Talk:Infrared spectroscopy correlation table

Assessment

This article suffers from insufficient context, and the table is not referenced (though references for IR correlations are widely available). Also, the format of the chart has an appearance that I find annoying. Otherwise, it's fine. Shalom (Hello • Peace) 01:17, 12 October 2007 (UTC)

Well this table is usually found in textbooks for organic chemists and not in encyclopedias. But the english version does not seem to be that strict about what Wikipedia is not. Matthias M. (talk) 17:03, 3 July 2009 (UTC)

I don't understand your comment. If we put in melting points, why not IR specs? OxygenBlue (talk) 10:41, 13 December 2012 (UTC)

Correlations

The methyl peak at 1260 cm^-1 (strong) is very specific for methyl bonded to silicium (CH₃-Si). This should be specified in the table. --Langbein Rise (talk) 08:40, 14 November 2008 (UTC)

New version

I have a draft new version of the table ready at my user page. Feel free to browse and comment. I could use some suggestions for a sortkey for the group column. Probably it is also a good idea to create a second, concise version of the table that lists only the most important absorption ranges and can function as a quick reference. --Tweenk (talk) 01:06, 18 January 2009 (UTC)

Yours looks good and it's referenced which is a big plus. Matthias M. (talk) 17:03, 3 July 2009 (UTC)

the one on your user talk is vastly better - I wish I had seen it sooner. —Preceding unsigned comment added by 82.1.124.141 (talk) 17:11, 20 October 2010 (UTC)

I approve the new one a lot! OxygenBlue (talk) 10:43, 13 December 2012 (UTC)

New version

Since it is mentioned, that IR is valuable for inorganic compounds, an extension with complexes and salts would be appropriate. Does anyone know if this is common available? OxygenBlue (talk) 10:41, 13 December 2012 (UTC)

I added a link to Kazuo Nakamoto (16 January 2009). Infrared and Raman Spectra of Inorganic and Coordination Compounds, Applications in Coordination, Organometallic, and Bioinorganic Chemistry. John Wiley & Sons. pp. 9–. ISBN 978-0-470-40587-1. Retrieved 13 December 2012. It may take some work to construct a table. --Kkmurray (talk) 13:57, 13 December 2012 (UTC)

Conversions to nm

I know it may be helpful to have IR data in nm but in most cases, anything after the first significant figure is meaningless. It's clear that a well-intentioned someone just converted each figure and copied the exact number to the table. Take this entry;

Bond	Type of bond	Specific type of bond	Absorption peak cm-1 (nm)	Appearance
N-H	secondary amines	any	>3000 cm−1 (>3333 nm)	weak to medium

In this case, >3000 cm⁻¹ is just giving a rough estimate for the lower bound on secondary amines, with a precision of only one significant figure. >3333 nm, on the other hand, suggests that this is a much more accurate measurement of the wavelength, and anyone relying on this page would consider 3400 nm to be out of this range. Also, greater than 3000 cm⁻¹ implies higher frequencies, whilst greater than 3333 nm implies lower (longer wavelength). I'm guessing the latter should be less than. Tomásdearg92 (talk) 15:29, 29 January 2013 (UTC)

So there are other page watchers. 21 months after the above comment, I'm going to WP:BOLDLY delete the nanometre values because they are at best misleading—and in their current state, useless. If anyone objects, reply. Tomásdearg92 (talk) 21:04, 23 October 2014 (UTC)

Support removing nm from the table. Conversion factors can be noted in the article body. --Kkmurray (talk) 21:30, 23 October 2014 (UTC)

 Done But not the conversion, yet. Tomásdearg92 (talk) 00:13, 30 October 2014 (UTC)

Support removing nm and keeping them removed. It is actually mathematically incorrect to convert features (peaks and troughs) of a distribution curve this way (whether a probability distribution or spectrum), and can introduce errors as high as single digit percents for common IR spectra, and as high as 76% for very broad spectra like the solar spectrum (case in point: the peak of the solar spectrum in wavelength is Green-Visible while in frequency it's Infrared). Converting one's entire curve to the axis used by the literature (wavelength vs wavenumber/frequency/photon-energy) then calculating the peaks will give the correct values that can be compared to the literature, while taking peaks and converting them alone will give slightly- to very- incorrect values. (Though it's less of an issue the narrower the peak/trough, which explains why you can get away with it in atomic gas emission lines). --RProgrammer (talk) 22:01, 3 August 2020 (UTC)

Clarification

The fact that my suggested changes were incorrect and reverted, highlights the need for clarification regarding the intended bond and containing structure to remove ambiguity. Furthermore, it is not obvious whether the vibrations are stretching, or deformational. Plasmic Physics (talk) 23:31, 21 October 2014 (UTC)

You aren't necessarily incorrect, I just want to get a naming consensus per WP:BRD. Specifically, I found the proposed symbols somewhat obscure and prefer methylene to methanediyl, etc. But, to avoid WP:OR, the table headings should follow current secondary sources. What do the current textbooks use to describe group frequencies? That should be the starting point. --Kkmurray (talk) 02:59, 22 October 2014 (UTC)

Phosphorus oxide

Clarification about the meaning of "free" and "bonded" phosphorus oxide would be nice, especially since searching both google and wikipedia for the phrases only yields a single result that's hardly more helpful than this table. --RProgrammer (talk) 22:10, 3 August 2020 (UTC)