Nitrogen Systems: First Positive, Second Positive, First Negative

[Yohan24]

What is the "first positive", "second positive", "first negative" systems of nitrogen

Hello,
I have been trying to catch up on spectroscopy theory, and I'm trying to get a grasp on what all the terms mean. I constantly seem the terms "first positive system", etc... coming up, and I'm not sure I understand what that means in terms of the transitions that are taking place, what state the molecule is in and so on. I've looked all over but it seems most articles that I find take it for granted that everyone knows what these things mean. Maybe I'm over thinking, or not thinking at all. Any assistance would be greatly appreciated.
Cheers.
- Y

 

[hggreen]

Hi Yohan24,

I am literally searching for the same thing and I found the following paper talks a bit about the first positive and second positive(at p118)
http://www.stanford.edu/group/Zarelab/publinks/13.pdf

Hope this helps. Please let me know if you find anything in more detail. Thanks!

Cheers,
hggreen

 

[DrClaude]

In G. Herzberg, Molecular Spectra and Molecular Structure. I. Spectra of Diatomic Molecules (Van Nostrand, Princeton, 1950), footnote on page 51:

The designation negative and positive groups (or bands) refer to the occurrence of these bands in the negative glow or the positive column, respectively, of an electric discharge. The positive groups are due to the neutral molecule, the negative groups to the singly positively charged molecular ion.

 

[ZapperZ]

Unfortunately, this was the OP's only post, and he/she hasn't come back since May 29, 2012.

Zz.

 

[DrClaude]

Unfortunately, this was the OP's only post, and he/she hasn't come back since May 29, 2012.

Zz.

I saw that, but I answered anyway as the information seemed of interest to hggreen.

 

[hggreen]

Thank you DrClaude! That helps a lot.

-hggreen

In G. Herzberg, Molecular Spectra and Molecular Structure. I. Spectra of Diatomic Molecules (Van Nostrand, Princeton, 1950), footnote on page 51: