AUTHOR OF THIS BLOG

DR ANTHONY MELVIN CRASTO, WORLDDRUGTRACKER

1-PENTANAL NMR

 Uncategorized  Comments Off on 1-PENTANAL NMR
Jul 222014
 

 

 

Formula: C5H10O

C5H10O
Rule 2, omit O, gives C5H10
5 – 10/2 + 1 = 1 degree of unsaturation.
Look for 1 pi bond or aliphatic ring.

IR spectrum

The band at 1727 indicates a carbonyl, probably an aldehyde; an aldehyde is also suggested by the band at 2719 which is likely the C-H stretch of the H-C=O group. The bands at 3000-2850 indicate C-H alkane stretches.

 

 

 

NMR spectrum

 

Structure answern

 

NMR answer

 

Proton NMR Spectrum

Since the IR spectrum indicates an aldehyde, look for this functionality in the NMR spectrum. The aldehydic proton appears in the NMR from 9-10, usually as a small singlet.

The spectrum above shows a small singlet corresponding to one proton at 9.2 ppm, confirming that the compound is an aldehyde. Protons on the carbon adjacent to the aldehyde carbonyl will show up at 2-2.7 ppm; this is the triplet peak of 2 protons at 2.4 ppm on the above spectrum. Thus, so far we know that there is an aldehyde group next to a methylene group which is next to a carbon that has two hydrogens:

This accounts for 3 of the 5 carbons in the molecule. The un-colored hydrogens in the above structure could correspond to the peak of 2 hydrogens centered at 1.6 ppm; this peak is a pentet indicating that these protons are adjacent to carbons with a total of 4 hydrogens. The peak centered at 1.35 ppm has two hydrogens and is a sextet, indicating it is next to carbons that have a total of 5 hydrogens. Finally, the peak at 0.9 ppm has 3 hydrogens and is a triplet, indicating it is a methyl group adjacent to a carbon that has 2 hydrogens. Therefore, it looks like the molecule is a straight-chain of 5 carbons with the aldehyde group at one end:

Note that the closer a group is to the carbonyl function, the further downfield it is shifted. Here is how the NMR correlates to the structure:

MASS SPECTRUM

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The three key days of immunodeficiency virus

 AIDS  Comments Off on The three key days of immunodeficiency virus
Jul 222014
 

Structure of simian virus very similar to human. / SUPERSTOCK / AGE FOTOSTOCK

Three days is what it takes for the virus simian immunodeficiency (SIV), the most similar to HIV, to reach reservoirs (cells in which it is to siemrpe) microorganism. The measurement, which made ​​scientific accuracy of Beth Israel Deaconess Medical Center in Boston, is key to preventing the affected macaque becomes a carrier for life VIS. The study sheds light on what happens in humans with HIV, and explains some of the latest achievements and disappointments that research has this infectious agent in recent years. The work is published in the latest edition ofNature.

READ AT

http://sociedad.elpais.com/sociedad/2014/07/20/actualidad/1405875909_623856.html

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