Math & Science ⇒ Specific rotation symbol (chemistry)

[muchalh]

Hi,

Does anyone of you chemists know what is the code for the specific rotation symbol (alpha D 20)? I looked through siunitx, mhchem and briefly through the LaTeX symbol list but I couldn't find it. Wikipedia has it right and I'm guessing they generated it using LaTeX but I don't know how.

Hubert.

[gmedina]

Hi,

providing the link to that symbol would be really helpful for non-chemists like me.

[localghost]

I suggest to read the article on Wikipedia [1]. The representation can differ in each language.

[1] Specific rotation - Wikipedia, the free encyclopedia


Best regards
Thorsten

[josephwright]

I'd put

Code: Select all

\( \alpha_{\textup{D}}\)

. It's a variable (alpha, the specific rotation) with a descriptor ("D", the wavelength of the sodium "d-line" emission). The usual rules of typography then apply: in English variables should be italic, non-variable descriptors should be upright.

[BoudewijnD]

Hey Muchalh,

I use this piece of code for my alpha D. As far as I know this is accepted for all the major journals.

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[$\alpha$]$^{23}_{\textsc{d}}$ -4\degree (c = 0.2, \ce{CHCl3}).

\BoudewijnD

[muchalh]

Hello all,

Thanks for replies and sorry for not including Wikipedia'a reference page.

@josephwright
I was hoping you would know this. Thanks for your lead. By the way, according to your explanation, Wikipedia entry is slightly incorrect("D" is italic). I checked ACS style quide and you're right - the "D" should be upright.

Specific rotation should include the temperature of the measurement. Using Joseph's example I came up with the following code for specific rotation of 35.4 degrees at 20 deg Celsius using sodium D-line light source:

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\( [\alpha]_{\textup{D}}^{20}\) \num[addsign=all]{35.4} (\textit{c} 1.00, \ce{CHCl3})

c = concentration (here in chloroform) in g/100 mL
the degree sign is not used

the "addsign=all" option is needed to display "+" sign for positive values. Looks OK after compilation but please correct me if it's not OK.

Cheers,

Hubert

[BoudewijnD]

as far is I know the D must me a small cap!

see http://pubs.acs.org/paragonplus/submiss ... hguide.pdf

page 9


\BoudewijnD

[muchalh]

I generated symbols using normal and small caps "D" and compared to the symbol in the ACS guide[1]. The normal version is closer to the symbol printed in the book. However, both versions look very similar. I also took one of the recent ACIE papers and compared the symbols and the 'small caps' version appears to be correct. Just pick one and stick to it:-)

Thanks for the discussion.

Hubert

[1] ACS Style Guide, 3rd ed.