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The vibronic spectroscopy and IVR dynamics in the $S1$ state of jet-cooled hydroquinone, p-methoxyphenol, and p-dimethoxybenzene have been studied using laser induced fluorescence technique. The objective was to study the effect of stepwise methyl substitution of phenolic hydrogen on the quinoidal character and IVR process in the $S1$ state of hydroquinone. The excitation spectra shows that all the three compounds exist as cis and trans isomers. Hole-burning spectroscopy was carried out to separate out the transitions belonging to both isomers. The excitation spectra reveals enhanced quinoidal character in case of hydroquinone in the $S1$ state. Single vibronic level fluorescence spectra have been recorded to assist vibrational assignments in $S1$ as well as $S0$ states and to infer IVR in $S1$ state. The onset of IVR in hydroquinone, p-methoxyphenol and p-dimethoxybenzene was observed $\sim 1700cm-1,\sim 850cm-1$, and $\sim 700cm-1$ respectively. Substitution of $-OCH3$ group in the place of -OH group lowers the onset of IVR.