-4
$\begingroup$

So 2 answers I am not looking for is HI and formic acid. Although both of them are acids, HI and formic acid are not doing the reducing, but their conjugate forms, I- and HCOO- are doing the reducing, after protonation.

However, I would expand this question to also looking for other examples besides HI and formic acid analogies. Already taken that HCl and HBr being too weak of reducers. So therefore who else besides HI and formic acid in that category.

If the answer is, there isn't any, I would find that interesting knowing that something that is a strong base and a strong oxidizing agents exist, but without a conjugate acid form of that base. By that I mean, strong base medium-strong oxidizer or medium-strong base strong oxidizers exist, without the conjugate acid form.

Improve this question
$\endgroup$
12
  • 3
    $\begingroup$ How could be HI or HCOOH (or their anions) strong oxidizing agents? // You should finally learn some thorough elaboration of your questions, including compact results of prior research. Your questions often seem to be made from the same, rather weird question template. $\endgroup$
    – Poutnik
    Commented Oct 10, 2023 at 14:48
  • 1
    $\begingroup$ Review the guide How to ask and Asking FAQs to prevent clarification requests, objections, down-voting or closure. $\endgroup$
    – Poutnik
    Commented Oct 10, 2023 at 14:49
  • 2
    $\begingroup$ Try to reformulate your question to be clear, it looks rather like a puzzle. Topics may be puzzles, but questions should not be. And elaborate it. If you do not put enough effort to formulate the question text, why to expect responders would put enough effort to their answers? $\endgroup$
    – Poutnik
    Commented Oct 10, 2023 at 15:00
  • 1
    $\begingroup$ Something like HCo(CO)4 would be my guess, but I have no idea how good a reducing agent it actually is, and with a pKa of 1 (en.wikipedia.org/wiki/Metal_carbonyl_hydride) some might debate if it is a strong acid. $\endgroup$
    – Ian Bush
    Commented Oct 11, 2023 at 7:10
  • 3
    $\begingroup$ IF Neal only spent all the time wasted by debating/rewriting/reopening rather on proper elaboration of his questions before posting them..... $\endgroup$
    – Poutnik
    Commented Oct 11, 2023 at 8:08

2 Answers 2

Reset to default
2
$\begingroup$

Though I perceive the formulation of the question would benefit a revision for clarity, an answer constrained to the first half to the title of your question can hint to ascorbic acid (often named vitamin C):

enter image description here

For one, it is not an organic acid with a carboxylic group. However, by its first $\text{p}K_a = 4.10$ (ref), this compound is a little bit more acidic, than acetic acid ($\text{p}K_a = 4.756$, ref).

Second, it is a known antioxidant of high relevance in (e.g. food) technology and biochemistry both in one- as well as two-electron redox reactions. Hence it is not surprising ascorbic acid (and its derivatives) was of research interest for long time, and still is (e.g. [1, 2]). Here, the motif of enediones adjacent to carbonyl group can yield a diketone, a characteristic feature of the reductones.

enter image description here

(credit to Boorsook and Keighley, 1933)

[1] Borsook, H.; Keighley, G. Oxidation-Reduction Potential of Ascorbic Acid (Vitamin C). PNAS 1933, 19, 875–878. doi 10.1073/pnas.19.9.875 (by now available as open access).

[2] Matsui, T.; Kitagawa, Y.; Okumura, M.; Shigeta, Y. Accurate Standard Hydrogen Electrode Potential and Applications to the Redox Potentials of Vitamin C and NAD/NADH. J. Phys. Chem. A 2015, 119, 369–376. doi 10.1021/jp508308y.

Improve this answer
$\endgroup$
4
  • 1
    $\begingroup$ But I think AA is antioxidant due its anion. Its solution is more or less stable for hours, I guess. But if alkalized by NaOH, it gets intense yellow within dozens of seconds or few minutes. $\endgroup$
    – Poutnik
    Commented Oct 10, 2023 at 19:18
  • $\begingroup$ I was already aware of ascorbic acid, but speaking of that, does anyone know what's the name of the tetrahydrofuran ring of ascorbic acid? Tetrahydrofuran is if it has no double bonds, whereas furan has 2 double bonds but in different locations from ascorbic acid. $\endgroup$
    – Neal Conroy
    Commented Oct 10, 2023 at 21:46
  • $\begingroup$ I would name the ring as a lactone ring. And the idea of the antioxidant action coming from the anion is right; blood pH is three units above the pKa. $\endgroup$
    – Oscar Lanzi
    Commented Oct 10, 2023 at 23:24
  • 1
    $\begingroup$ @NealConroy Based on a similarity search in the Wikipedia structure explorer, the of 2-furanone is an other one (includes the C=O, more than merely 2,5-dihydrofuran). $\endgroup$
    – Buttonwood
    Commented Oct 11, 2023 at 8:40
0
$\begingroup$

The best definition of acids and bases are electron pair acceptors-acids and electron pair donors-bases. These reactions can be considered as 2-electron redox reactions or possibly a quick two step one electron transfers. Redox reactions take this one step lower to one electron transfers, indeed most redox reactions are probably a sequential set of one electron transfers. My point is that the two types of reactions are hopelessly intertwined.

Oxidative or reductive strengths are relative. Your requirements are confusing. Possibilities that might match your criteria are the intermediate oxidation states of elements such as chlorine, nitrogen and sulfur and the metals in the first transition series, especially manganese and chromium. Their reactions can be a complicated mix of acid-base reactions and electron transfers.

Improve this answer
$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.