THE ALPHA-1-SIGMA+[-CHI-1-SIGMA+ BAND SYSTEM OF CRMO

The 4870 angstrom band system of jet-cooled CrMo has been rotationally resolved and assigned as A 1-SIGMA+<--X 1-SIGMA+. The band system is clearly analogous to the 4597 angstrom band system of Cr2 and the 5180 angstrom band system of Mo2. As in the Cr2 and Mo2 systems, the upper state possesses a very fluorescence lifetime, which has been measured as 14.7 +/- 0.3 ns. The bond lengths of the ground and excited states are r(e)(X 1-SIGMA+) = 1.8182 +/- 0.0015 angstrom and r(e)(A 1-SIGMA+) = 1.8264 +/- 0.0014 angstrom, respectively. These results clearly establish that CrMo, like Cr2 and Mo2, possesses multiple d electron bonds in its ground (X 1-SIGMA+) and excited (A 1-SIGMA+) electronic states.