Talk:Palladium disulfide

Oxidation state

@Benjah-bmm27: Regarding your revert on May 2, I think palladium sulfide = PdS = palladium(II) sulfide and palladium disulfide = PdS₂ = palladium(IV) sulfide. Chemical Abstracts lists "palladium disulfide" and "palladium(IV) sulfide" as synonyms (CAS#12137-75-6), but does not include "palladium(II) sulfide" as a synonym. Both the wikidata item (w:wikidata:Q4445867) for this chemical compound and the Russian Wikipedia article (w:ru:Сульфид палладия(IV)) use titles which indicate Pd(IV). Clearly "palladium(IV) sulfide" is a commonly used synonym for this chemical compound and shouldn't have been removed from the infobox's place for synonyms. In chemical nomenclature, assignment of oxidation states are formalities, and in some cases no assignment is going to fully represent intricate details of chemical bonding (as, for example, described in the cited source you mention in your edit summary). I see no reason to say that "palladium(IV) sulfide" is wrong here or that "palladium(II) sulfide" is a better or more appropriate name. 108.16.195.233 (talk) 23:41, 5 May 2021 (UTC)

I understand why PdS₂ appears to be a palladium(IV) compound at first glance, but the crystal structure and XPS show that it is really palladium(II). This is examined in detail in reference 3 in the article, Z. Anorg. Allg. Chem. (2017) 643, 1415-1423. Calling in palladium(IV) sulfide in the article will reinforce that misunderstanding. Palladium(IV) sulfide does redirect here. Palladium(II) sulfide is a different compound, PdS, but PdS₂ can reasonably be described as palladium(II) disulfide. It consists of (formally) Pd²⁺ and S₂²⁻. It cannot reasonably be described as Pd⁴⁺ and S²⁻. We could add more text explicitly stating it is Pd(II) not Pd(IV). It is not true that oxidation states are purely formalities - there is underlying truth and describing this compound as Pd(IV) is more wrong than just glossing over some intricacies. You don't see pyrite described as iron(IV) sulfide. --Ben (talk)