10. Spectroscopy Flashcards
as you move from Red to violet what happens to the wavelength and frequency
wavelength decreases
frequency increases
what is the wavelength equation
wavelength = speed of light / frequency
single bonds appear on what side of the spectrum
right side
what are the wavenumbers that single bonds appear in
<1500
double bonds appear from what wavenumbers
1600-1850
triple bonds appear at what wavenumbers
2100-2300
the left side of the spectrum contains signals produced from what bonds
X-H bonds (eg C-H, O-H)
bonds that have a stronger dipole moment will produce what kind of signal
higher intensity signal than weaker dipole moment
if a compound is symmetrical what signal is produced
no signal
what does the location of each signal indicate in NMR
number of different kinds/electronic environments protons are in
environment of protons that give rise to signals
what does the area under each signal indicate in NMR
number of protons giving rise to the signal
what does the shape of each signal indicate in NMR
number of neighboring protons
protons in the same environment are
chemically equivalent
two protons will be chemically equivalent if they can be what
interchanged by rotation oe reflection
two protons will be chemically equivalent if they can be what
interchanged by rotation or reflection
how many signals will show up for the 3 protons of a CH3 group
one signal
chemically equivalent
if there are no chiral carbons will the 2 protons of the CH2 group be chemically equivalent
yes
if there are chiral carbons will the 2 protons of the CH2 group be chemically equivalent
no produces separate signals
if 2 CH2 groups can be interchanged by reflection or rotation are they equivalent
yes produces one signal
what is the chemical shift
relative to freq of absorption of reference compound TMS
what is intergration
area under each signal
what is multiplicity
number of peaks in each signal
if n is the number of neighboring protons then what will be the equation to find the multiplicity
n + 1
what is considered neighboring protons
if 2 or 3 sigma bonds separate them
