T22 and linewidth Due to the characteristics of FT, the linewidth depends on the decay rate of the FID (for the linewidth at half-height) The FId being a composed of exponentially decaying sine and cosine signals, eq [2-12] should read M-y(t=M-ycos(ot)+ Mxsin(ot))exp(t/T2) Chemical shift Resonance frequencies of the same isotopes in different molecular surroundings differ by several ppm(parts per million). For resonance fr 100 MHz range these differences can be up to a few 1000 Hz. After creating a Mx,y coherence, each spin rotates with its own specific resonance frequency o, slightly different from the Bi transmitter(and receiver) frequency (o. In the rotating coordinate system, this corresponds to a rotation with an offset frequency Q2=@-0o time domain frequency domain13 T2 and linewidth Due to the characteristics of FT, the linewidth depends on the decay rate of the FID: lw1/2 = 1 pT2 [2-15] (for the linewidth at half-height) The FID being a composed of exponentially decaying sine and cosine signals, eq. [2-12] should read M-y(t) = {M-ycos(wt) + Mx sin(wt)}exp(-t/T2 ) [2-16] Chemical Shift Resonance freuquencies of the same isotopes in different molecular surroundings differ by several ppm (parts per million). For resonance frequencies in the 100 MHz range these differences can be up to a few 1000 Hz. After creating a Mx,y coherence, each spin rotates with its own specific resonance frequency w, slightly different from the B1 transmitter (and receiver) frequency w0. In the rotating coordinate system, this corresponds to a rotation with an offset frequency W = w - w0 . time domain frequency domain