Cr(pic)3 is probable to enter the cell and eliminate from the body in the intact form [23], which reduces the bioavailability of Cr(pic)3 incredibly [24,25]. Therefore, many researchers tried to improve the bioavailability of Cr(III) supplements by employing ligands with lower coordination ability than picolinate [26–28]. However, whether Cr(pic)3 release Cr(III) in the organism is still unknown, and factors affecting bioavailability of Cr(III) supplements is ambiguous.
Two rhodamine B-based compounds 1 and 2 were prepared for application of fluorescence Cr(III) probes, and they inherit aggregation induced emission (AIE) features with strong red emission in water. Fluorescence spectra and cell imaging proved that compounds 1 and 2 were highly responsive to Cr(III), and they were employed to investigate the decomposition of chromium picolinate (Cr(pic)3) in the living cells. As a result, Cr(III) was captured by compound 1 and 2 from Cr(pic)3 in living cell. This result demonstrated that the biological mechanism of Cr(pic)3 could be explored by the fluorescent tracer.
Achieving highly sensitive detection of Cu<sup>2+</sup> based on AIE and FRET strategy in aqueous solution
2019, Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
Citation Excerpt :
Moreover, AIE features of 1 at different pH (7.0–14.0) were further investigated by fluorescent spectroscopy. As shown in Fig. 2b, the FI gradually decreased with the increasement of pH, and enormous blue shift was observed from 525 nm to 471 nm at pH 13 (inset), the molecule is less fluorescent at high pH. According to literature, pKa of –OH on salicylic acid group was 13.40 [35]. At high pH solution, phenolic hydroxyl group will be deprotonated and the intramolecular N⋯HO hydrogen bonds must be destroyed.
(Video) tetraamine Copper Sulfate crystals preparationThe aggregation-induced emission (AIE) luminogens are now showing strong potential in mimicking the energy donor of fluorescence resonance energy transfer (FRET) system. Herein, one highly efficient FRET system 1-NiR is successfully fabricated in aqueous solution based on an AIE active compound 1 and fluorescence dyes (Nile red (NiR)). 1 acts as the energy donor and NiR acts as the acceptor in the FRET system with the optimum concentrations ratio [1]/[NiR] = 100. Besides, the AIE(1) itself displays excellent selectivity for Cu2+ ions at 525 nm with the detection limit of 1.32 × 10−7 M. While through the FRET system of 1-NiR system, the detection limit of Cu2+ can be further decreased to 9.12 nM by monitoring the fluorescence at 630 nm. As a result, using an AIE probe to detect Cu2+ based on FRET mechanism is a promising strategy.
Refolding and unfolding of CT-DNA by newly designed Pd(II) complexes. Their synthesis, characterization and antitumor effects
2017, International Journal of Biological Macromolecules
Citation Excerpt :
UV–Vis spectra of the complexes (1) and (2) showed four bands at 310-(log ε = 4.19), 245-(log ε = 4.29), 210-(log ε = 4.14) and 200-nm(log ε = 4.01) for (1) and at 310-(log ε = 4.28), 250-(log ε = 4.27), 215-(log ε = 4.16) and 200-nm(log ε = 3.99) for (2). These bands are tentatively assigned to intraligand π → π* and n → π* transitions of 2,2′-bipyridine, salicylate and sulfosalicylate ligands [38–41]. The IR spectra of the mentioned complexes are recorded in the range 400–4000 cm−1 as KBr pellets.
New antitumor Pd(II) compounds derived from oxygen donor ligands salicylate (SA) (1) and sulfosalicylate (SSA) (2) dianions and nitrogen donor heterocyclic ligand 2,2′-bipyridine (bpy) were synthesized and characterized by elemental analysis, UV–Vis, FT-IR, 1H NMR and conductivity measurements. The complexes evaluated for their cytotoxicity effects towards cancer cell line of K562 using MTT assay. They are more cytotoxic than cisplatin. The dependence of their interaction modes with CT-DNA on concentration of the compounds has been discovered in this work. CT-DNA binding studies of these complexes have been investigated by UV–Vis absorption, ethidium bromide (EB) displacement, fluorescence, circular dichroism and gel electrophoresis techniques. The apparent binding constants (Kapp) has been obtained 3.9 and 10.9×104M−1 at lower concentration range and 1.03 and 1.59×104M−1 at higher concentration range for complexes (1) and (2), respectively. These complexes effectively interact with CT-DNA in the order of (2)>(1). Fluorescence studies exhibited that the complexes quench CT-DNA-EB by simultaneous static and dynamic quenching processes. The calculated binding (Kapp, kq, KSV, n) and thermodynamic (ΔG°, ΔH°, ΔS°) parameters revealed that hydrophobic, van der Waals forces and hydrogen binding holds the Pd(II) complexes in the CT-DNA grooves. Gel electrophoresis supports the spectroscopic experiments.
Synthesis, crystal structure and magnetic properties of trinuclear chromium(III) basic carboxylate assembly: [Cr<inf>3</inf>O(salH)<inf>7</inf>(H<inf>2</inf>O)<inf>2</inf>] (salH<inf>2</inf>=salicylic acid), a new member of [Cr<inf>3</inf>O] family
2016, Journal of Molecular Structure
Synthesizing a novel trinuclear chromium(III) basic carboxylate complex could give rise to new materials with interesting properties. Complex [Cr3O(salH)7(H2O)2] is formed in a one-pot, self-assembly reaction when the inert reaction mixture is exposed to dioxygen. The structural property of the complex has been acquired by single-crystal X-ray crystallography and further characterized by elemental analysis (EA), infrared (IR), UV–Visible (UV–Vis), fluorescence spectroscopy and thermo gravimetric and differential thermal analysis (TG–DTA). X–ray structural analysis shows a slightly distorted equilateral of the Cr triangle. The most important feature of the title complex is the unusual framework of the [Cr3O] family due to a terminal Ph(OH)CO2- ion of Cr(2) center, which is unique among the structurally characterized (μ3-oxo)-trichromium(III) complexes. Variable-temperature magnetic susceptibility studies indicate that the total spin value of the ground state is 1/2.
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FAQs
What are the properties of chromium III? ›
Chromium is a white, hard, lustrous and brittle metal that is extremely resistant to ordinary corrosive agents. Properties vary widely depending on the particular compound. Chromic oxide is a bright green hygroscopic powder with melting point of 2435°C, boiling point of 4000°C and specific gravity of 5.2.
What is chromium III used for? ›Chromium (III), also called Cr (III), is an important nutrient that the body needs to process certain sugars, proteins and fats. Both forms of chromium are used in industry. Chromium (VI) and chromium (III) are used for chrome plating, dyes and pigments, leather tanning and wood preserving.
What is the chemical composition of chrome? ›Natural chromium consists of a mixture of four stable isotopes: chromium-52 (83.76 percent), chromium-53 (9.55 percent), chromium-50 (4.31 percent), and chromium-54 (2.38 percent). The metal is paramagnetic (weakly attracted to a magnet).
Is chromium a metal or nonmetal or metalloid? ›A hard, silvery metal with a blue tinge. Chromium is used to harden steel, to manufacture stainless steel (named as it won't rust) and to produce several alloys. Chromium plating can be used to give a polished mirror finish to steel.
What are the characteristics and properties of chromium? ›Chromium is a lustrous, brittle, hard metal. Its colour is silver-gray and it can be highly polished. It does not tarnish in air, when heated it borns and forms the green chromic oxide. Chromium is unstable in oxygen, it immediately produces a thin oxide layer that is impermeable to oxygen and protects the metal below.
What are 4 physical properties of chromium? ›| Property | Chromium | Chromium(III) chloride |
|---|---|---|
| Physical state | Solid | Solid |
| Melting point | 1,90±10 °C | ≈1,150 °C |
| Boiling point | 2,642 °C | Decomposes at 1,300 °C |
| Density at 20 °C | 7.14 (28 °C)a | 2.87 (25 °C)a |
Chromium and Health. This section focuses on five conditions in which chromium might have beneficial effects: impaired glucose tolerance and diabetes, metabolic syndrome, polycystic ovary syndrome, dyslipidemia, and weight and lean body mass.
What is the use of chromium in everyday life? ›Chromium is used in paints, dyes, stains, wood preservatives, curing compounds, rust inhibitors and many other products. However, the predominant use of chromium is for production of stainless steel and in chrome plating.
What is the difference between chromium and chromium III? ›Chromium III is much less toxic than chromium (VI). The respiratory tract is also the major target organ for chromium (III) toxicity, similar to chromium (VI). Chromium (III) is an essential element in humans. The body can detoxify some amount of chromium (VI) to chromium (III).
Does chrome plated rust? ›Chrome plating will not rust, however when it is damaged - it can appear dull. The metal core can rust if plating is lost through accidental damage or with natural wear over time.
What chemicals remove chrome? ›
Hydrochloric Acid
An acid solution with a 30–40% concentration should be enough to remove chrome. The process is simple enough, taking care to avoid skin contact. First, you'll need to dilute the hydrochloric acid with water in a ratio of 1/3 part acid to 1 part water.
- Mix a 1:1 ratio of vinegar and water. Using equal parts water and vinegar for a solution should be effective but still gentle.
- Use a soft sponge or cloth to wipe the surface. ...
- Add a little baking soda for extra strength. ...
- Once your chrome is nice and clean, consider polishing it!
Naturally resistant to corrosion, chromium does not rust. The element reacts with the surrounding air to form a layer of chromium oxide over stainless steel: known as the 'passive layer', this is what helps to protect stainless steel from rusting.
How toxic is chromium? ›When inhaled, chromium compounds are respiratory tract irritants and can cause pulmonary sensitization. Chronic inhalation of Cr(VI) compounds increases the risk of lung, nasal, and sinus cancer. Severe dermatitis and usually painless skin ulcers can result from contact with Cr(VI) compounds.
What are the dangers of chromium? ›► Chromium may cause a skin allergy. If allergy develops, very low future exposure can cause itching and a skin rash. exposure can cause asthma attacks with shortness of breath, wheezing, coughing, and/or chest tightness.
What are 5 facts about chromium? ›- #1) It's Used in Stainless Steel. It's a little-known fact that stainless steel contains chromium. ...
- #2) It Doesn't Rust. ...
- #3) It's the Hardest Metal. ...
- #4) It Reflects Nearly 70% of Visible Light. ...
- #5) It Was Discovered In the 18th Century.
Chromium is highly resistant to tarnishing, which makes it useful as a metal that preserves its outermost layer from corroding, unlike other metals such as copper, magnesium, and aluminium. Chromium has a melting point of 1907 °C (3465 °F), which is relatively low compared to the majority of transition metals.
Which properties of chromium metal make it suitable? ›The chromium metal is suitable for electroplating it on car bumpers, bath taps and bicycle handlebars, etc., made of iron because it is corrosion resistant and also gives shiny appearance.
What are the 4 major physical properties of metals? ›- high melting points.
- good conductors of electricity.
- good conductors of heat.
- high density.
- malleable.
- ductile.
Physical Properties of Metals
Metals are lustrous, malleable, ductile, good conductors of heat and electricity. Other properties include: State: Metals are solids at room temperature with the exception of mercury, which is liquid at room temperature (Gallium is liquid on hot days).
What are 5 of the physical properties? ›
Physical properties of matter include color, hardness, malleability, solubility, electrical conductivity, density, melting point, and boiling point.
What are five common uses of chromium? ›- In metal ceramics.
- In chrome plating.
- As dyes and paints.
- To produce synthetic rubies.
- In alloys, e.g., stainless steel.
- To manufacture molds for the firing of bricks.
- As a catalyst in dyeing and tanning of leather.
Chromium steel is an alloy that mixes chromium with carbon and iron. This type of steel has many benefits, such as corrosion resistance and a long-lasting finish. However, it also comes with some drawbacks, such as its high cost and difficulty of machining.
Do humans need chromium? ›Chromium is an essential mineral that the body needs in trace amounts. It is naturally present in a wide variety of foods, though only in small amounts, and is also available as a supplement. Chromium enhances the action of the hormone insulin.
What is the role of chromium in human health? ›Chromium is important in the breakdown of fats and carbohydrates. It stimulates fatty acid and cholesterol synthesis. They are important for brain function and other body processes. Chromium also aids in insulin action and glucose breakdown.
Where can you find chromium at home? ›Chromium is a versatile metal that has many uses. If you drive an older car, the bumper may have been chromium plated. The stainless steel fork that you eat your food with contains chromium. If you paint, many dyes and pigments contain chromium.
Is chromium still used today? ›The level of exposure depends upon the dose, duration, and work being done. Hexavalent chromium is used in many industries. It's used in electroplating, welding, and chromate painting.
Is chromium 3 hazardous waste? ›Waste that contains Cr(III) only is considered nonhazardous. Other chromium-containing wastes are “listed” hazardous wastes; these wastes are generated by certain processes, including metal plating. Wastewater treatment sludges containing chromium from electroplating operations carry an F006 hazardous waste code.
Is chromium III toxic? ›Trivalent chromium has low toxicity, meaning it is not very harmful to your body. It does not get absorbed through the gastrointestinal tract or digestion very well and it has been shown that taking dietary supplements containing trivalent chromium is generally not associated with adverse effects.
Can chromium replace chrome? ›A major advantage is that Chromium allows Linux distributions that need open-source software to package a browser almost identical to Chrome. Linux distributors can also use Chromium as the default web browser in place of Firefox.
Will vinegar remove chrome plating? ›
For extra cleaning power, mix equal parts baking soda and white vinegar before applying it to affected areas with an old toothbrush/nail brush; then wipe away with a damp cloth after 5 minutes of leaving it on there to do its magic!
Will vinegar remove rust from chrome? ›Will Vinegar Remove Rust from Chrome? If you prefer natural cleaners, you can use vinegar to remove the rust from your chrome fixtures. The acidic nature of vinegar helps to dissolve rust, but keep in mind, this method takes a little more elbow grease than other options.
Does wd40 remove rust? ›WD-40 can help remove rust from metals like iron, chrome, and stainless steel without further damaging the surface of the metal or removing the paint. The Multi-Use Product is great for loosening and removing excessive surface rust.
What dissolves chrome plating? ›Use hydrochloric acid (muriatic acid).
Hydrochloric, or muriatic, acid, is a strong, corrosive acid. In high concentrations, it can be used to remove chrome plating from metal objects. For removing chrome, an acid solution of about 30-40% concentration should suffice.
Hydrochloric acid is typically used in high concentrations, say 30-40%. To remove the coat, one needs to submerge the chrome-plated material in the acid solution and allow the acid to act. The chrome coating will come off after a while and should be duly removed from the acid solution.
Can alcohol clean chrome? ›Cleaning sinks and chrome.
Rubbing alcohol can make these surfaces clean and shiny again. Pour the alcohol on a soft cloth and clean. You don't have to follow up with water to rinse because the alcohol will evaporate.
Will vinegar damage chrome fixtures? Vinegar is so great at removing rust from chrome because it's an acid, but this does mean you should use it carefully and sparingly and not leave it sitting too long, especially if there isn't a lot of rust or dirt to remove.
Can Windex clean chrome? ›You can use Windex® Ammonia-Free Glass Cleaner on your car's tinted windows, mirrors, glass, chrome, stainless steel, plastic, and vinyl surfaces. For a streak-free shine, clean car windows when the surface is cool and out of direct sunlight whenever possible.
What is the best chemical to remove rust from chrome? ›Removing rust from chrome car parts is easier than you think. Simply spray the affected area with WD-40 Multi-Use Product, leave on for about 10 minutes, then with a light abrasive like a scourer, scrub the surface lightly to remove some of the rust, while avoiding scratching the chrome.
What destroys chromium? ›Since hexavalent chromium is an element that cannot be destroyed, it has to either be physically removed by excavating soil or pumping and treating groundwater or transformed to the less toxic trivalent form and stabilized within the subsurface environment by forming insoluble and immobile trivalent hydroxide ...
Is chromium toxic in the air? ›
If hexavalent chromium is inhaled in high quantities, it can cause irritation or injury to the nostrils, throat, and lungs (respiratory tract). Lung cancer in workers exposed to hexavalent chromium in the air.
Is chromium toxic to touch? ›Skin. Prolonged skin contact can result in dermatitis and skin ulcers. Some workers develop an allergic sensitization to chromium. In sensitized workers, contact with even small amounts can cause a serious skin rash.
Which organs are damaged by chromium toxicity? ›Lung cancer is a potential long-term effect of chronic Cr(VI) exposure. Besides the lungs and intestinal tract, the liver and kidney are often target organs for chromate toxicity from chronic exposure.
What is the most toxic form of chromium? ›Among these, hexavalent chromium is considered as the most toxic form because it readily passes cellular membranes and then reduced to trivalent form.
What is the target organ of chromium toxicity? ›the respiratory tract is the primary target organ for inhaled chromium. ingestion of large amounts of chromium (VI) can lead to severe respiratory, cardiovascular, gastrointestinal, hepatic and renal damage and potentially death. chromium (VI) may cause occupational asthma in sensitised individuals.
Is chromium hard on kidneys? ›The chromium found in foods will not hurt you. But taking excessive chromium supplements can lead to stomach problems and low blood sugar (hypoglycemia). Too much chromium from supplements can also damage the liver, kidneys, and nerves, and it may cause irregular heart rhythm.
Who should not take chromium? ›Chromium from food and dietary supplements does not appear to cause any harm, but research is limited. People with kidney disease or liver disease should be cautious about taking high amounts of chromium.
Is chromium a neurotoxin? ›Hexavalent chromium [Cr(VI)] is a global environmental pollutant that increases risk for several types of cancers and is increasingly being recognized as a neurotoxicant.
Why is chromium +3 most stable? ›Cr3+is more stable in aqueous solution due to higher hydration energy which is due to smaller size and higher charge.
Why is chromium +3 stable? ›ANS: (i) It is because Cr2+ loses electron to become Cr3+ which is more stable due to half filled t2g orbitals, whereas Mn3+ will gain electron to become Mn2+ which is more stable due to half filled Page 2 2 d-orbitals.
What is the structure of chromium III? ›
The configuration around the chromium(III) ions is octahedral, with a mean Cr−O bond distance of 1.97(1) Å. The hydrolyzed chromium(III) complex at a pH = 15 is most probably a polymeric chain with double hydroxo bridges [Cr(μ2-OH)2(OH)2]nn−, with mean Cr−O and Cr···Cr distances of 2.00(1) and 2.98(1) Å, respectively.
Why is chromium the hardest metal? ›Cr and Mo have a maximum number of unpaired d-electrons which makes them very hard due to an increase in the number of covalent bonds.
Why is chromium strong? ›Naturally resistant to corrosion, chromium does not rust. The element reacts with the surrounding air to form a layer of chromium oxide over stainless steel: known as the 'passive layer', this is what helps to protect stainless steel from rusting.
What is the most stable element Why is it so stable? ›It turns out that the most stable atom of all, because it has the largest average binding energy per nucleon, is a particular isotope of iron (iron-56). The nuclei higher up the periodic table are not as stable, which is why radioactive decays, and fission, occur.
Is chromium 3 bad? ›chronic inhalation of chromium (III) salts causes a range of inflammatory changes in the respiratory tract. chronic inhalation of high levels of chromium (VI) (in poorly controlled occupational settings) may cause nasal septum ulceration and perforation, respiratory irritation, lung cancer and possible renal effects.
What problems are caused by chromium? ›- When inhaled, chromium compounds are respiratory tract irritants and can cause pulmonary sensitization.
- Chronic inhalation of Cr(VI) compounds increases the risk of lung, nasal, and sinus cancer.
- Severe dermatitis and usually painless skin ulcers can result from contact with Cr(VI) compounds.
Chromium is an element that has a high affinity for oxygen. As a result, it forms a thin layer of chromium oxide on its surface when it comes into contact with air or water. This chromium oxide layer acts as a barrier between the metal and the environment, preventing further oxidation and corrosion from occurring.
What are the pros and cons of chromium? ›Chromium steel is an alloy that mixes chromium with carbon and iron. This type of steel has many benefits, such as corrosion resistance and a long-lasting finish. However, it also comes with some drawbacks, such as its high cost and difficulty of machining.
What is the difference between Cr3 and Cr6? ›Chromium converts back and forth between Cr3 and Cr6. Cr3 is an essential nutrient in the diet and has low toxicity. Cr6 is more toxic and is known to cause cancer when inhaled. The two forms of chromium convert back and forth in in the human body and in water under different environmental conditions.
Can chromium replace Chrome? ›A major advantage is that Chromium allows Linux distributions that need open-source software to package a browser almost identical to Chrome. Linux distributors can also use Chromium as the default web browser in place of Firefox.
Why is chromium 3 more stable than chromium 2? ›
Cr3+ is more stable than Cr2+ in aqueous solutions. It is because of greater hydration enthalpy of Cr3+ ions due to its small size and higher charge.
What is chromium III also known as? ›Chromium(III) boride, also known as chromium monoboride (CrB), is an inorganic compound with the chemical formula CrB.
What is the reaction of chromium III chloride? ›Anhydrous chromium(III) chloride reacts with pure carboxylic acids (RCOOH where R = CH3, C2H5, n-C 3 H7, CH2CI, CHCI2 and CC13 ) to give basic trinuclear chromium(III) carboxylates of the general formula [Cr30(00CR)6] + Cl~.