Tam W S, Ye Jianjun, Cheung A S-C
Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
J Chem Phys. 2004 Nov 15;121(19):9430-5. doi: 10.1063/1.1806417.
Laser-induced fluorescence spectrum of NiI in the near infrared region of 714-770 nm has been recorded. Seven bands belonging to three electronic transition systems were observed and analyzed: the (0,0), (1,0), and (2,0) bands of [13.3] (2)Sigma(+)-A (2)Pi(3/2) system; the (1,1) and (0,1) bands of [13.9] (2)Pi(3/2)-X (2)Delta(5/2) system; and the (0,0) and (1,0) bands of [13.9] (2)Pi(3/2)-A (2)Pi(3/2) system. Spectra of isotopic molecules confirmed the vibrational quantum number assignment of the observed bands. Least-squares fit of rotationally resolved transition lines yielded accurate molecular constants for the v=0-2 levels of the [13.3] (2)Sigma(+) state, the v=0 level of the A (2)Pi(3/2), and the v=1 level of the X (2)Delta(5/2) state. The vibrational separation, DeltaG(1/2), of the ground state was measured to be 276.674 cm(-1). With the observation of the [13.9] (2)Pi(3/2)-A (2)Pi(3/2) and [13.9] (2)Pi(3/2)-X (2)Delta(5/2) transitions, we accurately determined the energy separation between the A (2)Pi(3/2) and the X (2)Delta(5/2) to be 163.847 cm(-1). This confirms that the order of the A (2)Pi(3/2) and X (2)Delta(5/2) states in NiI is reversed when compared with other nickel monohalides.
记录了NiI在714 - 770 nm近红外区域的激光诱导荧光光谱。观察并分析了属于三个电子跃迁体系的七个谱带：13.3Σ⁺ - A(2)Π³/₂体系的(0,0)、(1,0)和(2,0)谱带；13.9Π³/₂ - X(2)Δ⁵/₂体系的(1,1)和(0,1)谱带；以及13.9Π³/₂ - A(2)Π³/₂体系的(0,0)和(1,0)谱带。同位素分子的光谱证实了所观察谱带的振动量子数归属。对转动分辨的跃迁谱线进行最小二乘法拟合，得到了13.3Σ⁺态v = 0 - 2能级、A(2)Π³/₂态v = 0能级以及X(2)Δ⁵/₂态v = 1能级的精确分子常数。基态的振动间隔ΔG¹/₂测量值为276.674 cm⁻¹。通过观察13.9Π³/₂ - A(2)Π³/₂和13.9Π³/₂ - X(2)Δ⁵/₂跃迁，我们精确确定了A(2)Π³/₂和X(2)Δ⁵/₂之间的能量间隔为163.847 cm⁻¹。这证实了与其他一卤化镍相比，NiI中A(2)Π³/₂和X(2)Δ⁵/₂态的顺序是相反的。
