Laser-induced fluorescence and Optical/Stark spectroscopy of PtC

Optical/Stark measurements have been performed on the (0,0) bands of both t he A(') (1)Sigma(+)-X (1)Sigma(+) system (nu(0)approximate to 12 643 cm(-1) ) and the A(') (1)Pi-X Sigma(+) system (nu(0)approximate to 13 196 cm(-1)) of platinum monocarbide. The PtC molecules were produced in a pulsed supers onic molecular beam source following the reaction of laser ablated platinum vapor with a mixture of a few percent of methane in argon. The newly deter mined permanent electric dipole moments obtained are 1.94(2)D (A" (1)Sigma( +)) and 1.919(9)D (A' (1)Pi). These results are discussed in terms of a pro posed molecular orbital correlation diagram for platinum containing diatomi cs. The laser-induced fluorescence spectrum of the (0,0)A(') (1)Sigma(+)-X (1)Sigma(+) transition of PtC has been re-recorded at high resolution (full width of half-maximum similar to 40 MHz) and analyzed to yield rotational constants for the four most abundant isotopomers of PtC, extending the prev ious analysis [Appelblad, Nilsson, and Scullman, Phys. Scr. 7, 65 (1973)]. The anomalously large value (similar to 15 MHz) for the newly derived nucle ar-spin rotation parameter, C-I(Pt-195), for the A" (1)Sigma(+) state is di scussed. (C) 1999 American Institute of Physics. [S0021-9606(99)01447-6].