Talk:Nickel

Cuban Nickel

major production areas include should mention Cuba's mines which constitute a double digit portion of global production 64.179.189.25 (talk) 17:11, 23 March 2023 (UTC)

Not done. Please provide a reliable source 2603:8080:D03:89D4:4CEA:FD5B:6E65:90A (talk) 02:14, 10 September 2024 (UTC)

Semi-protected edit request on 28 March 2025

I think nickel should have also the info that it affects enviornment and people's health with air and water and soil pollution 172.103.229.189 (talk) 23:17, 28 March 2025 (UTC)

 Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. Cannolis (talk) 00:03, 29 March 2025 (UTC)

Actually the section "Toxicity" already contains much information about environment and effects on health. Dirac66 (talk) 10:50, 29 March 2025 (UTC)

Hi there, just to give you a sense of what the toxicity chapter could entail, here's what German WP has on the topic: "Nickel metal and many nickel compounds are classified as carcinogenic, germ cell mutagenic (genotoxic) and toxic to reproduction (reproductive toxicant) – CMR – as well as skin and respiratory sensitizers. Inhalation of inorganic nickel compounds is associated with an increased risk of squamous cell carcinoma of the lung and upper respiratory tract. Such malignant neoplasms are recognized as occupational diseases in Germany in cases of occupational exposure (BK 4109).[45] The current classifications of the various nickel compounds according to Regulation (EC) No. 1272/2008 and according to the Technical Rules for Hazardous Substances (TRGS) 905 and TRGS 907 can be found in the GESTIS substance database or the hazardous substances list[46] of the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA). For nickel metal, an occupational exposure limit (OEL) of 6 µg/m³ was published for the first time in 2015 in the alveolar fraction (A fraction) and, in 2018, an additional OEL of 30 µg/m³ was published in the inhalable fraction (E fraction) in TRGS 900. [47] Nickel and its compounds can be absorbed through the respiratory tract, with food, or through the skin. The general population mainly absorbs nickel through food; inhalation exposure is low. For occupationally exposed individuals, absorption via the respiratory tract is usually the main route. Although no acute toxic effects are to be expected, prolonged exposure can lead to pulmonary and renal toxicity in particular; teratogenic and respiratory sensitization effects have also been observed.[47]" Satu Katja (talk) 15:09, 26 July 2025 (UTC)

Semi-protected edit request on 20 November 2025

Removal of Nickel (VI) section

This section is incorrect and should be removed.

The Boronski paper this section cites clearly describes the Ni(BeCp)6 complex as being high-valent low-oxidation state. Their use of Lowdin Population Analysis to computationally determine the oxidation state of the nickel lead them to tentatively assign it an oxidation state between 0 and -1. (The entire point of the paper was that strong sigma-donation of the Be in the BeCp ligands stabilizes this complex and allows it to exist at low oxidation state.)

Moreover, the system does not have a trigonal pyramidal molecular geometry, that would require it to have 3 ligands attached. It has 6 ligands and would, at best, be considered a trigonal prismatic geometry, the authors of the Boronski paper describe the geometry as C3v given that it has an upper and lower deck each containing 3 BeCp ligands (with a toroidal band of electron density in the middle). Lwgiordano (talk) 15:45, 20 November 2025 (UTC)

Perhaps it should just be renamed, say to "Hexavalent nickel". If I understand correctly, the two-sentence text is correct but the oxidation state is not so we cannot call put Ni(VI) in the title. We could instead add a sentence at the end saying that the Boronski paper shows that the oxidation state is not Ni(VI) but closer to Ni(0). Dirac66 (talk) 16:09, 20 November 2025 (UTC)

Question: How exactly is this section incorrect? I would like to know more. NotJamestack (✉️|📝) 16:13, 20 November 2025 (UTC)

Sorry for the slow reply, I didn't get any notifications.

Nickel Charge Issue:

So, the BeCp ligands are exceptionally unusual. The authors of the Boronski paper refer to them as X-type ligands, except the BeCp ligands are neutrally charged (normally x-type ligands are anionic), and the Be in each ligand is acting as a powerful sigma donor.

The nickel complex was synthesized by reacting diberyllocene (CpBeBeCp) with biscyclooctadiene nickel(o). There was no indication of any kind of charge transfer. And the only way the authors were able to ascertain the charge of the nickel was via Lowdin Population Analysis (the were unable verify experimentally via X-ray absorption spectroscopy.) The results of their LPA computations was that the charge of the nickel was between 0 and -1, not +6.

If I were to reword that initial entry, it'd be as:

"As of 2024, a hexavalent Nickel complex, Ni(BeCp)6, was crystallized. Calculations via Lowdin Population Analysis showed it to have a charge between 0 and -1 instead of +6."

Geometry Issue:

So, the entry lists it as trigonal pyramidal, but that that would require the complex to have only 3 ligands. This complex has 6 of the BeCp ligands. Those ligands are split into an upper deck and a lower deck. (Upper deck the ligands are 81.6 degrees apart, lower deck they are 101.9 degrees apart.)

The authors refer to the geometry as C_3v for the entire paper. Trigonal pyramidal is very incorrect because it would imply only 3 ligands. It might be better to call it a distorted trigonal prismatic structure. If I were to reword this it'd be as:

"Notably, the geometry from X-ray Diffraction spectrometry revealed an unusual C3V geometry (akin to a distorted trigonal prismatic geometry) instead of a typical octahedral geometry." ~2025-36207-33 (talk) 16:00, 26 November 2025 (UTC)

Note: Marking as answered while we wait for a response from the requester. - Umby 🌕🐶 (talk) 00:02, 21 November 2025 (UTC)

The section is correct except for the title Nickel (VI). As explained in the Boronski paper, the complex is hexavalent (high valence) but with a low oxidation state closer to Ni(0) than Ni(VI). So I am now going to leave the text alone, but change the title from Nickel(VI) to Hexavalent Ni.Dirac66 (talk) 02:51, 24 November 2025 (UTC)

Sorry, the trigonal pyramidal geometry is very incorrect and would imply that the complex only has 3 ligands. It would be closer to describe it as similar to a distorted trigonal prismatic geometry. Lwgiordano (talk) 16:05, 26 November 2025 (UTC)