NMR Spectroscopy Flashcards
What does NMR stand for
Nuclear magnetic resonance
What do the 2 different types of NMR measure?
Position of 13C
Position of 1H
What is one advantage of Carbon NMR over Hydrogen NMR
13C NMR gives simpler spectra than 1H NMR.
What is chemical shift? What is it compared to? On what scale is it recorded?
The resonant frequency of nuclei compared to TMS
The delta Scale in ppm in parts per millon
How do you get the ratio of H atoms from an NMR
The relative heights of the peaks
What are HNMR samples dissolved in?
CCl4
Deutarated solvents - group of compounds where hydrogen atoms are substituted by deuterium atoms. (D2O)
What is the standard used in NMR
TMS (Tetramethysilane)
Why is TMS used as a baseline in NMR
It is inert, non-toxic, and easy to remove from the sample.
What is the N+1 rule in HNMR
N hydrogens on an adjacent carbon atom will split a peak into n + 1 smaller peaks.
When does spin-spin coupling occur?
Neighbouring hydrogen atoms (3 or fewer bonds away, or on the adjacent carbon) affect the magnetic field of ‘H atoms and causes their peaks to split
What is the integration trace?
A stepped line that makes it easier to measure
the area under the curve (height of line = area
under that peak)
How does CO2 cause global warming
Its bonds absorb infrared radiation
IR radiation emitted by the earth does not escape
