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Development of multidimensional mass spectrometry combined with laser photodissociation spectroscopy

多维质谱结合激光光解离光谱的发展

基本信息

批准号：
10554028
负责人：
MIKAMI Naohiko
金额：
$ 7.55万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10554028/
关键词：
Laser spectroscopy of mass-selected molecular ions Ion trap method Cluster structure Vibrational spectroscopy of molecular ions Intramolecular hydrogen bond クラスターサイズ選別振動分光水素結合クラスターナフトール 2・ピリドン互変異性イオン種の新振動分光法 O・クレゾール

项目摘要

We have developed a new equipment for spectroscopic measurements of size-selected molecular cluster ions, as well as molecular fragment ions. The setup consists of a supersonic molecular beam source, and ionization section, a Q-pole mass filter for size-selection, an ion trap cell combined with laser photodissociation section, and a second Q-pole mass analyzer with a ion detector. With this setup, spectroscopic measurements for electronic and vibrational transitions of cations can be performed.Major results at the present stage of the project are the following :1. A new infrared (IR) spectroscopic technique for jet-cooled molecular cations is developed. The method involves two-color laser excitation via neural excited state to high Rydberg states, vibrational excitation of its ion core with IR light, and vibrational autoionization of the ion core. It has been applied for the several compounds ;(1) Observation of OH stretching vibrations of substituted phenol cations to investigate intramolecular hydrogen bonds in ionic states.(2) Observation of CH stretching vibrations of aromatic hydrocarbon cations to study the inaccessible vibrational levels with conventional methods.2. IR-UV double resonance spectroscopy of size-selected molecular clusters is established for the investigation of their intermolecular binding structures in combination with ab initio quantum mechanical calculations.(1) Vibrational spectroscopy and cluster structures of 2-pyridone and its clusters.(2) Structure and vibrational relaxation of benzonitril clusters with various molecules.(3) Structural investigations of benzyl alcohol rotomers and of its water solvated clusters.

我们开发了一种新的设备，用于光谱测量大小选择的分子簇离子，以及分子片段离子。该装置由一个超音速分子束源和电离区、一个用于尺寸选择的q极质量过滤器、一个结合激光光解离区的离子阱电池和一个带离子检测器的第二个q极质量分析仪组成。利用这种装置，可以对阳离子的电子和振动跃迁进行光谱测量。本项目现阶段取得的主要成果如下：提出了一种新的喷气冷却分子阳离子红外光谱技术。该方法包括双色激光通过神经激发态激发到高里德伯态，用红外光振动激发其离子核，以及离子核的振动自电离。它已应用于几种化合物；(1)观察取代苯酚阳离子的OH伸缩振动，研究离子态分子内氢键。(2)观察芳烃阳离子的CH伸缩振动，研究常规方法无法达到的振动能级。结合从头算量子力学计算，建立了大小选择分子簇的红外-紫外双共振光谱，用于研究其分子间结合结构。(1) 2-吡啶酮及其团簇的振动光谱和团簇结构。(2)不同分子苯并硝基簇的结构和振动弛豫。(3)苯甲醇转子及其水溶剂化簇的结构研究。