Phosphatidylcholine spin probe
Stearic acid spin probe
O
O
COOH
N
O
O
O
O
O N
O
P O
O
–
N
+
O
O
C
C
Fig. 3.9 Lipid spin probes
Fig. 3.7 Hyperfine
interaction of NO
Nuclear spins of nitrogen
atom (N) have quantum
number of +1, 0 and À1, and
these spins act as electron
spin enhancing, no effect
and reducing in magnetic
field, respectively
Therefore, energy level of
electron spin is separated
into three levels
Fig. 3.8 ESR spectrum of
anisotropic NO radical
Position of resonance
absorption depends on
direction of magnetic field
because of anisotropy of
g-value, and separated
distance depends on
anisotropy of T-tensor
3.6 Magnetic Resonance
37