ABSTRACT
Two new electronic transition systems, namely, the [14.0](2)Phi(7/2)-Chi (2)Delta(5/2) and the [15.7](2)Phi(5/2)-Chi (2)Delta(5/2) transitions were observed and analyzed using laser vaporization/reaction supersonic free jet expansion and high resolution laser induced fluorescence spectroscopy. In addition, the (v, 0) bands with v=6-10 of the [14.6](2)Delta(5/2)-Chi (2)Delta(5/2) transition were found to be perturbed by the [15.7](2)Phi(5/2) state. The interaction between the [14.6](2)Delta(5/2) and the [15.7](2)Phi(5/2) states is evident in the progressive increase in hyperfine width of rotational lines of the [14.6](2)Delta(5/2)-X (2)Delta(5/2) transition as the vibrational quantum number increases. Deperturbation procedures were successfully applied to analyze the interaction between these two states. All observed spectra show partially resolved hyperfine structure, and the hyperfine width decreases rapidly as J increases suggested that the hyperfine structure conforms to the Hund's case a(beta) coupling scheme. Accurate molecular and hyperfine constants for the [14.0](2)Phi(7/2), the [14.6](2)Delta(5/2) and the [15.7](2)Phi(5/2) states were obtained and analyzed.
ABSTRACT
High resolution laser induced fluorescence spectrum of IrB in the spectral region between 545 and 610 nm has been recorded and analyzed. Reacting laser-ablated iridium atoms with 1% B(2)H(6) seeded in argon produced the IrB molecule. This is the first experimental observation of the IrB molecule. Four vibronic transition bands, (v,0) with v=0-3 of an electronic transition system, have been observed. Spectra of all four isotopic molecules, (191)Ir(10)B, (193)Ir(10)B, (191)Ir(11)B, and (193)Ir(11)B, were recorded. Isotopic relationships confirmed the carrier of the spectra and the vibrational quantum number assignment. Preliminary analysis of rotational lines showed that these vibronic bands are with Omega' = 2 and Omega" = 3. The electronic transition identified is assigned as the [16.5](3)Pi(2)-X(3)Delta(3) system. Partially resolved hyperfine structure which conforms to the Hund's case a(beta) coupling scheme has been observed and analyzed. The bond length r(0) of the lower X(3)Delta(3) state of IrB was determined to be 1.7675 A.
ABSTRACT
Laser induced fluorescence spectrum of NiBr in the visible region between 604 and 666 nm has been recorded and analyzed. Fourteen bands belonging to three electronic transition systems, namely, [15.1] (2)Delta(52)-X (2)Pi(32), [15.1] (2)Pi(32)-X (2)Pi(32), and [14.0] (2)Delta(52)-X (2)Pi(32) have been observed. Spectra of isotopic molecules were also observed and analyzed. Detailed analysis of the recorded spectra indicated that the two electronic states [15.1] (2)Pi(32) and [15.1] (2)Delta(52) lie about 1 cm(-1) apart from each other and J-dependent perturbation due to spin-uncoupling interaction has been observed. Least squares fitting procedures involving deperturbation matrix elements were used to fit the observed line positions, which yielded accurate molecular constants for the [15.1] (2)Pi(32) and [15.1] (2)Delta(52) states. In addition, the (1,0) band of the [15.1] (2)Delta(52)-X (2)Pi(32) transition shows partially resolved hyperfine structure that was caused by the interaction of unpaired electron with the magnetic moment of the Br nucleus (nuclear spin of I=32) in the excited state. The rapid decrease in hyperfine width as J increases suggests that the hyperfine coupling in the excited state conforms to Hund's case (a(beta)) coupling scheme.
