Knowledge Bank

The wavelength-resolved fluorescence excitation technique has been used to record the (2,0) band of the $C3\Delta 3-a1\Delta$ transition and the (2,3) and (2,4) bands of the $C3\Delta 3-X3\Delta 3$ electronic transition of TiO at a resolution of $0.03cm-1$. These data were combined with previous high-resolution analysis of the ground $X3\Delta state1$ to obtain accurate term energies for the singlet states manifold of TiO. The term energy for the first excited $a1\Delta$ state above the (nonexistent) J=0 level of the $X3\Delta 1$ ground state is: $T0(a1\Delta )=3444.367\pm 0.020cm-1$. This value differs significantly from the previously derived $value2$ of $T0(a1\Delta )=3448.33\pm 0.04cm-1$. Energy values are lesser by about $4cm-1$ than currently accepted $values3$ for the singlet states of TiO. The principal constants (in $cm-1$) obtained from recent and previous analyses are: $StatevTvBvDv107e1\Sigma +029960.592(14)0.48825(3)5.10(12)f1\Delta 022513.355(4)0.502363(6)6.671(30)c1\Phi 021284.957(4)0.521366(15)3.16(13)b1\Pi 014717.185(3)0.511995(6)e6.409(25)0.512154(6)f6.425(26)C3\Delta 2221176.502(3)0.489124(10)6.913d1\Sigma +05663.147(4)0.547702(7)6.3813(26)a1\Delta 03444.367(1)0.536287(4)6.107(29)$ Work supported by AFOSR under grants F19628-90-C-025 and F49620-92-J-0215.