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We report optical double resonance (ODR) experiments in which selective preparation of gas-phase acctylene $(C2H2)$ in discrete rotational state of the $V2=1(C=Cstretch,1974cm-1)$ vibrational level is achieved by pulsed conherent Raman excitation, with laser-induced flourescence (LIF) detection.1 The quality of these LIF-detected Raman-ODR spectra is superior to that attained in our previous work on larger polyatomic $molecules2$. The method depends on a careful choice of the vibronic bands used to monitor the $V2$-mode Raman excitation, since the $A~\leftarrow X~$ absorption system of $C2H2$ involves a bent-linear geometric transition and the Franck-Condon principle favours quanta of the symmetric bending modes ($V3$ in the $X~$ state and $V4$ in the $X~$ state). Several previously unreported $A~\leftarrow A~$ vibronic bands have been recorded with the intensity-enhancement of $V2$-mode Raman excitation: $21031\mathrm{<mrow\; data-mjx-texclass="ORD">0</mrow>}(242nm),20\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}32\mathrm{<mrow\; data-mjx-texclass="ORD">0</mrow>}(236nm),20\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}33\mathrm{<mrow\; data-mjx-texclass="ORD">0</mrow>}(231nm),20\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}31\mathrm{<mrow\; data-mjx-texclass="ORD">0</mrow>}40\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}(246nm)$ and $20\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}32\mathrm{<mrow\; data-mjx-texclass="ORD">0</mrow>}40\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}(240nm)$. Our Raman-ODR spectra clearly demonstrate the effect on rovibronic intensities of $‘‘axis-switching″.3$ resolved one rotational state at a time. Variation of the delay between the Raman pump pulses and the LIF probe also provides a view of collision-induced state-to-state- rotational energy transfer. Another Raman-ODR spectroscopic approach yields highly resolved state-specific Raman-excitation frequency through O-,Q- and S-branch rovibrational transitions. Parallel infrared-ultravoiler double resonance and Raman-ODR studies of $C2D2$ and $C2HD$ are also is progress.