RESONANT 2-PHOTON IONIZATION SPECTROSCOPY OF JET-COOLED NIPT

Resonant two-photon ionization spectroscopy of jet-cooled NiPt has been used to investigate the possibility of d-electron contributions to the bonding in this species. Based on an abrupt onset of predissociation, the bond strength of NiPt is assigned as D0 (NiPt) = 2.798 ± 0.003 eV. Comparisons of scans using ArF (6.42 eV) or F2 (7.87 eV) radiation as the ionization laser yield IP(NiPt) = 8.02 ± 0.15 eV, from which we derive D0 (Ni+-Pt) = 2.41 ± 0.15 eV and D 0 (Ni-Pt+) = 3.58 ± 0.35 eV. High resolution studies of the 6-0 and 8-0 bands of one of the three identifiable progressions demonstrate an Ω′ = 0←Ω″ = 0 transition with r′e = 2.3396 ± 0.0039 Å and r″0 = 2.2078 ± 0.0023 Å. The short bond length and large bond strength of NiPt, as compared to the corresponding values (re = 2.330 ± 0.003 Å and D0 = 2.34 ± 0.10 eV) for the coinage metal analog, CuAu, demonstrate significant d-orbital contributions to the bonding in NiPt. © 1990 American Institute of Physics.