$\mathrm{[(\eta^{3}\text{-}C_3H_5)Mn(CO)_4]}$ shows fluxional behavior. The 'H NMR spectrum of this compound when it is in the non-fluxional state shows-
(a)one signal
(b)two signals in the intensity ratio of $4:1$
(c)three signals in the intensity ratio of $2: 2: 1$
(d)five signals of equal intensity.
Answer
Answer (as printed): C
Explanation
$H_c$ = central proton$H_a$ = is anti with respect to $H_c$$H_s$ = syn with respect to $H_c$$H_a$, $H_s$, $H_c$ environment are different, new intensity ratio 2:2:1.When allyl is non-fluxional.