[(η3 - C3H5) Mn(CO)4] shows fluxional behaviour. The 1H NMR spectrum of this compound when it is in the non-fluxional state shows
1
one signal
2
two signals in the intensity ratio of 4 ∶ 1
3
three signals in the intensity ratio of 2 ∶ 2 ∶ 1
4
five signals of equal intensity