Experimental determination of dipole moments, hyperfine interactions, and ab initio predictions for PtN

Platinum nitride, PtN, was identified in the supersonic coexpansion of a laser ablation generated platinum vapor and ammonia by laser induced fluorescence spectroscopy. The intense blue band system was assigned as the (0,0) d ⁴Π_1/2-X ²Π_1/2 transition with the determined spectroscopic fine parameters being (in cm ^-1):T₀₀=18586.3608(28), B′=0.4541(7), (p + 2q)″ = 0.1219(15), B′ = 0.4164(7), and (p + 2q)′ = 0.2039(8). The Stark shifts and splitting were analyzed to produce ground and excited electronic state values for the permanent electric dipole moment of 1.977(7)D and 1.0(1)D, respectively. The splitting in the field free spectrum for the ¹⁹⁵Pt isotopomer was analyzed to produce magnetic hyperfine parameters (in cm^-1) h_1/2″ = 0.0639(30), h _1/2′ = 0.1571(36), d′ = -0.0979(7), and d″ = -0.0034(15). A sophisticated ab initio calculation of the physical properties of the low-lying states was performed. The experimental results are generally consistent with the ab initio predictions that the band system is the (0,0) d ⁴Π_1/2-X ²Π_1/2 transition. A discussion of the nature of the electronic states is given.