Term
|
Definition
| nuclei magnetic moments that can either align with the field or against the magnetic field. |
|
|
Term
| what does the alpha state refer to? |
|
Definition
nuclei whose mag moments align with the field.
(alpha= align) |
|
|
Term
| what does the beta state refer to? |
|
Definition
nuclei whose mag moments align against the field.
|
|
|
Term
| alpha vs beta state who has higher energy |
|
Definition
|
|
Term
nmr uses a variable of measurment called______
with units called _____ |
|
Definition
chemical shifts (δ)
units: parts per million (ppm) |
|
|
Term
the chemical shift increases in what direction ,
this is called ____ field |
|
Definition
to the left
(called downfield) |
|
|
Term
NMR usually is on what nuclei (2)
does 12C have magnetic moments? |
|
Definition
1H & 13 C
12 C (does not have magnetic moments) |
|
|
Term
| what does it mean when it says the proton that is being deshielded? |
|
Definition
dieshieled means:
the proton is next to an electronegative atom (which is pulling electron density from the proton) thus deshielding it from its own electron cloud) |
|
|
Term
| protons that are being deshielded would appear more to the left or right? |
|
Definition
more to the left.
(aka more downfield) |
|
|
Term
H-Cl vs H-NH2
would one would appear more to left
include why |
|
Definition
H-Cl : more on the LEFT b/c Cl is electrongetive & e- WITHDRAWING
= proton dishielded
H-NH2: NH2 is an e-donating group
and thus shields the proton
|
|
|
Term
| when does splitting or coupling occur? |
|
Definition
| when 2 protons that are in close proximity but are NOT magentically identical. |
|
|
Term
CH3 -O- CHCl2
would peak would be taller? |
|
Definition
CH3 peak
b/c they are more of these type of protons
(CHCl2 just has 1 proton) |
|
|
Term
| formula for determining multiplets |
|
Definition
n+1
n= of H that are 3 bonds away |
|
|
Term
| area of each peak is determined by |
|
Definition
| ratio of protons producing each peak |
|
|
Term
| any more than 4 peaks is called |
|
Definition
|
|
Term
| give the range for R-CH3 protons |
|
Definition
about 0.9
(most shielded) |
|
|
Term
| give the range for alkyl (triple bond) protons |
|
Definition
|
|
Term
| give the range for alkene (double bond) protons |
|
Definition
|
|
Term
| give the range for aldehydes (double bond) protons |
|
Definition
|
|
Term
| give the range for carboxylic acid (double bond) protons |
|
Definition
|
|
Term
| give NMR shift for aromatic protons |
|
Definition
|
|
Term
| give NMR shift for alcohol protons |
|
Definition
|
|
Term
| give NMR range for vinylic |
|
Definition
|
|
