In this work, we report on the high-resolution infrared spectrum of CCH$^+$ ($^3Π$) recorded in the range $3066-3184$~cm$^{-1}$ by means of leak-out spectroscopy. This spectral range covers the fundamental of the CH stretching mode and a highly excited bending vibrational mode. Based on this data (385 ro-vibrational lines), accurate spectroscopic descriptions of the ground and the two vibrationally excited states of CCH$^+$ were obtained. Besides the band origins, spin-orbit coupling constants, rotational constants, centrifugal distortion constants and $Λ$-doubling constants for the ground and excited vibrational states have been derived. This effective Hamiltonian analysis allowed a search for pure rotational lines of CCH$^+$ in its electronic and vibrational ground state using a two-color millimeterwave - infrared scheme. We observed all rotational transitions from $J^{\prime\prime} = 2$ up to $J^{\prime\prime} = 6$ within the $Ω= 2$ lowest energy fine structure component with resolved hyperfine splittings. This data has already guided the first detection of CCH$^+$ in space toward the Orion Bar photo-dissociation region, and has the potential to support further astronomical searches for CCH$^+$ either through radio or infrared spectroscopy, for example with the James Webb Space Telescope.
Experimental proof of strong $Π$-$Σ$ mixing in the Renner-Teller and Pseudo-Jahn-Teller affected CCH$^+$ ($^3Π$) ion
HFML-FELIX;Center for Astrophysics, Harvard and Smithsonian(哈佛-史密森尼天体物理中心);University of Florida(佛罗里达大学);Institute for Molecules and Materials(分子与材料研究所)
A rotational and vibrational investigation of phenylpropiolonitrile (C$_6$H$_5$C$_3$N)
TMC-1无星云核中存在苯甲腈(C $_6$ H $_5$ CN})的证据使得对其他芳香腈及其环链衍生物的高分辨率研究特别及时。一种这样的物质是苯基丙腈(3-苯基-2-丙炔腈,C $_6$ H $_5$ C $_3$ N),其光谱特性在此首次报道。用傅里叶变换干涉仪在远红外和中红外波长(50 - 3500 cm $^{-1}$)下记录了C $_6$ H $_5$ C $_3$ N}的低分辨率(0.5 cm $^{-1}$)振动光谱,并对14个基本振动谱带的谱带中心进行了归属。用啁啾脉冲傅里叶变换微波(FTMW)谱仪(6 - 18 GHz)、腔增强FTMW仪器(6 - 20 GHz)和毫米波仪器(75 - 100 GHz,140 - 214 GHz)研究了这些物质的纯转动谱。通过对6200多条谱线的归属,我们得到了精确的基态光谱常数(旋转、离心畸变、旋光和核四极超精细常数),并通过计算对较弱的谱带进行了合理的预测。星际搜索这种高度极性的物种,现在可以进行信心,因为天文学上最有趣的无线电线已经测量或可以计算到非常高的精度低于300千兆赫。
First-principles approach to rotational-vibrational frequencies and infrared intensity for H$_2$ adsorbed in nanoporous materials
利用van der Waals密度泛函理论计算了H $_2$在金属-有机骨架中的吸附位和低转动振动能级.由于键拉伸的诱导偶极子被发现准确地给出了第一性原理驱动的近似使用最大本地化的Wannier函数分析。RV跃迁的复杂光谱中的谱线的强度和位置与实验合理地一致,特别是解释了实验中神秘地丢失的仲氢的主要谱线。
Rotational energy levels in the ground vibrational state of methane with kHz-level accuracy from comb-referenced double-resonance and Lamb-dip spectroscopies
Umeå University(于默奥大学);National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology(日本国家计量院,先进产业科学技术研究所);Keio University(庆应义塾大学);University of Virginia(弗吉尼亚大学)
Rotational spectroscopy of the thioformaldehyde isotopologues H$_2$CS and H$_2$C$^{34}$S in four interacting excited vibrational states and an account on the rotational spectrum of thioketene, H$_2$CCS
Leveraging MMW-MMW Double Resonance Spectroscopy to Understand the Pure Rotational Spectrum of Glycidaldehyde and 17 of Its Vibrationally Excited States
Ab initio effective rotational and rovibrational Hamiltonians for non-rigid systems via curvilinear second order vibrational Møller-Plesset perturbation theory
本文提出了一种微扰方法用于刚性和非刚性分子转动和振转有效哈密顿量的从头计算。我们的方法是基于二阶振动Møller-Plesset微扰理论(VMP 2)的曲线实现,通过二阶接触变换扩展到包括旋转效应。虽然更昂贵,这种方法是显着更准确的比标准的二阶振动微扰理论(VPT 2)的系统,很难描述为零阶的直线正常模式谐振子。我们应用这种方法,并证明其准确性的两个分子:硅$_2$ C,一个准线性三原子具有显着的弯曲非谐性,CH $_3$ NO $_2$,其中包含一个完全不受阻碍的甲基转子。除了这两个例子,我们讨论了几个关键的技术方面的方法,包括一个有效的实现Eckart和准Eckart框架嵌入,不依赖于数值有限差分。
Rotational excitation of molecules in the regime of strong ro-vibrational coupling: Comparison between an optical centrifuge and a transform-limited pulse
Universidad de Granada(格拉纳达大学);The University of British Columbia(不列颠哥伦比亚大学);Freie Universität Berlin(柏林自由大学);Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada(格拉纳达大学卡洛斯一世理论与计算物理研究所)
High-Resolution Infrared Spectroscopy and ASAP Analysis of Cyclopentadiene: The Vibrational Modes below 860 cm$^{-1}$ and the $ν_{21}$ Mode at 961 cm$^{-1}$
I. Physikalisches Institut, Universität zu Köln(科隆大学第一物理研究所);Institut des Sciences Moleculaires d’Orsay, Université Paris Saclay(奥赛分子科学研究所,巴黎萨克雷大学);Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes), UMR 6251(雷恩大学,法国国家科学研究中心,雷恩物理研究所);Scuola Superiore Meridionale(南方高等学院);Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna(博洛纳大学贾科莫·恰米西安化学系);Univ. Rennes, Ecole Nationale Supérieure de Chimie de Rennes, ISCR-UMR 6226(雷恩大学,雷恩国立高等化学学院);The Center for Astrochemical Studies, Max-Planck-Institut für extraterrestrische Physik(麦克斯·普朗克地外物理研究所天体化学研究分中心);AILES Beamline, Synchrotron SOLEIL(SOLEIL同步辐射装置AILES光束线)
Algebraic Determination of Spectral Characteristics of Rovibrational States of Diatomic Molecules. II. Analysis of the Vibration-Rotation Interaction by Means of the Factorization Method
Spectroscopic Constants and Vibrational Frequencies for l-C3H+ and Isotopologues from Highly-Accurate Quartic Force Fields: The Detection of l-C3H+ in the Horsehead Nebula PDR Questioned
High-resolution infrared action spectroscopy of the fundamental vibrational band of CN+
利用低温离子阱装置和作用光谱法首次观察到了$^{12}$ C $^{14}$ N $^+$和$^{12}$ C $^{15}$ N $^+$阳离子的基振动模的转动-振动跃迁。测量了$^{12}$ C $^{14}$ N $^+$的谱线P(3)至R(3)和$^{12}$ C $^{15}$ N $^+$的谱线R(1)至R(3),这受到约4 K的陷阱温度和有限的红外激光调谐范围的限制。给出了两种同位素体的光谱参数,谱带起源分别为2000.7587(1)和1970.321(1)cm $^{-1}$,以及结合新数据和文献数据的同位素独立拟合。
Rotational spectroscopy as a tool to investigate interactions between vibrational polyads in symmetric top molecules: low-lying states $v_8 \le 2$ of methyl cyanide, CH$_3$CN
IR photofragmentation of the Phenyl Cation: Spectroscopy and Fragmentation Pathways
我们提出了气相红外光谱的苯基阳离子,phenylium,在其perprotio C $_6$ H $_5^+$和perdeutero C $_6$ D $_5^+$的形式,在260-1925厘米$^{-1}$(5.2-38 $μ$ m)的光谱范围内,并调查观察到的光致碎裂。使用位于自由电子激光器FELICE(腔内实验用自由电子激光器)腔内的傅里叶变换离子回旋共振质谱仪(FTICR MS)内的红外多光子解离(IRMPD)光谱获得光谱和碎片数据。通过将观察到的IR光谱与DFT计算进行比较,使用谐波和非谐波频率计算,确定苯基离子的$^1$ A $_1$单线态性质。为了研究观察到的主要[2C,nH](n=2-4)片段的损失,我们探索了势能面(PES),以解开可能的异构化和断裂反应途径。碎片化的最低能量途径包括直接H消除,以及简易开环机制($\leq2.4$ eV)的组合,随后是H或CCH $_2$的消除。能量上,找到的所有H损耗信道比CCH $_2$损耗信道更容易访问。各种中间体的振动态密度的计算表明,在高内能下,开环是最有利的,消除了直接H-损失作为一个竞争过程。观察到的主要是[2C,2 H]的损失可以通过熵计算来解释,熵计算显示在较高的内能下[2C,2 H]的有利损失。
Theoretical treatment of Coriolis effect using hyper-spherical coordinates, with application to the ro-vibrational spectrum of ozone
用超球坐标对三原子分子的转动和振动相互作用进行了比较和分析。这些方法的不同之处在于z轴的选择和分子的长球形或扁球形转子形状的假设。对于每种情况,块结构的旋转振动的哈密顿矩阵推导和分析,并明确了每种方法的优点和缺点。然后,这个理论被用来计算单取代臭氧的振转光谱,粗略地说,600振动态的16 O 18 O 16 O和16 O 16 O 18 O异构体相结合,与旋转激发高达J=5和两个反转宇称(21600耦合振转态总数)。计算和分析了不同宇称态之间的分裂,即所谓的K-双态。不对称顶部转子项和科里奥利耦合项的作用分别确定,它被发现,它们都影响这些分裂,但在相反的方向。因此,这两种效应部分抵消,并且剩余分裂相对较小。在这项工作中报道的16 O 18 O 16 O和16 O 16 O 18 O的振转态能量与文献(可用于低振动激发)非常一致。这里获得的高激发振动态的新数据,使第一个系统的研究科里奥利效应的对称和不对称同位素的臭氧。
Theoretical vibrational-excitation cross sections and rate coefficients for electron-impact resonant collisions involving rovibrationally excited N2 and NO molecules
Electron-impact vi->vf vibrational excitations cross sections , involving rovibrationally excited N_{2} ( v_{i} , J) and NO( v_{i} , J) molecules (fixed J), are calculated for collisions occurring through the nitrogen resonant electronic state N_{2} ^{-} (X ^{2}Π_{g}), and the three resonant states of nitric oxide NO^{-}(^{3}Σ^{-},^{1} Δ,^{1} Σ^{+}). Complete sets of cross sections have been obtained for all possible transitions involving 68 vibrational levels of N2(X ^{1}Σ^{+}_{g}) and 55 levels of NO(X ^{2}Π), for the incident electron energy between 0.1 and 10 eV. In order to study the rota…
Observation of b$_2$ symmetry vibrational levels of the SO$_2$ $\tilde{\mbox{C}}$ $^1$B$_2$ state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants
SO $_2$的$\mathrm{\tilde{C}}$ $^1$ B $_2$态在反对称伸缩坐标下具有双极小势,使得最小能量几何具有不等价的SO键长.然而,低位的反对称拉伸(b $_2$振动对称性)的奇数量子的水平以前没有被观察到,因为从$\mathrm{\tilde{X}}$状态的零点水平到这些水平的跃迁是振动禁止的。我们用红外-紫外双共振方法观察了$\mathrm{\tilde{C}}$态在1600 cm $^{-1}$以下的b $_2$振动能级。这使得能够直接表征由双最小势导致的振动能级交错。此外,它使我们能够解扰强$c$轴Coriolis相互作用之间的水平的$_1$和b $_2$振动对称性,并准确地确定振动依赖的旋转常数在扭曲的$\mathrm{\tilde{C}}$电子状态。
Quantum mechanical study of the high-temperature $\mathrm{H}^+ + \mathrm{HD} \to \mathrm{D}^+ + \mathrm{H}_2$ reaction for the primordial universe chemistry
Rotational spectroscopy with an optical centrifuge
我们展示了一种新的光谱方法,用于研究具有极宽角动量范围的分子中的电子跃迁。我们采用光学离心机在$^{16}$ O $_2$的基态电子态中产生窄的旋转波包。利用共振增强多光子电离技术,我们记录了氧分子$X^3Σ_{g}^{-}$和$C^3Π_{g}$电子流形之间的多振转跃迁光谱。直接控制旋转激发,延伸到高达$N\gtrsim 120$的旋转量子数,使我们能够解释的复杂结构的旋转光谱的$C^3Π_{g}$超出热可及的水平。
Two-Photon Spectroscopy of the NaLi Triplet Ground State
我们利用双光子光谱研究了$^{23}$ Na $^{6}$ Li分子的三重态基态势($a^3Σ^+$)的振动态.在超冷混合物中的Na和Li原子对被光缔合成激发的三重态分子,其又被耦合到三重态地电位的振动态。振动态结合能,线强度,和潜在的三重地面$a^3Σ^+$潜在的拟合参数的报告。我们还观察到最低振动态的转动分裂。