Question

What is mass spectroscopy? Provide an example spectrum from the literature and walk through the interpretation. Do not talk about metal carbonyl clusters. and What is nuclear magnetic resonance spectroscopy?. What information can be gained from 1H NMR spectroscopy?

Answer 1

mass spectrometry

1. studies effect of ionization energy on molecules
2. reactions in gaseous phase leads to the formation of ionic and neutral species
3. arranged them according to mass/relative charge ratio and
4. checked for relative abundance

uses

1. to identify the unknown compound in the sample
2. elucidate the structure and chemical properties of different molecules in the sample
3. analyzing large biomolecules like lipids, proteins, peptides

NMR spectroscopy

based on the principle atomic nucleus spinning randomly in absence of external magnetic field in presence, nuclei align with or against an external magnetic field

nuclei align with an external magnetic field spins at lower energy

nuclei align with against an external magnetic field spins at higher energy

1H NMR

provides structural information based on the number of signals and its position

1. Each group of chemically equivalent protons gives rise to a signal.
2. positions of the signals in an NMR spectrum are based on how far they are from the signal of the reference compound.
3. This gives us the kind of proton that is responsible for the signal