Spectroscopic Methods - Absorption Spectra Flashcards
Why do we need to carry out structural analysis?
Because we need to identify and characterise compounds with a high degree of confidence.
Briefly, what is absorption spectra?
Is the measurement of interaction between molecules, ions, or atoms and electromagnetic radiation.
Briefly, what is U.Vis Spectroscopy?
Identifies chromophoric groups, and provides information about organic compounds with conjugated double bonds.
What is infrared used for?
To identify functional groups and unique comparison with authentic sample from fingerprint region.
Briefly, what is the basis of IR spectroscopy?
The absorption of IR radiation and higly specific frequencies resulting in the furthering of vibration/ movement of a bond/ between two atoms.
What is NMR used for? (H context)
Provides number of protons, proton environments etc.
Briefly, what is the basis of NMR?
In a molecule, different hydrogens experience different levels of shielding and therefore severity of the magnetic field. We can measure the changes.
What is the relationship between the population of an energy level, and the energy level?
The bigger the energy difference, the bigger the population difference, and vice versa.
What can the energy of the wave be defined by?
Wavelength, wavenumber, frequency and delta of occasion (NMR).
In terms of spectrometers, what is a continuous wave?
Involves irradiating the sample by sweeping/scanning through the entire wavelength range.
In terms of spectrometers, what is a Fourier transform?
The sample is irradiated by all wavelengths/ frequencies all at once. Carries out conversions from the time, to frequency domain. Much more sensitive.
