Spectroscopy of jet-cooled AlY

Pulsed laser ablation of a 1:1 Al:Y alloy in the throat of a pulsed supersonic beam of helium or argon has been used to produce jet cooled diatomic AlY for study by resonant two photon ionization spectroscopy. A band system of AlY at 9500 cm exp -1 has been rotationally analyzed as an Omega '=0 < - Omega ''=0 transition and this is thought to correspond to a [9.5] exp 3 Sigma exp - sub 0 < -X exp 3 Sigma exp - sub 0 band system. The bond lengths of the ground and excited states are r exp '' sub 0 (X exp 3 Sigma exp - sub 0 )=2.8728plus/minus0.0012 A and r exp ' sub e ([9.5] exp 3 Sigma exp - sub 0 )=2.83plus/minus0.03 A, respectively. The chemical bonding in AlY is discussed and compared with the bonding in its cation, AlY exp + and in Al sub 2 .