- #1
noxflos
- 10
- 0
Okay I am lost. My Professor has given me the formula ( C4 H8 Br2) and the signals 3.8(s, 2H) and 1.8(s, 6H). How the hell am I suppose to compose a molecule from that?? Any ideas?
Bystander said:Six equivalent hydrogens? Two equivalent hydrogens? A four carbon skeleton? Two bromines? It doesn't get any simpler --- try reading the book.
H NMR (proton nuclear magnetic resonance) is a common technique used in chemistry to determine the structure of molecules. It involves placing a molecule in a strong magnetic field and measuring the energy absorbed by the hydrogen atoms. The resulting spectrum can be used to identify the types and number of hydrogen atoms present, providing clues about the molecule's structure.
An H NMR spectrum can provide information about the number and types of hydrogen atoms present in a molecule, as well as their chemical environment. This can help in determining the connectivity and structure of the molecule, as well as the functional groups present.
The chemical shift is a measure of the electron density surrounding a hydrogen atom. Different functional groups have unique electron distributions, which result in different chemical shifts. By comparing the chemical shifts in an H NMR spectrum to a database of known values, it is possible to identify the functional groups present in a molecule.
1H NMR uses hydrogen atoms as the nuclei to produce a spectrum, while 13C NMR uses carbon atoms. Since carbon atoms are less abundant than hydrogen atoms in most molecules, 13C NMR is less sensitive and requires more time to obtain a spectrum. However, 13C NMR can provide additional information about the carbon-carbon bond connectivity in a molecule, which is not possible with 1H NMR.
H NMR can be used to determine the purity of a sample by comparing the integrated areas of the peaks in the spectrum. The integrated area represents the number of hydrogen atoms present in each type of molecule, so a higher purity sample will have sharper and more distinct peaks. Impurities will result in additional peaks or smearing in the spectrum, indicating a lower purity sample.