论文标题
在TMC-1中发现的新质子化分子：HCCNCH+
A new protonated molecule discovered in TMC-1: HCCNCH+
论文作者
论文摘要
近年来，我们发现在冷致密云中检测到的质子化分子数量有所重要。在这里，我们报告了HCCNCH+TMC-1的检测，HCCNC的质子化形式是HC3N的亚稳态异构体。这是在冷致密云中检测到的亚稳态异构体的第一种质子化形式。该检测是基于对Yebes进行的40m和IRAM 30M望远镜进行的观察结果，该望远镜揭示了四个和谐相关的线路。我们得出旋转常数b = 4664.431891 +/- 0.000692 MHz和一个离心失真常数d = 519.14 +/- 4.14 Hz。从对潜在载体的高级筛查中，我们将一系列线系列分配给离子HCCNCH+。对于HCCNCH +，我们得出了（3.0 +/- 0.5）E10 cm-2的列密度，这导致HCCNCH +/HCCNC丰度比为0.010 +/- 0.002。该值通过最先进的化学模型很好地再现，但是，该模型遭受HCCNCH+化学的重要不确定性。 The observational and theoretical status of protonated molecules in cold dense clouds indicate that there exists a global trend in which protonated-to-neutral abundance ratios MH+/M increase with increasing proton affinity of the neutral M, although if one restricts to species M with high proton affinities (>700 kJ/mol), MH+/M ratios fall in the range 0.001-0.1, with no apparent correlation具有质子亲和力。我们建议在不久的将来是在冷致密云中检测的各种质子化分子。
In recent years we have seen an important increase in the number of protonated molecules detected in cold dense clouds. Here we report the detection in TMC-1 of HCCNCH+, the protonated form of HCCNC, which is a metastable isomer of HC3N. This is the first protonated form of a metastable isomer detected in a cold dense cloud. The detection was based on observations carried out with the Yebes 40m and IRAM 30m telescopes, which revealed four harmonically related lines. We derive a rotational constant B = 4664.431891 +/- 0.000692 MHz and a centrifugal distortion constant D = 519.14 +/- 4.14 Hz. From a high-level ab initio screening of potential carriers we confidently assign the series of lines to the ion HCCNCH+. We derive a column density of (3.0 +/- 0.5)e10 cm-2 for HCCNCH+, which results in a HCCNCH+/HCCNC abundance ratio of 0.010 +/- 0.002. This value is well reproduced by a state-of-the-art chemical model, which however is subject to important uncertainties regarding the chemistry of HCCNCH+. The observational and theoretical status of protonated molecules in cold dense clouds indicate that there exists a global trend in which protonated-to-neutral abundance ratios MH+/M increase with increasing proton affinity of the neutral M, although if one restricts to species M with high proton affinities (>700 kJ/mol), MH+/M ratios fall in the range 0.001-0.1, with no apparent correlation with proton affinity. We suggest various protonated molecules that are good candidates for detection in cold dense clouds in the near future.
