THE ADIABATIC BINDING-ENERGY OF NBAR+

The resonant photodissociation spectrum of supersonically cooled and i solated NbAr+ has been observed in the visible. A vibrational structur e of two electronic transitions, labeled here as the B-X and the b-X, are analyzed. Assignment of the diabatic dissociation limits of the b state (Nb+ (4d(4) (3)G(5)) + Ar (S-1(0))) and the B state (Nb+ (4d(3) 5s P-5(2)) + Ar (S-1(0))), places the adiabatic binding energy of the ground state of NbAr+ at 3106 +/- 10 cm(-1). NbAr+ is only slightly mo re strongly bound (130 cm(-1)) than the isoelectronic VAr+, and more w eakly bound than CoAr+ or NiAr+. Trends in the inductive contribution to the binding of metal ions complexed with argon are presented.