Supporting Information for:
Spectroscopy and Dynamics of the Predissociated, Quasi-linear
S2 State of Chlorocarbene
Chong Tao,1 Craig Richmond,2 Calvin Mukarakate,1 Scott H. Kable,2 George Basckay,2 Eric C.
Brown, Richard Dawes,3 Phalgun Lolur,3 and Scott A. Reid1
1
Department of Chemistry, Marquette University, Milwaukee, WI 53201-1881
2
School of Chemistry, University of Sydney, Sydney, Australia NSW 2006
3
Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409
Figure S1: Lowest three 1A' states (S0, S2, and S3) are plotted (solid lines) along the C-H
stretching coordinate with the C-Cl distance and angle fixed (rCCl = 1.6 Å, Theta = 180°). Also
shown (dashed line) is the lowest 3A'' triplet state (T1). The rotated-Davidson correction for
multistate MRCI energies was applied to MRCI energies from the aug-cc-pV(Q+d)Z basis. The
reference for the MRCI calculations was at the full-valence CASSCF level including 27 singletstates (14 1A', 13 1A'') and 18 triplet states (8 3A', 10 3A'') with dynamic weighting.
Notes: The behavior of the singlet states is qualitatively similar to the CHF system, with S3
cutting through S2 and S0. For the collinear geometries shown here, T1 is lower than S0 and S1
(see also Figure 2), but correlating to the same asymptote as does S3 (diabatically). This
asymptote is relatively higher in energy than what is observed in the CHF system.
Figure S2: 2D Plot of lowest 1A' and 1A'' states (S0 and S1, solid color) with C-Cl distance fixed
(rCCl = 1.6 Å). The two singlets are degenerate for collinear geometries (Theta = 180°) forming
a Renner-Teller pair. The lowest 3A'' triplet state (T1, transparent) cuts through S0 not far from
the minimum and is lower than the singlets for collinear geometries.
Notes: The conical intersection seen at Theta = 180° and rCH~1.64 Å is also seen in Figure 1,
where S3 (diabatically) cuts through both S2 and S0. The 1A'' Renner-Teller partner of S3 (S4)
intersects S1, the same way as S3 intersects S0.
Figure S3
2D Plot of S2 state with C-Cl distance fixed (rCCl = 1.6 Å). A sharp kink due to
the intersections noted above is seen for Theta = 180° at rCH = 1.545 Å and rCH
= 1.640 Å. The crossings are avoided at bent geometries with S2 only slightly
perturbed at Theta = 170° and less so at smaller angles.
Figure S4
Optical-optical double resonance spectrum of the (0,71,2) level of the S2 state of
CD35Cl. The spectra show transitions terminating in the final state levels J = 3, 4,
5. A fit to the data using a Gaussian lineshape function is shown.