Rotational spectroscopy of pyridazine and its isotopologs from 235-360 GHz: equilibrium structure and vibrational satellites.
Rotational spectroscopy of pyridazine and its isotopologs from 235-360 GHz: equilibrium structure and vibrational satellites.
复制标题
235-360 GHz 哒嗪及其同位素的旋转光谱：平衡结构和振动卫星。
DOI：
10.1063/1.4832899
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
R. McMahon
中科院分区：
文献类型：
--
作者：
Brian J. Esselman;Brent K Amberger;J. Shutter;Mitchell A Daane;J. Stanton;R. Woods;R. McMahon
哒嗪 (o-C4H4N2)（苯的邻位二取代氮类似物）的旋转光谱已在气相中进行了测量和分析。对于正常同位素的地面振动状态，已在 238 至 360GHz 之间识别出超过 2000 个单独的旋转跃迁，并已拟合到六阶离心畸变哈密顿量的 13 个参数。现在可以从该模型预测该频率区域中的所有转变，其精度接近实验精度，即足以满足未来对该物种的任何射电天文学搜索的目的。已在自然丰度中检测到三种同位素，[3-(13)C]-C4H4N2、[4-(13)C]-C4H4N2 和 [1-(15)N]-C4H4N2，并且已对这些物种中的每一个进行了数百条线的测量，并适合六阶哈密顿量。通过增强的氘取代合成了另外十种同位素异构体，并进行了分析以进行完整的结构测定。哒嗪的平衡结构 (Re) 是通过使用 ANO0 基组的 CCSD(T) 计算预测的相互作用常数校正振动-旋转耦合影响的实验旋转常数并进一步校正电子质量的影响而获得的。最终的 Re 结构参数具有极高的准确性，其能够从 9 个结构参数很好地预测 28 个独立惯性矩（14 个同位素同位素的 Ia 和 Ib）就证明了这一点。已检测到主要同位素的六颗最低能量基本振动卫星的旋转光谱。五颗最低能量振动卫星的旋转光谱已被分配和拟合，以产生准确的旋转和畸变常数，而第六颗卫星的拟合和分配尚未完成。结果发现，所得的振动-旋转相互作用（α）常数与耦合簇计算预测的常数非常一致，这被证明是将卫星频谱明确分配给特定振动模式的关键。
The rotational spectrum of pyridazine (o-C4H4N2), the ortho disubstituted nitrogen analog of benzene, has been measured and analyzed in the gas phase. For the ground vibrational state of the normal isotopolog, over 2000 individual rotational transitions have been identified between 238 and 360 GHz and have been fit to 13 parameters of a 6th-order centrifugal distortion Hamiltonian. All transitions in this frequency region can now be predicted from this model to near experimental accuracy, i.e., well enough for the purpose of any future radio-astronomical search for this species. Three isotopologs, [3-(13)C]-C4H4N2, [4-(13)C]-C4H4N2, and [1-(15)N]-C4H4N2, have been detected in natural abundance, and several hundred lines have been measured for each of these species and fit to 6th-order Hamiltonians. Ten additional isotopologs were synthesized with enhanced deuterium substitution and analyzed to allow for a complete structure determination. The equilibrium structure (Re) of pyridazine was obtained by correcting the experimental rotational constants for the effects of vibration-rotation coupling using interaction constants predicted from CCSD(T) calculations with an ANO0 basis set and further correcting for the effect of electron mass. The final Re structural parameters are determined with excellent accuracy, as evidenced by their ability to predict 28 independent moments of inertia (Ia and Ib for 14 isotopologs) very well from 9 structural parameters. The rotational spectra of the six lowest-energy fundamental vibrational satellites of the main isotopolog have been detected. The rotational spectra of the five lowest-energy vibrational satellites have been assigned and fit to yield accurate rotational and distortion constants, while the fit and assignment for the sixth is less complete. The resultant vibration-rotation interaction (α) constants are found to be in excellent agreement with ones predicted from coupled-cluster calculations, which proved to be the key to unambiguous assignment of the satellite spectra to specific vibration modes.
影响因子：
15
作者：
Do, Hien-Ouang;Khan, Rana M. Kashif;Daugulis, Olafs
通讯作者：
Daugulis, Olafs