Rotational Spectra of Three Cyanobutadiene Isomers (C 5 H 5 N) of Relevance to Astrochemistry and Other Harsh Reaction Environments
Rotational Spectra of Three Cyanobutadiene Isomers (C 5 H 5 N) of Relevance to Astrochemistry and Other Harsh Reaction Environments
复制标题
与天体化学和其他恶劣反应环境相关的三种氰基丁二烯异构体（C 5 H 5 N）的旋转光谱
DOI：
10.1021/jacs.1c03777
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发表时间：
2021
影响因子：
15
通讯作者：
McMahon, Robert J.
中科院分区：
文献类型：
--
作者：
Zdanovskaia, Maria A.;Dorman, P. Matisha;Orr, Vanessa L.;Owen, Andrew N.;Kougias, Samuel M.;Esselman, Brian J.;Woods, R. Claude;McMahon, Robert J.
合成了三种氰基丁二烯异构体，并在130-375 GHz频率范围内分析了它们的转动光谱。这些物种是已知星际分子的密切类似物，是杂环芳香分子吡啶（C5 H5 N）的异构体，提供了揭示有关天文环境中化学的重要见解的机会。E-1-氰基-1，3-丁二烯和Z-1-氰基-1，3-丁二烯在转动光谱中出现了三种-变换构象，而4-氰基-1，2-丁二烯则出现了反斜和顺-周平面构象。对于反式-Z-1-氰基-1，3-丁二烯和forsyn-peripanal-4-氰基-1，2-丁二烯，超过1000个跃迁适合于具有低不确定性（<50 kHz）的八次畸变转子哈密顿量。尽管在该频率范围内，反式-E-1-氰基-1，3-丁二烯、去甲反式-斜-4-氰基-1，2-丁二烯都可以用畸变转子哈密顿量完全处理，但我们在此提供了每种物质超过1000个跃迁的最小扰动、单态最小二乘拟合，产生一组光谱常数，预期能够准确预测高-两种异构体在高达370 GHz的频率处的强度跃迁。这些cyanobutadienes指定的转换和光谱常数已经能够识别两个异构体在恶劣的反应环境中，应该足以使他们的识别在天文环境中的射电天文学。
Three cyanobutadiene isomers have been synthesized and their rotational spectra analyzed in the 130–375 GHz frequency range. These species, which are close analogues of known interstellar molecules and are isomers of the heterocyclic aromatic molecule pyridine (C5H5N), offer the opportunity of revealing important insights concerning the chemistry in astronomical environments. Thes-transconformers ofE-1-cyano-1,3-butadiene andZ-1-cyano-1,3-butadiene are observed, while both theanti-clinalandsyn-periplanarconformers of 4-cyano-1,2-butadiene are evident in the rotational spectra. Over 1000 transitions fors-trans-Z-1-cyano-1,3-butadiene and forsyn-periplanar-4-cyano-1,2-butadiene are fit to an octic, distorted-rotor Hamiltonian with low uncertainty (<50 kHz). Although neithers-trans-E-1-cyano-1,3-butadiene noranti-clinal-4-cyano-1,2-butadiene can be fully treated with a distorted-rotor Hamiltonian in this frequency range, we provide herein minimally perturbed, single-state least-squares fits of over 1000 transitions for each species, yielding sets of spectroscopic constants that are expected to enable accurate prediction of high-intensity transitions at frequencies up to 370 GHz for both isomers. The assigned transitions and spectroscopic constants for these cyanobutadienes have already enabled the identification of two isomers in harsh reaction environments and should be sufficient to enable their identification in astronomical environments by radio astronomy.