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For more information, please see full course syllabus of Organic Chemistry Lab
Organic Chemistry Lab Infrared Spectroscopy, Part II
This lecture provides a basic, systematic approach to interpreting an IR spectrum. Start by reading from left to right looking for obvious peaks, like broad OH or NH peaks around 3300 cm-1 (this may be contamination from water). At 3000, look for sp² CHs, and just to the right for sp³ CH. Aromatic or alkene signals will also show up as strong fingerprint peaks below 1000. Triple bonds show up around 2200 as weak peaks, and carbonyls appear around 1700 as strong peaks. Conjugation lowers the number. Then, identify less obvious bands. Sp-hybridized CH bonds also appear around 3300 but as a sharp peak. Aldehyde CH groups have small double peaks at 2850 and 2750. C-O stretches may appear around 1050 as weak peaks in the fingerprint region. The lecture ends with eight examples and ten practice problems.
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1 answer
Wed Jan 8, 2020 7:12 PM
Post by Siavash Gholizadeh on December 3, 2019
Hi Dr. Starkey,I can't open the "IR problem-solving approach.doc" document in the exercise files (the error says that it's corrupted). I also have a question: will you post lectures on any of the following subjects: organometalic chemistry, UV spectroscopy, column chromatography or HPLC? If you will, could you please specify the date?
Thank you
1 answer
Thu Oct 6, 2016 1:07 PM
Post by Tane Boghozian on October 4, 2016
Hi Dr. Starkey, I have been using educator. com for almost four months and its great!
Thank you very much for the great lectures. I have learned a lot. I have a question about your availability. Would be possible to talk to you about my experiments and research whenever I have questions? will you answer my questions?
Thanks a lot for your help.
1 answer
Thu Aug 13, 2015 9:59 AM
Post by sandi imayeguahi on August 13, 2015
That was your best lecture by far. Your really great.
1 answer
Sun Apr 26, 2015 9:49 PM
Post by Nagasrinivas Tripuraneni on April 26, 2015
Professor, thank you for the informative lecture.
1 answer
Fri Oct 18, 2013 2:10 PM
Post by brandon oneal on October 18, 2013
The only question I have is how can you tell which compound it is?
1 answer
Sun Jul 21, 2013 10:44 PM
Post by Parabjit Kaur on July 21, 2013
when will you post lectures on the mass spectrometry ?
1 answer
Thu May 9, 2013 10:19 AM
Post by Nawaphan Jedjomnongkit on May 6, 2013
If we have internal and symmetrical alkyne, can we differentiate from normal alkane? Because what we can get from IR spectrum is only SP3 CH no SP CH and CC triple bond.
1 answer
Sun Feb 3, 2013 11:03 PM
Post by Ramin Sadat on February 3, 2013
Will you be posting anything on Mass spectrometry ?
1 answer
Tue Jan 29, 2013 9:47 PM
Post by Edi William Yapi on January 29, 2013
Good Lord.... You are just a great instructor !
1 answer
Sun Jan 13, 2013 11:54 AM
Post by Janaki Dharmarpandi on January 12, 2013
you are awesome!!!!
1 answer
Sun Dec 2, 2012 11:43 AM
Post by ali aden on December 1, 2012
you are amazing, i did understand this material, excepts i have a little confussion o the finger print area.
1 answer
Mon Aug 13, 2012 9:05 PM
Post by Daniel Ugsang on August 10, 2012
Honestly, you are a LIFE SAVER. My O-chem prof is good but goes off on tangents. You get right to the point. Succinct. Good explanations. I really hope I pass Ochem and if I do, it'll be because of you, Professor Starkey!
1 answer
Tue Jul 17, 2012 9:55 AM
Post by nouf alkusayer on July 7, 2012
U r amazing !!!!
1 answer
Fri Feb 3, 2012 11:33 PM
Post by Lukasz Skora on February 3, 2012
Hi Dr. Starkey, awesome lectures! They are life savers!. I have a question, does it depend on the finger print region if you wanted to deduce how long the compounds is. How for example can one tell if it's a butane or a decane, or like pentanol, hexanol, or octanol. They are all sp3 CH's with an alcohol at the end. Or a benzene with a longer substituent compared to a shorter one. Thank you.
0 answers
Post by Thomas Notto on November 23, 2011
Great Job on the basics of Infrared Spectroscopy... I think I got now!!!